/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the OpenSimulator Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Threading;
using System.Text;
using System.Xml;
using System.Xml.Serialization;
using log4net;
using OpenMetaverse;
using OpenMetaverse.Packets;
using OpenSim.Framework;
using OpenSim.Region.Framework.Interfaces;
using OpenSim.Region.Framework.Scenes.Serialization;
using OpenSim.Region.PhysicsModules.SharedBase;
using PermissionMask = OpenSim.Framework.PermissionMask;

namespace OpenSim.Region.Framework.Scenes
{
    #region Enumerations

    [Flags]
    public enum Changed : uint
    {
        INVENTORY = 1,
        COLOR = 2,
        SHAPE = 4,
        SCALE = 8,
        TEXTURE = 16,
        LINK = 32,
        ALLOWED_DROP = 64,
        OWNER = 128,
        REGION = 256,
        TELEPORT = 512,
        REGION_RESTART = 1024,
        MEDIA = 2048,
        MATERIAL = 4096,
        ANIMATION = 16384,
        POSITION = 32768
    }

    [Flags]
    public enum TextureAnimFlags : byte
    {
        NONE = 0x00,
        ANIM_ON = 0x01,
        LOOP = 0x02,
        REVERSE = 0x04,
        PING_PONG = 0x08,
        SMOOTH = 0x10,
        ROTATE = 0x20,
        SCALE = 0x40
    }

    public enum PrimType : int
    {
        BOX = 0,
        CYLINDER = 1,
        PRISM = 2,
        SPHERE = 3,
        TORUS = 4,
        TUBE = 5,
        RING = 6,
        SCULPT = 7
    }

    #endregion Enumerations

    public class SceneObjectPart : EntityBase, IDisposable
    {
        /// <value>
        /// Denote all sides of the prim
        /// </value>
        public const int ALL_SIDES = -1;

        private const scriptEvents PhysicsNeededSubsEvents = (
                    scriptEvents.collision | scriptEvents.collision_start | scriptEvents.collision_end |
                    scriptEvents.land_collision | scriptEvents.land_collision_start | scriptEvents.land_collision_end
                    );
        private const scriptEvents PhyscicsPhantonSubsEvents = (
                    scriptEvents.land_collision | scriptEvents.land_collision_start | scriptEvents.land_collision_end
                    );
        private const scriptEvents PhyscicsVolumeDtcSubsEvents = (
                    scriptEvents.collision_start | scriptEvents.collision_end
                    );

        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        /// <summary>
        /// Dynamic attributes can be created and deleted as required.
        /// </summary>
        public DAMap DynAttrs { get; set; }

        private DOMap m_dynObjs;

        /// <summary>
        /// Dynamic objects that can be created and deleted as required.
        /// </summary>
        public DOMap DynObjs
        {
            get
            {
                m_dynObjs ??= new DOMap();
                return m_dynObjs;
            }

            set
            {
                m_dynObjs = value;
            }
        }

        /// <value>
        /// Is this a root part?
        /// </value>
        /// <remarks>
        /// This will return true even if the whole object is attached to an avatar.
        /// </remarks>
        public bool IsRoot
        {
            get { return Object.ReferenceEquals(ParentGroup.RootPart, this); }
        }

        /// <summary>
        /// Is an explicit sit target set for this part?
        /// </summary>
        public bool IsSitTargetSet
        {
            get
            {
                // assume SitTargetOrientation is normalized (as needed elsewhere)
                if( !SitTargetPosition.IsZero() || !SitTargetOrientation.IsIdentityOrZero())
                    return true;
                return false;
            }
        }

        #region Fields

        public bool AllowedDrop;

        public bool DIE_AT_EDGE;

        public bool RETURN_AT_EDGE;

        public bool BlockGrab { get; set; }

        public bool StatusSandbox;

        public Vector3 StatusSandboxPos;

        [XmlIgnore]
        public int PseudoCRC; // this is local to region. should only be stored on its db.
                              // This is just a number that needs to change to invalidate prim data caches

        [XmlIgnore]
        public int[] PayPrice = {-2,-2,-2,-2,-2};

        [XmlIgnore]
        /// <summary>
        /// The representation of this part in the physics scene.
        /// </summary>
        /// <remarks>
        /// If you use this property more than once in a section of code then you must take a reference and use that.
        /// If another thread is simultaneously turning physics off on this part then this refernece could become
        /// null at any time.
        /// </remarks>
        public PhysicsActor PhysActor { get; set; }

        //Xantor 20080528 Sound stuff:
        //  Note: This isn't persisted in the database right now, as the fields for that aren't just there yet.
        //        Not a big problem as long as the script that sets it remains in the prim on startup.
        //        for SL compatibility it should be persisted though (set sound / displaytext / particlesystem, kill script)

        public UUID Sound;

        public byte SoundFlags;

        public double SoundGain;

        public double SoundRadius;

        /// <summary>
        /// Should sounds played from this prim be queued?
        /// </summary>
        /// <remarks>
        /// This should only be changed by sound modules.  It is up to sound modules as to how they interpret this setting.
        /// </remarks>
        public bool SoundQueueing { get; set; }

        [XmlIgnore]
        public Quaternion AttachRotation = Quaternion.Identity;

        private int m_CollisionFilterType = 0; // -1 not in use, 0 accept false, 1 accept true
        private string m_CollisionFilterString = string.Empty;

        /// <value>
        /// The UUID of the user inventory item from which this object was rezzed if this is a root part.
        /// If UUID.Zero then either this is not a root part or there is no connection with a user inventory item.
        /// </value>
        private UUID m_fromUserInventoryItemID;

        public UUID FromUserInventoryItemID
        {
            get { return m_fromUserInventoryItemID; }
            set { m_fromUserInventoryItemID = value; }
        }

        public scriptEvents AggregatedScriptEvents;

        public Vector3 AttachedPos  { get; set; }

        // rotation locks on local X,Y and or Z axis bit flags
        // bits are as in llSetStatus defined in SceneObjectGroup.axisSelect enum
        // but reversed logic: bit cleared means free to rotate
        public byte RotationAxisLocks = 0;

        // WRONG flag in libOmvPrimFlags
        private const uint primFlagVolumeDetect = (uint)PrimFlags.JointLP2P;

        public bool VolumeDetectActive
        {
            get
            {
                return (m_flags & (PrimFlags)primFlagVolumeDetect) != 0;
            }
            set
            {
                if(value)
                    m_flags |= (PrimFlags)primFlagVolumeDetect;
                else
                    m_flags &= (PrimFlags)(~primFlagVolumeDetect);
            }
        }

        public bool IsWaitingForFirstSpinUpdatePacket;

        public Quaternion SpinOldOrientation = Quaternion.Identity;

        protected bool m_APIDActive = false;
        protected Quaternion m_APIDTarget = Quaternion.Identity;
        protected float m_APIDDamp = 0;
        protected float m_APIDStrength = 0;

        /// <summary>
        /// This part's inventory
        /// </summary>
        public IEntityInventory Inventory
        {
            get { return m_inventory; }
        }
        protected SceneObjectPartInventory m_inventory;

        public bool Undoing;

        public bool IgnoreUndoUpdate = false;

        private float m_damage = -1.0f;
        private byte[] m_TextureAnimation;
        private byte m_clickAction;
        private Color m_color = Color.Black;
        private List<uint> m_lastColliders = new List<uint>();
        private bool m_lastLandCollide;
        private int m_linkNum;

        private int m_scriptAccessPin;

        private Dictionary<UUID, scriptEvents> m_scriptEvents = new Dictionary<UUID, scriptEvents>();
        private Quaternion m_sitTargetOrientation = Quaternion.Identity;
        private Vector3 m_sitTargetPosition;
        private string m_sitAnimation = "SIT";
        private UndoRedoState m_UndoRedo = null;
        private readonly object m_UndoLock = new object();

        private bool m_passTouches = false;
        private bool m_passCollisions = false;

        protected Vector3 m_acceleration;
        protected Vector3 m_angularVelocity;

        //unkown if this will be kept, added as a way of removing the group position from the group class
        protected Vector3 m_groupPosition;
        protected Material m_material = OpenMetaverse.Material.Wood;
        protected Vector3 m_offsetPosition;

        protected SceneObjectGroup m_parentGroup;
        protected byte[] m_particleSystem = Utils.EmptyBytes;
        protected double m_particleSystemExpire = -1;
        protected ulong m_regionHandle;
        protected Quaternion m_rotationOffset = Quaternion.Identity;
        protected PrimitiveBaseShape m_shape;

        protected Vector3 m_lastPosition;
        protected Quaternion m_lastRotation;
        protected Vector3 m_lastVelocity;
        protected Vector3 m_lastAcceleration; // acceleration is a derived var with high noise
        protected Vector3 m_lastAngularVelocity;
        protected double m_lastUpdateSentTime;
        protected float m_buoyancy = 0.0f;
        protected Vector3 m_force;
        protected Vector3 m_torque;

        protected byte m_physicsShapeType = (byte)PhysShapeType.prim;
        protected float m_density = 1000.0f; // in kg/m^3
        protected float m_gravitymod = 1.0f;
        protected float m_friction = 0.6f; // wood
        protected float m_bounce = 0.5f; // wood


        protected bool m_isSelected = false;

        // TODO: Those have to be changed into persistent properties at some later point,
        // or sit-camera on vehicles will break on sim-crossing.
        private Vector3 m_cameraEyeOffset;
        private Vector3 m_cameraAtOffset;
        private bool m_forceMouselook;


        // 0 for default collision sounds, -1 for script disabled sound 1 for script defined sound
        private sbyte m_collisionSoundType = 0;
        private UUID m_collisionSound;
        private float m_collisionSoundVolume;

        private int LastColSoundSentTime;

        private SOPVehicle m_vehicleParams = null;

        private PhysicsInertiaData m_physicsInertia;

        public KeyframeMotion KeyframeMotion
        {
            get; set;
        }


        #endregion Fields

//        ~SceneObjectPart()
//        {
//            Console.WriteLine(
//                "[SCENE OBJECT PART]: Destructor called for {0}, local id {1}, parent {2} {3}",
//                Name, LocalId, ParentGroup.Name, ParentGroup.LocalId);
//            m_log.DebugFormat(
//                "[SCENE OBJECT PART]: Destructor called for {0}, local id {1}, parent {2} {3}",
//                Name, LocalId, ParentGroup.Name, ParentGroup.LocalId);
//        }

        #region Constructors

        /// <summary>
        /// No arg constructor called by region restore db code
        /// </summary>
        public SceneObjectPart()
        {
            m_TextureAnimation = Utils.EmptyBytes;
            m_particleSystem = Utils.EmptyBytes;
            Rezzed = DateTime.UtcNow;
            //Description = String.Empty;
            PseudoCRC = (int)DateTime.UtcNow.Ticks; // random could be as good; fallbak if not on region db
            m_inventory = new SceneObjectPartInventory(this);
            LastColSoundSentTime = Util.EnvironmentTickCount();
        }

        public static osUTF8 defaultName = new osUTF8("Object", true);
        /// <summary>
        /// Create a completely new SceneObjectPart (prim).  This will need to be added separately to a SceneObjectGroup
        /// </summary>
        /// <param name="ownerID"></param>
        /// <param name="shape"></param>
        /// <param name="position"></param>
        /// <param name="rotationOffset"></param>
        /// <param name="offsetPosition"></param>

        public SceneObjectPart(
            UUID ownerID, PrimitiveBaseShape shape, Vector3 groupPosition,
            Quaternion rotationOffset, Vector3 offsetPosition) : this()
        {
            osUTF8Name = defaultName;
            osUTF8LargeName = defaultName;

            CreationDate = (int)Utils.DateTimeToUnixTime(Rezzed);
            RezzerID = LastOwnerID = CreatorID = OwnerID = ownerID;
            UUID = UUID.Random();
            Shape = shape;
            OwnershipCost = 0;
            ObjectSaleType = 0;
            SalePrice = 0;
            Category = 0;
            GroupPosition = groupPosition;
            OffsetPosition = offsetPosition;
            RotationOffset = rotationOffset;
            Velocity = Vector3.Zero;
            AngularVelocity = Vector3.Zero;
            Acceleration = Vector3.Zero;
            APIDActive = false;
            m_flags = 0;
            CreateSelected = false;
            TrimPermissions();
            AggregateInnerPerms();
        }

        ~SceneObjectPart()
        {
            Dispose(false);
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        private bool disposed = false;
        protected void Dispose(bool disposing)
        {
            if (!disposed)
            {
                disposed = true;
                IsDeleted = true;

                if (KeyframeMotion != null)
                {
                    KeyframeMotion.Delete();
                    KeyframeMotion = null;
                }
                if (PhysActor != null)
                    RemoveFromPhysics();

                if (m_inventory != null)
                {
                    m_inventory.Dispose();
                    m_inventory = null;
                }
            }
        }

        #endregion Constructors

        #region XML Schema

        private UUID _rezzerID;
        private UUID _lastOwnerID;
        private UUID _ownerID;
        private UUID _groupID;
        private int _ownershipCost;
        private byte _objectSaleType;
        private int _salePrice;
        private uint _category;
        private Int32 _creationDate;
        private uint _parentID = 0;
        private uint _baseMask = (uint)(PermissionMask.All | PermissionMask.Export);
        private uint _ownerMask = (uint)(PermissionMask.All | PermissionMask.Export);
        private uint _groupMask = (uint)PermissionMask.None;
        private uint _everyoneMask = (uint)PermissionMask.None;
        private uint _nextOwnerMask = (uint)(PermissionMask.Move | PermissionMask.Transfer);
        private PrimFlags m_flags = PrimFlags.None;
        private PrimFlags m_localFlags = PrimFlags.None;
        private DateTime m_expires;
        private DateTime m_rezzed;
        private bool m_createSelected = false;

        private UUID _creatorID;
        public UUID CreatorID
        {
            get { return _creatorID; }
            set { _creatorID = value; }
        }

        private string m_creatorData = string.Empty;
        /// <summary>
        /// Data about the creator in the form home_url;name
        /// </summary>
        public string CreatorData
        {
            get { return m_creatorData; }
            set { m_creatorData = value; }
        }

        /// <summary>
        /// Used by the DB layer to retrieve / store the entire user identification.
        /// The identification can either be a simple UUID or a string of the form
        /// uuid[;home_url[;name]]
        /// </summary>
        public string CreatorIdentification
        {
            get
            {
                if (!string.IsNullOrEmpty(CreatorData))
                    return CreatorID.ToString() + ';' + CreatorData;
                else
                    return CreatorID.ToString();
            }
            set
            {
                CreatorData = string.Empty;
                if (string.IsNullOrEmpty(value))
                    return;

                // value is uuid  or uuid;homeuri;firstname lastname
                string[] parts = value.Split(';');
                if (parts.Length > 0)
                {

                    _ = UUID.TryParse(parts[0], out UUID uuid);
                    CreatorID = uuid;

                    if (parts.Length > 1)
                    {
                        CreatorData = parts[1];
                        if (!CreatorData.EndsWith("/"))
                            CreatorData += "/";
                        if (parts.Length > 2)
                            CreatorData += ';' + parts[2];
                        else
                            CreatorData += ";Unknown User";
                    }
                }
            }
        }

        /// <summary>
        /// A relic from when we we thought that prims contained folder objects. In
        /// reality, prim == folder
        /// Exposing this is not particularly good, but it's one of the least evils at the moment to see
        /// folder id from prim inventory item data, since it's not (yet) actually stored with the prim.
        /// </summary>
        public UUID FolderID
        {
            get { return UUID; }
            set { } // Don't allow assignment, or legacy prims wil b0rk - but we need the setter for legacy serialization.
        }

        /// <value>
        /// Access should be via Inventory directly - this property temporarily remains for xml serialization purposes
        /// </value>
        public uint InventorySerial
        {
            get { return m_inventory.Serial; }
            set { m_inventory.Serial = value; }
        }

        /// <value>
        /// Get the inventory list
        /// </value>
        public TaskInventoryDictionary TaskInventory
        {
            get {
                return m_inventory.Items;
            }
            set {
                m_inventory.Items = value;
            }
        }

        /// <summary>
        /// This is idential to the Flags property, except that the returned value is uint rather than PrimFlags
        /// </summary>
        [Obsolete("Use Flags property instead")]
        public uint ObjectFlags
        {
            get { return (uint)Flags; }
            set { Flags = (PrimFlags)value; }
        }

        public override UUID UUID
        {
            get { return m_uuid; }
            set
            {
                m_uuid = value;

                // This is necessary so that TaskInventoryItem parent ids correctly reference the new uuid of this part
                Inventory?.ResetObjectID();
            }
        }
 
        // several code still depends on large uncontroled names
        private osUTF8 osUTF8LargeName;
        public override string Name
        {
            get
            {
                return osUTF8LargeName == null ? string.Empty : osUTF8LargeName.ToString();
            }
            set
            {
                if(string.IsNullOrEmpty(value))
                {
                    osUTF8LargeName = null;
                    osUTF8Name = null;
                    PhysicsActor pa = PhysActor;
                    if (pa != null)
                        pa.SOPName = string.Empty;
                }
                else
                {
                    osUTF8LargeName = new osUTF8(value);
                    osUTF8Name = new osUTF8(value, 63);
                    PhysicsActor pa = PhysActor;
                    if (pa != null)
                        pa.SOPName = value;
                }
                ParentGroup?.InvalidatePartsLinkMaps();
            }
        }

        [XmlIgnore]
        public bool PassTouches
        {
            get { return m_passTouches; }
            set
            {
                m_passTouches = value;

                if (ParentGroup != null)
                    ParentGroup.HasGroupChanged = true;
            }
        }

        public bool PassCollisions
        {
            get { return m_passCollisions; }
            set
            {
                m_passCollisions = value;

                if (ParentGroup != null)
                    ParentGroup.HasGroupChanged = true;
            }
        }

        public bool IsSelected
        {
            get { return m_isSelected; }
            set
            {
                m_isSelected = value;
                ParentGroup?.PartSelectChanged(value);
            }
        }

        protected bool APIDActive
        {
            get { return m_APIDActive; }
            set { m_APIDActive = value; }
        }

        protected Quaternion APIDTarget
        {
            get { return m_APIDTarget; }
            set { m_APIDTarget = value; }
        }

        protected float APIDDamp
        {
            get { return m_APIDDamp; }
            set { m_APIDDamp = value; }
        }

        protected float APIDStrength
        {
            get { return m_APIDStrength; }
            set { m_APIDStrength = value; }
        }

        public ulong RegionHandle
        {
            get { return m_regionHandle; }
            set { m_regionHandle = value; }
        }

        public int ScriptAccessPin
        {
            get { return m_scriptAccessPin; }
            set { m_scriptAccessPin = (int)value; }
        }

        public Byte[] TextureAnimation
        {
            get { return m_TextureAnimation; }
            set { m_TextureAnimation = value; }
        }

        public Byte[] ParticleSystem
        {
            get
            {
                if(m_particleSystemExpire > 0 && Util.GetTimeStamp() > m_particleSystemExpire)
                {
                    m_particleSystemExpire = -1;
                    m_particleSystem = Array.Empty<byte>();
                }
                return m_particleSystem;
            }
            set { m_particleSystem = value; }
        }

        public DateTime Expires
        {
            get { return m_expires; }
            set { m_expires = value; }
        }

        public DateTime Rezzed
        {
            get { return m_rezzed; }
            set { m_rezzed = value; }
        }


        public float Damage
        {
            get { return m_damage; }
            set { m_damage = value; }
        }

        public void setGroupPosition(Vector3 pos)
        {
            m_groupPosition = pos;
        }

        /// <summary>
        /// The position of the entire group that this prim belongs to.
        /// </summary>
        ///

        public Vector3 GroupPosition
        {
            get
            {
                // If this is a linkset, we don't want the physics engine mucking up our group position here.
                if (_parentID == 0)
                {
                    PhysicsActor actor = PhysActor;
                    if (actor != null)
                        m_groupPosition = actor.Position;
                    return m_groupPosition;
                }

                // If I'm an attachment, my position is reported as the position of who I'm attached to
                if (ParentGroup.IsAttachment)
                {
                    if(ParentGroup.Scene.TryGetScenePresence(ParentGroup.AttachedAvatar, out ScenePresence sp))
                        return sp.AbsolutePosition;
                }

                // use root prim's group position. Physics may have updated it
                if (ParentGroup.RootPart != this)
                    m_groupPosition = ParentGroup.RootPart.GroupPosition;
                return m_groupPosition;
            }
            set
            {
                m_groupPosition = value;
                PhysicsActor actor = PhysActor;
                if (actor != null && ParentGroup.Scene.PhysicsScene != null)
                {
                    try
                    {
                        // Root prim actually goes at Position
                        if (_parentID == 0)
                        {
                            actor.Position = value;
                        }
                        else
                        {
                            // The physics engine always sees all objects (root or linked) in world coordinates.
                            actor.Position = GetWorldPosition();
                            actor.Orientation = GetWorldRotation();
                        }
                    }
                    catch (Exception e)
                    {
                        m_log.ErrorFormat("[SCENEOBJECTPART]: GROUP POSITION. {0}", e);
                    }
                }
            }
        }

        public void setOffsetPosition(Vector3 pos)
        {
            m_offsetPosition = pos;
        }

        public Vector3 OffsetPosition
        {
            get { return m_offsetPosition; }
            set
            {
                Vector3 oldpos = m_offsetPosition;
                m_offsetPosition = value;

                if (ParentGroup != null && !ParentGroup.IsDeleted)
                {
                    if((oldpos - m_offsetPosition).LengthSquared() > 1.0f)
                        ParentGroup.InvalidBoundsRadius();

                    PhysicsActor actor = PhysActor;
                    if (_parentID != 0 && actor != null)
                    {
                        actor.Position = GetWorldPosition();
                        actor.Orientation = GetWorldRotation();
                    }

                    if (!m_parentGroup.m_dupeInProgress)
                    {
                        List<ScenePresence> avs = ParentGroup.GetSittingAvatars();
                        foreach (ScenePresence av in avs)
                        {
                            if (av.ParentID == m_localId)
                            {
                                Vector3 offset = (m_offsetPosition - oldpos);
                                av.AbsolutePosition += offset;
//                                av.SendAvatarDataToAllAgents();
                                av.SendTerseUpdateToAllClients();
                            }
                        }
                    }
                }
                TriggerScriptChangedEvent(Changed.POSITION);
            }
        }

        public Vector3 RelativePosition
        {
            get
            {
                if (IsRoot)
                {
                    if (ParentGroup.IsAttachment)
                        return AttachedPos;
                    else
                        return AbsolutePosition;
                }
                else
                {
                    return OffsetPosition;
                }
            }
        }

        public void setRotationOffset(Quaternion q)
        {
            m_rotationOffset = q;
        }

        public Quaternion RotationOffset
        {
            get
            {
                // We don't want the physics engine mucking up the rotations in a linkset
                PhysicsActor actor = PhysActor;
                // If this is a root of a linkset, the real rotation is what the physics engine thinks.
                // If not a root prim, the offset rotation is computed by SOG and is relative to the root.
                if (_parentID == 0 && (Shape.PCode != 9 || Shape.State == 0) && actor != null)
                    m_rotationOffset = actor.Orientation;

                return m_rotationOffset;
            }

            set
            {
//                StoreUndoState();
                m_rotationOffset = value;
                m_rotationOffset.Normalize();

                PhysicsActor actor = PhysActor;
                if (actor != null)
                {
                    try
                    {
                        // Root prim gets value directly
                        if (_parentID == 0)
                        {
                            actor.Orientation = value;
                            //m_log.Info("[PART]: RO1:" + actor.Orientation.ToString());
                        }
                        else
                        {
                            // Child prim we have to calculate it's world rotationwel
                            Quaternion resultingrotation = GetWorldRotation();
                            actor.Orientation = resultingrotation;
                            //m_log.Info("[PART]: RO2:" + actor.Orientation.ToString());
                        }
                    }
                    catch (Exception ex)
                    {
                        m_log.Error("[SCENEOBJECTPART]: ROTATIONOFFSET" + ex.Message);
                    }
                }
            }
        }

        /// <summary></summary>
        public override Vector3 Velocity
        {
            get
            {
                PhysicsActor actor = PhysActor;
                if (actor != null)
                {
                    if (actor.IsPhysical)
                    {
                        m_velocity = actor.Velocity;
                    }
                }

                return m_velocity;
            }

            set
            {
                if (Util.IsNanOrInfinity(value))
                    m_velocity = Vector3.Zero;
                else
                    m_velocity = value;

                PhysicsActor actor = PhysActor;
                if (actor is not null && actor.IsPhysical)
                    actor.Velocity = m_velocity;
            }
        }

        /// <summary>Update angular velocity and schedule terse update.</summary>
        public void UpdateAngularVelocity(Vector3 avel)
        {
            AngularVelocity = avel;
            ScheduleTerseUpdate();
            ParentGroup.HasGroupChanged = true;
        }

        /// <summary>Get or set angular velocity. Does not schedule update.</summary>
        public Vector3 AngularVelocity
        {
            get
            {
                PhysicsActor actor = PhysActor;
                if ((actor != null) && actor.IsPhysical && ParentGroup.RootPart == this)
                {
                    m_angularVelocity = actor.RotationalVelocity;
                }
                return m_angularVelocity;
            }
            set
            {
                if (Util.IsNanOrInfinity(value))
                    m_angularVelocity = Vector3.Zero;
                else
                    m_angularVelocity = value;

                PhysicsActor actor = PhysActor;
                if ((actor != null) && actor.IsPhysical && ParentGroup.RootPart == this)
                {
                    actor.RotationalVelocity = m_angularVelocity;
                }
            }
        }

        /// <summary></summary>
        public Vector3 Acceleration
        {
            get
            {
                PhysicsActor actor = PhysActor;
                if (actor != null && actor.IsPhysical)
                {
                    m_acceleration = actor.Acceleration;
                }
                return m_acceleration;
            }

            set
            {
                if (Util.IsNanOrInfinity(value))
                    m_acceleration = Vector3.Zero;
                else
                    m_acceleration = value;

                PhysicsActor actor = PhysActor;
                if ((actor != null) && actor.IsPhysical && ParentGroup.RootPart == this)
                {
                   actor.Acceleration = m_acceleration;
                }
            }
        }

        public osUTF8 osUTF8Description;
        public string Description
        {
            get {return osUTF8Description == null ? string.Empty : osUTF8Description.ToString(); }
            set { osUTF8Description = string.IsNullOrEmpty(value) ? null : new osUTF8(value, 127);}
        }

        /// <value>
        /// Text color.
        /// </value>
        public Color Color
        {
            get { return m_color; }
            set { m_color = value; }
        }

        public osUTF8 osUTF8Text;
        public string Text
        {
            get { return osUTF8Text == null ? string.Empty : osUTF8Text.ToString(); }
            set { osUTF8Text = string.IsNullOrEmpty(value) ? null : new osUTF8(value, 254); }
        }

        public osUTF8 osUTF8SitName;
        public string SitName
        {
            get { return osUTF8SitName == null ? string.Empty : osUTF8SitName.ToString(); }
            set { osUTF8SitName = string.IsNullOrEmpty(value) ? null : new osUTF8(value, 36); }
        }

        public osUTF8 osUTF8TouchName;
        public string TouchName
        {
            get { return osUTF8TouchName == null ? string.Empty : osUTF8TouchName.ToString(); }
            set { osUTF8TouchName = string.IsNullOrEmpty(value) ? null : new osUTF8(value, 36); }
        }

        public int LinkNum
        {
            get { return m_linkNum; }
            set
            {
//                if (ParentGroup != null)
//                {
//                    m_log.DebugFormat(
//                        "[SCENE OBJECT PART]: Setting linknum of {0}@{1} to {2} from {3}",
//                        Name, AbsolutePosition, value, m_linkNum);
//                    Util.PrintCallStack();
//                }

                m_linkNum = value;
            }
        }

        public byte ClickAction
        {
            get { return m_clickAction; }
            set
            {
                m_clickAction = value;
            }
        }

        public PrimitiveBaseShape Shape
        {
            get { return m_shape; }
            set
            {
                m_shape = value;
            }
        }

        /// <summary>
        /// Change the scale of this part.
        /// </summary>
        public Vector3 Scale
        {
            get { return m_shape.Scale; }
            set
            {
                if (m_shape is not null)
                {
                    Vector3 oldscale = m_shape.Scale;
                    m_shape.Scale = value;
                    if (ParentGroup is not null && ((value - oldscale).LengthSquared() >1.0f))
                        ParentGroup.InvalidBoundsRadius();
                    PhysicsActor actor = PhysActor;
                    if (actor is not null)
                    {
                        if (ParentGroup.Scene is not  null)
                        {
                            if (ParentGroup.Scene.PhysicsScene != null)
                            {
                                actor.Size = m_shape.Scale;
                            }
                        }
                    }
                }

                TriggerScriptChangedEvent(Changed.SCALE);
            }
        }

        public float maxSimpleArea()
        {
            float a,b;
            float sx = m_shape.Scale.X;
            float sy = m_shape.Scale.Y;
            float sz = m_shape.Scale.Z;

            if( sx > sy)
            {
                a = sx;
                if(sy  > sz)
                    b = sy;
                else
                    b = sz;
            }
            else
            {
                a = sy;
                if(sx  > sz)
                    b = sx;
                else
                    b = sz;
            }

            return a * b;
        }

        public PrimUpdateFlags UpdateFlag { get; set; }

        public PrimUpdateFlags GetAndClearUpdateFlag()
        {
            lock(UpdateFlagLock)
            {
                PrimUpdateFlags ret = UpdateFlag;
                UpdateFlag = PrimUpdateFlags.None;
                return ret;
            }
        }

        private readonly object UpdateFlagLock = new object();

        /// <summary>
        /// Used for media on a prim.
        /// </summary>
        /// Do not change this value directly - always do it through an IMoapModule.
        public osUTF8 osUTFMediaUrl;
        public string MediaUrl
        {
            get
            {
                return osUTFMediaUrl == null ? string.Empty : osUTFMediaUrl.ToString();
            }

            set
            {
                osUTF8 old = osUTFMediaUrl;
                if (string.IsNullOrEmpty(value))
                {
                    osUTFMediaUrl = null;
                    if (old != null && ParentGroup != null)
                        ParentGroup.HasGroupChanged = true;
                }
                else
                {
                    osUTFMediaUrl = new osUTF8(value, 254);

                    if (ParentGroup != null && !osUTFMediaUrl.Equals(old))
                        ParentGroup.HasGroupChanged = true;
                }
            }
        }

        public bool CreateSelected
        {
            get { return m_createSelected; }
            set
            {
//                m_log.DebugFormat("[SOP]: Setting CreateSelected to {0} for {1} {2}", value, Name, UUID);
                m_createSelected = value;
            }
        }

        #endregion

//---------------
#region Public Properties with only Get

        public override Vector3 AbsolutePosition
        {
            get
            {
                return _parentID == 0 ? GroupPosition : GroupPosition + m_offsetPosition * ParentGroup.RootPart.RotationOffset;
            }
        }

        public SceneObjectGroup ParentGroup
        {
            get { return m_parentGroup; }
            private set { m_parentGroup = value; }
        }

        public scriptEvents ScriptEvents
        {
            get { return AggregatedScriptEvents; }
        }

        public Quaternion SitTargetOrientation
        {
            get { return m_sitTargetOrientation; }
            set
            {
                m_sitTargetOrientation = value;
//                m_log.DebugFormat("[SCENE OBJECT PART]: Set sit target orientation {0} for {1} {2}", m_sitTargetOrientation, Name, LocalId);
            }
        }

        public Vector3 SitTargetPosition
        {
            get { return m_sitTargetPosition; }
            set
            {
                m_sitTargetPosition = value;
//                m_log.DebugFormat("[SCENE OBJECT PART]: Set sit target position to {0} for {1} {2}", m_sitTargetPosition, Name, LocalId);
            }
        }

        // This sort of sucks, but I'm adding these in to make some of
        // the mappings more consistant.
        public Vector3 SitTargetPositionLL
        {
            get { return m_sitTargetPosition; }
            set { m_sitTargetPosition = value; }
        }

        public Quaternion SitTargetOrientationLL
        {
            get { return m_sitTargetOrientation; }
            set { m_sitTargetOrientation = value; }
        }

        public float SitActiveRange { get; set;}
        public Vector3 StandOffset { get; set;}

        public bool Stopped
        {
            get {
                double threshold = 0.02;
                return (Math.Abs(Velocity.X) < threshold &&
                        Math.Abs(Velocity.Y) < threshold &&
                        Math.Abs(Velocity.Z) < threshold &&
                        Math.Abs(AngularVelocity.X) < threshold &&
                        Math.Abs(AngularVelocity.Y) < threshold &&
                        Math.Abs(AngularVelocity.Z) < threshold);
            }
        }

        /// <summary>
        /// The parent ID of this part.
        /// </summary>
        /// <remarks>
        /// If this is a root part which is not attached to an avatar then the value will be 0.
        /// If this is a root part which is attached to an avatar then the value is the local id of that avatar.
        /// If this is a child part then the value is the local ID of the root part.
        /// </remarks>
        public uint ParentID
        {
            get { return _parentID; }
            set { _parentID = value; }
        }

        public int CreationDate
        {
            get { return _creationDate; }
            set { _creationDate = value; }
        }

        public uint Category
        {
            get { return _category; }
            set { _category = value; }
        }

        public int SalePrice
        {
            get { return _salePrice; }
            set { _salePrice = value; }
        }

        public byte ObjectSaleType
        {
            get { return _objectSaleType; }
            set { _objectSaleType = value; }
        }

        public int OwnershipCost
        {
            get { return _ownershipCost; }
            set { _ownershipCost = value; }
        }

        public UUID GroupID
        {
            get { return _groupID; }
            set { _groupID = value; }
        }

        public UUID OwnerID
        {
            get { return _ownerID; }
            set { _ownerID = value; }
        }

        public UUID LastOwnerID
        {
            get { return _lastOwnerID; }
            set {
             _lastOwnerID = value; }
        }

        public UUID RezzerID
        {
            get { return _rezzerID; }
            set { _rezzerID = value; }
        }

        public uint BaseMask
        {
            get { return _baseMask; }
            set { _baseMask = value; }
        }

        public uint OwnerMask
        {
            get { return _ownerMask; }
            set { _ownerMask = value; }
        }

        public uint GroupMask
        {
            get { return _groupMask; }
            set { _groupMask = value; }
        }

        public uint EveryoneMask
        {
            get { return _everyoneMask; }
            set { _everyoneMask = value; }
        }

        public uint NextOwnerMask
        {
            get { return _nextOwnerMask; }
            set { _nextOwnerMask = value; }
        }

        /// <summary>
        /// Property flags.  See OpenMetaverse.PrimFlags
        /// </summary>
        /// <remarks>
        /// Example properties are PrimFlags.Phantom and PrimFlags.DieAtEdge
        /// </remarks>
        public PrimFlags Flags
        {
            get { return m_flags; }
            set
            {
                //m_log.DebugFormat("[SOP]: Setting flags for {0} {1} to {2}", UUID, Name, value);
                m_flags = value & ~(PrimFlags.Touch | PrimFlags.Money | PrimFlags.AllowInventoryDrop);
            }
        }

        /// <summary>
        /// ID of the avatar that is sat on us if we have a sit target.  If there is no such avatar then is UUID.Zero
        /// </summary>
        public UUID SitTargetAvatar { get; set; }

        /// <summary>
        /// IDs of all avatars sat on this part.
        /// </summary>
        /// <remarks>
        /// We need to track this so that we can stop sat upon prims from being attached.
        /// </remarks>
        /// <value>
        /// null if there are no sitting avatars.  This is to save us create a hashset for every prim in a scene.
        /// </value>
        private HashSet<ScenePresence> m_sittingAvatars;

        public virtual UUID RegionID
        {
            get
            {
                if (ParentGroup.Scene != null)
                    return ParentGroup.Scene.RegionInfo.RegionID;
                else
                    return UUID.Zero;
            }
            set {} // read only
        }

        private UUID _parentUUID = UUID.Zero;

        public UUID ParentUUID
        {
            get
            {
                if (ParentGroup != null)
                    _parentUUID = ParentGroup.UUID;

                return _parentUUID;
            }

            set { _parentUUID = value; }
        }

        public string SitAnimation
        {
            get { return m_sitAnimation; }
            set { m_sitAnimation = value; }
        }

        public readonly UUID invalidCollisionSoundUUID = new UUID("ffffffff-ffff-ffff-ffff-ffffffffffff");

        // 0 for default collision sounds, -1 for script disabled sound 1 for script defined sound
        // runtime thing.. do not persist
        [XmlIgnore]
        public sbyte CollisionSoundType
        {
            get
            {
                return m_collisionSoundType;
            }
            set
            {
                UUID old = m_collisionSound;

                m_collisionSoundType = value;
                if (value == -1)
                    m_collisionSound = invalidCollisionSoundUUID;
                else if (value == 0)
                    m_collisionSound = UUID.Zero;

                if(m_collisionSound != old && ParentGroup != null)
                    ParentGroup.HasGroupChanged = true;
            }
        }

        public UUID CollisionSound
        {
            get { return m_collisionSound; }
            set
            {
                UUID olds = m_collisionSound;
                m_collisionSound = value;

                if (value == invalidCollisionSoundUUID)
                    m_collisionSoundType = -1;
                else if (value.IsZero())
                    m_collisionSoundType = 0;
                else
                    m_collisionSoundType = 1;

                if(m_collisionSound != olds && ParentGroup != null)
                    ParentGroup.HasGroupChanged = true;
            }
        }

        public float CollisionSoundVolume
        {
            get { return m_collisionSoundVolume; }
            set
            {
                float oldvalue = m_collisionSoundVolume;
                if(value >= 0)
                    m_collisionSoundVolume = value;
                else
                    m_collisionSoundVolume = 0.0f;
                if(m_collisionSoundVolume != oldvalue && ParentGroup != null)
                    ParentGroup.HasGroupChanged = true;
            }
        }

        public float Buoyancy
        {
            get
            {
                if (ParentGroup.RootPart == this)
                    return m_buoyancy;

                return ParentGroup.RootPart.Buoyancy;
            }
            set
            {
                if (ParentGroup != null && ParentGroup.RootPart != null && ParentGroup.RootPart != this)
                {
                    ParentGroup.RootPart.Buoyancy = value;
                    return;
                }
                m_buoyancy = value;
                if (PhysActor != null)
                    PhysActor.Buoyancy = value;
            }
        }

        public Vector3 Force
        {
            get
            {
                if (ParentGroup.RootPart == this)
                    return m_force;

                return ParentGroup.RootPart.Force;
            }

            set
            {
                if (ParentGroup != null && ParentGroup.RootPart != null && ParentGroup.RootPart != this)
                {
                    ParentGroup.RootPart.Force = value;
                    return;
                }
                m_force = value;
                if (PhysActor != null)
                    PhysActor.Force = value;
            }
        }

        public Vector3 Torque
        {
            get
            {
                if (ParentGroup.RootPart == this)
                    return m_torque;

                return ParentGroup.RootPart.Torque;
            }

            set
            {
                if (ParentGroup != null && ParentGroup.RootPart != null && ParentGroup.RootPart != this)
                {
                    ParentGroup.RootPart.Torque = value;
                    return;
                }
                m_torque = value;
                if (PhysActor != null)
                    PhysActor.Torque = value;
            }
        }

        public byte Material
        {
            get { return (byte)m_material; }
            set
            {
                if (value >= 0 && value <= (byte)SOPMaterialData.MaxMaterial)
                {
                    bool update = false;

                    if (m_material != (Material)value)
                    {
                        update = true;
                        m_material = (Material)value;
                    }

                    if (m_friction != SOPMaterialData.friction(m_material))
                    {
                        update = true;
                        m_friction = SOPMaterialData.friction(m_material);
                    }

                    if (m_bounce != SOPMaterialData.bounce(m_material))
                    {
                        update = true;
                        m_bounce = SOPMaterialData.bounce(m_material);
                    }

                    if (update)
                    {
                        PhysActor?.SetMaterial((int)value);
                        if(ParentGroup != null)
                        {
                            ParentGroup.HasGroupChanged = true;
                            ScheduleFullUpdate();
                        }
                    }
                }
            }
        }

        // not a propriety to move to methods place later
        private bool HasMesh()
        {
            if (Shape != null && (Shape.SculptType == (byte)SculptType.Mesh))
                return true;
            return false;
        }

        // not a propriety to move to methods place later
        public byte DefaultPhysicsShapeType()
        {
            byte type;

            if (Shape != null && (Shape.SculptType == (byte)SculptType.Mesh))
                type = (byte)PhysShapeType.convex;
            else
                type = (byte)PhysShapeType.prim;

            return type;
        }

        [XmlIgnore]
        public bool UsesComplexCost
        {
            get
            {
                byte pst = PhysicsShapeType;
                if(pst == (byte) PhysShapeType.none || HasMesh())
                    return true;
                return false;
            }
        }

        [XmlIgnore]
        public float PhysicsCost
        {
            get
            {
                if(PhysicsShapeType == (byte)PhysShapeType.none)
                    return 0;

                float cost;
                if (PhysActor != null)
                    cost = PhysActor.PhysicsCost;
                else
                    cost = 0.1f;

                if ((m_flags & PrimFlags.Physics) != 0)
                    cost *= (1.0f + 0.01333f * Scale.LengthSquared()); // 0.01333 == 0.04/3
                return cost;
            }
        }

        [XmlIgnore]
        public float StreamingCost
        {
            get
            {
                //float cost = PhysActor is null ? 1.0f : PhysActor.StreamCost;
                return 1.0f; // disabled ?
            }
        }

        [XmlIgnore]
        public float SimulationCost
        {
            get
            {
                // ignoring scripts. Don't like considering them for this
                if((m_flags & PrimFlags.Physics) != 0)
                    return 1.0f;

                return 0.5f;
            }
        }

        public byte PhysicsShapeType
        {
            get
            {
//                if (PhysActor != null)
//                    m_physicsShapeType  = PhysActor.PhysicsShapeType;
                return m_physicsShapeType;
            }
            set
            {
                byte oldv = m_physicsShapeType;

                if (value >= 0 && value <= (byte)PhysShapeType.convex)
                {
                    if (value == (byte)PhysShapeType.none && ParentGroup != null && ParentGroup.RootPart == this)
                        m_physicsShapeType = DefaultPhysicsShapeType();
                    else
                        m_physicsShapeType = value;
                }
                else
                    m_physicsShapeType = DefaultPhysicsShapeType();

                if (m_physicsShapeType != oldv && ParentGroup != null)
                {
                    if (m_physicsShapeType == (byte)PhysShapeType.none)
                    {
                        if (PhysActor != null)
                        {
                            ParentGroup.Scene.RemovePhysicalPrim(1);
                            RemoveFromPhysics();
//                            Stop();
                        }
                    }
                    else if (PhysActor == null)
                    {
                        if(oldv == (byte)PhysShapeType.none)
                        {
                            ApplyPhysics((uint)m_flags, VolumeDetectActive, false);
                            UpdatePhysicsSubscribedEvents();
                        }
                    }
                    else
                        PhysActor.PhysicsShapeType = m_physicsShapeType;

                    ParentGroup.HasGroupChanged = true;
                }
            }
        }

        public float Density // in kg/m^3
        {
            get { return m_density; }
            set
            {
                if (value >=1 && value <= 22587.0)
                {
                    m_density = value;


                    if (ParentGroup != null)
                    {
                        ParentGroup.HasGroupChanged = true;
                        ScheduleFullUpdate();
                    }

                    PhysicsActor pa = PhysActor;
                    if (pa != null)
                        pa.Density = m_density;
                }
            }
        }

        public float GravityModifier
        {
            get { return m_gravitymod; }
            set
            {
                if( value >= -1 && value <=28.0f)
                {
                    m_gravitymod = value;

                    if (ParentGroup != null)
                    {
                        ParentGroup.HasGroupChanged = true;
                        ScheduleFullUpdate();
                    }

                    PhysicsActor pa = PhysActor;
                    if (pa != null)
                        pa.GravModifier = m_gravitymod;
                }
            }
        }

        public float Friction
        {
            get { return m_friction; }
            set
            {
                if (value >= 0 && value <= 255.0f)
                {
                    m_friction = value;

                    if (ParentGroup != null)
                    {
                        ParentGroup.HasGroupChanged = true;
                        ScheduleFullUpdate();
                    }

                    PhysicsActor pa = PhysActor;
                    if (pa != null)
                        pa.Friction = m_friction;
                }
            }
        }

        public float Restitution
        {
            get { return m_bounce; }
            set
            {
                if (value >= 0 && value <= 1.0f)
                {
                    m_bounce = value;

                    if (ParentGroup != null)
                    {
                        ParentGroup.HasGroupChanged = true;
                        ScheduleFullUpdate();
                    }

                    PhysicsActor pa = PhysActor;
                    if (pa != null)
                        pa.Restitution = m_bounce;
                }
            }
        }


        #endregion Public Properties with only Get

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        private static uint ApplyMask(uint val, bool set, uint mask)
        {
            return set ? val |= mask : val &= ~mask;
        }

        /// <summary>
        /// Clear all pending updates of parts to clients
        /// </summary>
        public void ClearUpdateSchedule()
        {
            lock(UpdateFlagLock)
                UpdateFlag = PrimUpdateFlags.None;
        }

        /// <summary>
        /// Send this part's properties (name, description, inventory serial, base mask, etc.) to a client
        /// </summary>
        /// <param name="client"></param>
        public void SendPropertiesToClient(IClientAPI client)
        {
            client.SendObjectPropertiesReply(this);
        }

        // TODO: unused:
        // private void handleTimerAccounting(uint localID, double interval)
        // {
        //     if (localID == LocalId)
        //     {
        //         float sec = (float)interval;
        //         if (m_parentGroup != null)
        //         {
        //             if (sec == 0)
        //             {
        //                 if (m_parentGroup.scriptScore + 0.001f >= float.MaxValue - 0.001)
        //                     m_parentGroup.scriptScore = 0;
        //
        //                 m_parentGroup.scriptScore += 0.001f;
        //                 return;
        //             }
        //
        //             if (m_parentGroup.scriptScore + (0.001f / sec) >= float.MaxValue - (0.001f / sec))
        //                 m_parentGroup.scriptScore = 0;
        //             m_parentGroup.scriptScore += (0.001f / sec);
        //         }
        //     }
        // }

        #region Public Methods

        public void ResetExpire()
        {
            Expires = DateTime.UtcNow + new TimeSpan(600000000);
        }

        public void AddFlag(PrimFlags flag)
        {
            if ((m_flags & flag) == 0)
            {
                //m_log.Debug("Adding flag: " + ((PrimFlags) flag).ToString());
                m_flags |= flag;

                if (flag == PrimFlags.TemporaryOnRez)
                    ResetExpire();
            }
            // m_log.Debug("Aprev: " + prevflag.ToString() + " curr: " + Flags.ToString());
        }

        public void AddNewParticleSystem(Primitive.ParticleSystem pSystem, bool expire)
        {
            if(expire && pSystem.MaxAge > 0.0001)
                m_particleSystemExpire = Util.GetTimeStamp() + pSystem.MaxAge + 0.1;
            else
                m_particleSystemExpire = -1;
            m_particleSystem = pSystem.GetBytes();
        }

        public void RemoveParticleSystem()
        {
            m_particleSystem = Array.Empty<byte>();
        }

        public void AddTextureAnimation(Primitive.TextureAnimation pTexAnim)
        {
            byte[] data;

            if (pTexAnim.Flags == Primitive.TextureAnimMode.ANIM_OFF)
            {
                data = Utils.EmptyBytes;
            }
            else
            {
                data = new byte[16];

                data[0] = (byte)pTexAnim.Flags;
                data[1] = (byte)pTexAnim.Face;
                data[2] = (byte)pTexAnim.SizeX;
                data[3] = (byte)pTexAnim.SizeY;
                Utils.FloatToBytesSafepos(pTexAnim.Start, data, 4);
                Utils.FloatToBytesSafepos(pTexAnim.Length, data, 8);
                Utils.FloatToBytesSafepos(pTexAnim.Rate, data, 12);
            }
            m_TextureAnimation = data;
        }

        public void AdjustSoundGain(double volume)
        {
            if (volume > 1)
                volume = 1;
            if (volume < 0)
                volume = 0;

            ParentGroup.Scene.ForEachRootClient(delegate(IClientAPI client)
            {
                client.SendAttachedSoundGainChange(UUID, (float)volume);
            });
        }

        /// <summary>
        /// hook to the physics scene to apply impulse
        /// This is sent up to the group, which then finds the root prim
        /// and applies the force on the root prim of the group
        /// </summary>
        /// <param name="impulsei">Vector force</param>
        /// <param name="localGlobalTF">true for the local frame, false for the global frame</param>
        public void ApplyImpulse(Vector3 impulse, bool localGlobalTF)
        {
            if (ParentGroup == null || ParentGroup.IsDeleted || ParentGroup.inTransit)
                return;

            if (localGlobalTF)
                impulse *= GetWorldRotation();

            ParentGroup.applyImpulse(impulse);
        }

        //      SetVelocity for LSL llSetVelocity..  may need revision if having other uses in future
        public void SetVelocity(Vector3 pVel, bool localGlobalTF)
        {
            if (ParentGroup == null || ParentGroup.IsDeleted || ParentGroup.inTransit)
                return;

            if (ParentGroup.IsAttachment)
                return;                         // don't work on attachments (for now ??)

            SceneObjectPart root = ParentGroup.RootPart;

            if (root.VehicleType != (int)Vehicle.TYPE_NONE) // don't mess with vehicles
                return;

            PhysicsActor pa = root.PhysActor;

            if (pa == null || !pa.IsPhysical)
                return;

            if (localGlobalTF)
                pVel *= GetWorldRotation();

            ParentGroup.Velocity = pVel;
        }

        //      SetAngularVelocity for LSL llSetAngularVelocity..  may need revision if having other uses in future
        public void SetAngularVelocity(Vector3 pAngVel, bool localGlobalTF)
        {
            if (ParentGroup == null || ParentGroup.IsDeleted || ParentGroup.inTransit)
                return;

            if (ParentGroup.IsAttachment)
                return;                         // don't work on attachments (for now ??)

            SceneObjectPart root = ParentGroup.RootPart;

            if (root.VehicleType != (int)Vehicle.TYPE_NONE) // don't mess with vehicles
                return;

            PhysicsActor pa = root.PhysActor;

            if (pa == null || !pa.IsPhysical)
                return;

            if (localGlobalTF)
                pAngVel *= GetWorldRotation();

            root.AngularVelocity = pAngVel;
        }


        /// <summary>
        /// hook to the physics scene to apply angular impulse
        /// This is sent up to the group, which then finds the root prim
        /// and applies the force on the root prim of the group
        /// </summary>
        /// <param name="impulsei">Vector force</param>
        /// <param name="localGlobalTF">true for the local frame, false for the global frame</param>
        public void ApplyAngularImpulse(Vector3 impulse, bool localGlobalTF)
        {
           if (ParentGroup == null || ParentGroup.IsDeleted || ParentGroup.inTransit)
                return;

            if (localGlobalTF)
                ParentGroup.ApplyAngularImpulse(impulse * GetWorldRotation());
            else
                ParentGroup.ApplyAngularImpulse(impulse);
        }

        /// <summary>
        /// hook to the physics scene to apply angular impulse
        /// This is sent up to the group, which then finds the root prim
        /// and applies the force on the root prim of the group
        /// </summary>
        /// <param name="impulsei">Vector force</param>
        /// <param name="localGlobalTF">true for the local frame, false for the global frame</param>

        // this is actualy Set Torque.. keeping naming so not to edit lslapi also
        public void SetAngularImpulse(Vector3 torquei, bool localGlobalTF)
        {
            Vector3 torque = torquei;

            if (localGlobalTF)
                torque *= GetWorldRotation();

            Torque = torque;
        }

        /// <summary>
        /// Apply physics to this part.
        /// </summary>
        /// <param name="rootObjectFlags"></param>
        /// <param name="VolumeDetectActive"></param>
        /// <param name="building"></param>

        public void ApplyPhysics(uint _ObjectFlags, bool _VolumeDetectActive, bool building)
        {
            VolumeDetectActive = _VolumeDetectActive;

            if (!ParentGroup.Scene.CollidablePrims)
                return;

            if (PhysicsShapeType == (byte)PhysShapeType.none)
            {
                if(ParentID == 0)
                    m_physicsShapeType = DefaultPhysicsShapeType();
                else
                    return;
            }

            bool isPhysical = (_ObjectFlags & (uint) PrimFlags.Physics) != 0;
            bool isPhantom = (_ObjectFlags & (uint)PrimFlags.Phantom) != 0;

            if (_VolumeDetectActive)
                isPhantom = true;

            if ((!isPhantom || isPhysical || _VolumeDetectActive)
                    && !ParentGroup.IsAttachmentCheckFull()
                    && (Shape.PathCurve != (byte)Extrusion.Flexible))
            {
                AddToPhysics(isPhysical, isPhantom, building, isPhysical);
                UpdatePhysicsSubscribedEvents(); // not sure if appliable here
            }
            else
            {
                PhysActor = null; // just to be sure
                RemFlag(PrimFlags.CameraDecoupled);
            }
        }

        /// <summary>
        /// Duplicates this part.
        /// </summary>
        /// <param name="localID"></param>
        /// <param name="AgentID"></param>
        /// <param name="GroupID"></param>
        /// <param name="linkNum"></param>
        /// <param name="userExposed">True if the duplicate will immediately be in the scene, false otherwise</param>
        /// <returns></returns>
        public SceneObjectPart Copy(uint plocalID, UUID AgentID, UUID GroupID, int linkNum, bool userExposed)
        {
            // FIXME: This is dangerous since it's easy to forget to reset some references when necessary and end up
            // with bugs that only occur in some circumstances (e.g. crossing between regions on the same simulator
            // but not between regions on different simulators).  Really, all copying should be done explicitly.
            SceneObjectPart dupe = (SceneObjectPart)MemberwiseClone();

            dupe.m_shape = m_shape.Copy();
            dupe.m_regionHandle = m_regionHandle;
            if (userExposed)
                dupe.UUID = UUID.Random();

            dupe.m_scriptEvents = new Dictionary<UUID, scriptEvents>();

            dupe.PhysActor = null;

            dupe.OwnerID = AgentID;
            dupe.GroupID = GroupID;
            dupe.GroupPosition = GroupPosition;
            dupe.OffsetPosition = OffsetPosition;
            dupe.RotationOffset = RotationOffset;
            dupe.Velocity = Velocity;
            dupe.Acceleration = Acceleration;
            dupe.AngularVelocity = AngularVelocity;
            dupe.m_flags = m_flags;

            dupe.OwnershipCost = OwnershipCost;
            dupe.ObjectSaleType = ObjectSaleType;
            dupe.SalePrice = SalePrice;
            dupe.Category = Category;
            dupe.m_rezzed = m_rezzed;

            dupe.m_UndoRedo = null;
            dupe.m_isSelected = false;

            dupe.IgnoreUndoUpdate = false;
            dupe.Undoing = false;

            dupe.m_inventory = new SceneObjectPartInventory(dupe);
            dupe.m_inventory.Items = (TaskInventoryDictionary)m_inventory.Items.Clone();

            if (userExposed)
            {
                dupe.ResetIDs(linkNum);
                dupe.m_inventory.HasInventoryChanged = true;
            }
            else
            {
                dupe.m_inventory.HasInventoryChanged = m_inventory.HasInventoryChanged;
            }

            // Move afterwards ResetIDs as it clears the localID
            dupe.LocalId = plocalID;

            // This may be wrong...    it might have to be applied in SceneObjectGroup to the object that's being duplicated.
            if(OwnerID.NotEqual(GroupID))
                dupe.LastOwnerID = OwnerID;
            else
                dupe.LastOwnerID = LastOwnerID; // redundant ?

            dupe.RezzerID = RezzerID;

            byte[] oldextrap = Shape.ExtraParams;
            byte[] extraP = new byte[oldextrap.Length];
            Array.Copy(oldextrap, extraP, extraP.Length);
            dupe.Shape.ExtraParams = extraP;
            if(Shape.RenderMaterials is not null && Shape.RenderMaterials.overrides is not null && 
                Shape.RenderMaterials.overrides.Length > 0)
            {              
                dupe.Shape.RenderMaterials.overrides = new Primitive.RenderMaterials.RenderMaterialOverrideEntry[Shape.RenderMaterials.overrides.Length];
                Shape.RenderMaterials.overrides.CopyTo(dupe.Shape.RenderMaterials.overrides,0);
            }

            dupe.m_sittingAvatars = new HashSet<ScenePresence>();
            dupe.SitTargetAvatar = UUID.Zero;
            // safeguard  actual copy is done in sog.copy
            dupe.KeyframeMotion = null;
            dupe.PayPrice = (int[])PayPrice.Clone();

            if(DynAttrs != null)
                dupe.DynAttrs.CopyFrom(DynAttrs);

            if (userExposed)
            {
                bool UsePhysics = ((dupe.m_flags & PrimFlags.Physics) != 0);
                dupe.DoPhysicsPropertyUpdate(UsePhysics, true);
            }

            if (dupe.PhysActor != null)
                dupe.PhysActor.LocalID = plocalID;

            dupe.PseudoCRC = (int)(DateTime.UtcNow.Ticks);

            ParentGroup.Scene.EventManager.TriggerOnSceneObjectPartCopy(dupe, this, userExposed);

            //m_log.DebugFormat("[SCENE OBJECT PART]: Clone of {0} {1} finished", Name, UUID);

            return dupe;
        }

        /// <summary>
        /// Do a physics propery update for this part.
        /// now also updates phantom and volume detector
        /// </summary>
        /// <param name="UsePhysics"></param>
        /// <param name="isNew"></param>
        public void DoPhysicsPropertyUpdate(bool UsePhysics, bool isNew)
        {
            if (ParentGroup.Scene == null)
                return;

            if (!ParentGroup.Scene.PhysicalPrims && UsePhysics)
                return;

            PhysicsActor pa = PhysActor;

            if (pa != null)
            {
                if (UsePhysics != pa.IsPhysical)
                    ClampScale(UsePhysics);

                if (UsePhysics != pa.IsPhysical || isNew)
                {
                    if (pa.IsPhysical) // implies UsePhysics==false for this block
                    {
                        if (!isNew)  // implies UsePhysics==false for this block
                        {
                            ParentGroup.Scene.RemovePhysicalPrim(1);

                            Stop();

                            if (pa.Phantom && !VolumeDetectActive)
                            {
                                RemoveFromPhysics();
                                return;
                            }

                            pa.IsPhysical = UsePhysics;
                            pa.OnRequestTerseUpdate -= PhysicsRequestingTerseUpdate;
                            pa.OnOutOfBounds -= PhysicsOutOfBounds;
                            pa.delink();
                        }
                    }

                    if (pa.IsPhysical != UsePhysics)
                        pa.IsPhysical = UsePhysics;

                    if (UsePhysics)
                    {
                        ParentGroup.RootPart.KeyframeMotion?.Stop();
                        ParentGroup.RootPart.KeyframeMotion = null;
                        ParentGroup.Scene.AddPhysicalPrim(1);

                        PhysActor.OnRequestTerseUpdate += PhysicsRequestingTerseUpdate;
                        PhysActor.OnOutOfBounds += PhysicsOutOfBounds;

                        if (_parentID != 0 && _parentID != LocalId)
                        {
                            PhysicsActor parentPa = ParentGroup.RootPart.PhysActor;

                            if (parentPa != null)
                            {
                                pa.link(parentPa);
                            }
                        }
                    }
                }

                bool phan = ((m_flags & PrimFlags.Phantom) != 0);
                if (pa.Phantom != phan)
                    pa.Phantom = phan;

                // some engines dont' have this check still
                // if (VolumeDetectActive != pa.IsVolumeDtc)
                {
                    if (VolumeDetectActive)
                        pa.SetVolumeDetect(1);
                    else
                        pa.SetVolumeDetect(0);
                }
            }
        }

        /// <summary>
        /// Restore this part from the serialized xml representation.
        /// </summary>
        /// <param name="xmlReader"></param>
        /// <returns></returns>
        public static SceneObjectPart FromXml(XmlReader xmlReader)
        {
            SceneObjectPart part = SceneObjectSerializer.Xml2ToSOP(xmlReader);

            // for tempOnRez objects, we have to fix the Expire date.
            if ((part.m_flags & PrimFlags.TemporaryOnRez) != 0)
                part.ResetExpire();

            return part;
        }

        public bool GetDieAtEdge()
        {
            if (ParentGroup.IsDeleted)
                return false;

            return ParentGroup.RootPart.DIE_AT_EDGE;
        }

        public bool GetReturnAtEdge()
        {
            if (ParentGroup.IsDeleted)
                return false;

            return ParentGroup.RootPart.RETURN_AT_EDGE;
        }

        public void SetReturnAtEdge(bool p)
        {
            if (ParentGroup.IsDeleted)
                return;

            ParentGroup.RootPart.RETURN_AT_EDGE = p;
        }

        public void SetStatusSandbox(bool p)
        {
            if (ParentGroup.IsDeleted)
                return;
            StatusSandboxPos = ParentGroup.RootPart.AbsolutePosition;
            ParentGroup.RootPart.StatusSandbox = p;
        }

        public bool GetStatusSandbox()
        {
            if (ParentGroup.IsDeleted)
                return false;

            return ParentGroup.RootPart.StatusSandbox;
        }

        public int GetAxisRotation(int axis)
        {
           if (!ParentGroup.IsDeleted)
                return ParentGroup.GetAxisRotation(axis);

            return 0;
        }

        public uint GetEffectiveObjectFlags()
        {
            uint eff = (uint)(m_flags | m_localFlags);
            if(m_inventory == null || m_inventory.Count == 0)
                eff |= (uint)PrimFlags.InventoryEmpty;
            return eff;
        }

        // some of this lines need be moved to other place later

        // effective permitions considering only this part inventory contents perms
        public uint AggregatedInnerOwnerPerms {get; private set; }
        public uint AggregatedInnerGroupPerms {get; private set; }
        public uint AggregatedInnerEveryonePerms {get; private set; }
        private readonly object InnerPermsLock = new object();

        public void AggregateInnerPerms()
        {
            // assuming child prims permissions masks are irrelevant on a linkset
            // root part is handle at SOG since its masks are the sog masks
            const uint mask = (uint)PermissionMask.AllEffective;

            uint owner = mask;
            uint group = mask;
            uint everyone = mask;

            lock(InnerPermsLock) // do we really need this?
            {
                Inventory?.AggregateInnerPerms(ref owner, ref group, ref everyone);
            
                AggregatedInnerOwnerPerms = owner & mask;
                AggregatedInnerGroupPerms = group & mask;
                AggregatedInnerEveryonePerms = everyone & mask;
            }
            ParentGroup?.InvalidateEffectivePerms();
        }

        // same as above but called during group Effective Permission validation
        public void AggregatedInnerPermsForGroup()
        {
            // assuming child prims permissions masks are irrelevant on a linkset
            // root part is handle at SOG since its masks are the sog masks
            const uint mask = (uint)PermissionMask.AllEffective;

            uint owner = mask;
            uint group = mask;
            uint everyone = mask;

            lock(InnerPermsLock) // do we really need this?
            {
                Inventory?.AggregateInnerPerms(ref owner, ref group, ref everyone);
            
                AggregatedInnerOwnerPerms = owner & mask;
                AggregatedInnerGroupPerms = group & mask;
                AggregatedInnerEveryonePerms = everyone & mask;
            }
        }

        public Vector3 GetGeometricCenter()
        {
            // this is not real geometric center but a average of positions relative to root prim acording to
            // http://wiki.secondlife.com/wiki/llGetGeometricCenter
            // ignoring tortured prims details since sl also seems to ignore
            // so no real use in doing it on physics
            return ParentGroup.IsDeleted ? Vector3.Zero : ParentGroup.GetGeometricCenter();
        }

        public float GetMass()
        {
            PhysicsActor pa = PhysActor;
            return pa is null ? 0 : pa.Mass;
        }

        public Vector3 GetCenterOfMass()
        {
            if (ParentGroup.RootPart == this)
                return ParentGroup.IsDeleted ? AbsolutePosition : ParentGroup.GetCenterOfMass();

            PhysicsActor pa = PhysActor;
            return (pa is null) ? AbsolutePosition : pa.CenterOfMass;
        }

        public Vector3 GetPartCenterOfMass()
        {
            PhysicsActor pa = PhysActor;
            return pa is null ? AbsolutePosition : pa.CenterOfMass;
        }


        public Vector3 GetForce()
        {
            return Force;
        }

        /// <summary>
        /// Method for a prim to get it's world position from the group.
        /// </summary>
        /// <remarks>
        /// Remember, the Group Position simply gives the position of the group itself
        /// </remarks>
        /// <returns>A Linked Child Prim objects position in world</returns>
        public Vector3 GetWorldPosition()
        {
            // If a child SOP, my position is relative to the root SOP so take
            //    my info and add the root's position and rotation to
            //    get my world position.
            return _parentID == 0 ? GroupPosition : ParentGroup.AbsolutePosition + OffsetPosition * ParentGroup.RootPart.RotationOffset;
        }

        /// <summary>
        /// Gets the rotation of this prim offset by the group rotation
        /// </summary>
        /// <returns></returns>
        public Quaternion GetWorldRotation()
        {
            // A child SOP's rotation is relative to the root SOP's rotation.
            // Combine them to get my absolute rotation.
            return _parentID == 0 ? RotationOffset : ParentGroup.RootPart.RotationOffset * RotationOffset;
        }

        /// <summary>
        /// Uses a PID to attempt to clamp the object on the Z axis at the given height over tau seconds.
        /// </summary>
        /// <param name="height">Height to hover.  Height of zero disables hover.</param>
        /// <param name="hoverType">Determines what the height is relative to </param>
        /// <param name="tau">Number of seconds over which to reach target</param>
        public void SetHoverHeight(float height, PIDHoverType hoverType, float tau)
        {
            ParentGroup.SetHoverHeight(height, hoverType, tau);
        }

        public void StopHover()
        {
            ParentGroup.SetHoverHeight(0f, PIDHoverType.Ground, 0f);
        }

        public virtual void OnGrab(Vector3 offsetPos, IClientAPI remoteClient)
        {
        }

        public void SetCollisionFilter(bool access, string name, string id)
        {
            if(string.IsNullOrEmpty(id))
            {
                if (string.IsNullOrEmpty(name))
                {
                    m_CollisionFilterString = string.Empty;
                    m_CollisionFilterType = access ? 0 : -1;
                }
                else
                {
                    m_CollisionFilterString = name;
                    m_CollisionFilterType = access ? 11 : 1;
                }
            }
            else
            {
                if (string.IsNullOrEmpty(name))
                {
                    m_CollisionFilterString = id;
                    m_CollisionFilterType = access ? 12 : 2;
                }
                else
                {
                    m_CollisionFilterString = name + id;
                    m_CollisionFilterType = access ? 13 : 3;
                }
            }
        }

        public void ClearCollisionFilter()
        {
            m_CollisionFilterType = 0;
            m_CollisionFilterString = string.Empty;
        }

        public bool CollisionFilteredOut(UUID objectID, string objectName)
        {
            return m_CollisionFilterType switch
            {
                // not set
                0 => false,
                // disable all
                -1 => true,
                // false by name
                1 => m_CollisionFilterString.Equals(objectName, StringComparison.InvariantCultureIgnoreCase),
                // false by id 
                2 => m_CollisionFilterString.Equals(objectID.ToString(), StringComparison.InvariantCultureIgnoreCase),
                // false by name and id 
                3 => m_CollisionFilterString.Equals(objectName + objectID.ToString(), StringComparison.InvariantCultureIgnoreCase),
                // true by name
                11 => !m_CollisionFilterString.Equals(objectName, StringComparison.InvariantCultureIgnoreCase),
                // true by id
                12 => !m_CollisionFilterString.Equals(objectID.ToString(), StringComparison.InvariantCultureIgnoreCase),
                // true by name and id
                13 => !m_CollisionFilterString.Equals(objectName + objectID.ToString(), StringComparison.InvariantCultureIgnoreCase),
                _ => false,
            };
        }

        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]
        private DetectedObject CreateDetObject(SceneObjectPart obj)
        {
            return new DetectedObject()
            {
                keyUUID = obj.UUID,
                nameStr = obj.Name,
                ownerUUID = obj.OwnerID,
                posVector = obj.AbsolutePosition,
                rotQuat = obj.GetWorldRotation(),
                velVector = obj.Velocity,
                colliderType = 0,
                groupUUID = obj.GroupID,
                linkNumber = LinkNum
            };
        }

        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]
        private DetectedObject CreateDetObject(ScenePresence av)
        {
            DetectedObject detobj = new DetectedObject()
            {
                keyUUID = av.UUID,
                nameStr = av.ControllingClient.Name,
                ownerUUID = av.UUID,
                posVector = av.AbsolutePosition,
                rotQuat = av.Rotation,
                velVector = av.Velocity,
                colliderType = av.IsNPC ? 0x20 : 0x1, // OpenSim\Region\ScriptEngine\Shared\Helpers.cs
                groupUUID = av.ControllingClient.ActiveGroupId,
                linkNumber = LinkNum
            };
            if(av.IsSatOnObject)
                detobj.colliderType |= 0x4; //passive
            else if(!detobj.velVector.IsZero())
                detobj.colliderType |= 0x2; //active
            return detobj;
        }

        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]
        private DetectedObject CreateDetObjectForGround()
        {
            return new DetectedObject()
            {
                keyUUID = UUID.Zero,
                nameStr = "",
                ownerUUID = UUID.Zero,
                posVector = ParentGroup.RootPart.AbsolutePosition,
                rotQuat = Quaternion.Identity,
                velVector = Vector3.Zero,
                colliderType = 0,
                groupUUID = UUID.Zero,
                linkNumber = LinkNum
            };
        }

        private ColliderArgs CreateColliderArgs(SceneObjectPart dest, List<uint> colliders)
        {
            ColliderArgs colliderArgs = new ColliderArgs();
            List<DetectedObject> colliding = new List<DetectedObject>();
            Scene parentScene = ParentGroup.Scene;
            foreach (uint localId in colliders)
            {
                if (localId == 0)
                    continue;

                SceneObjectPart obj = parentScene.GetSceneObjectPart(localId);
                if (obj != null)
                {
                    if (!dest.CollisionFilteredOut(obj.UUID, obj.Name))
                        colliding.Add(CreateDetObject(obj));
                }
                else
                {
                    ScenePresence av = parentScene.GetScenePresence(localId);
                    if (av != null && (!av.IsChildAgent))
                    {
                        if (!dest.CollisionFilteredOut(av.UUID, av.Name))
                            colliding.Add(CreateDetObject(av));
                    }
                }
            }

            colliderArgs.Colliders = colliding;

            return colliderArgs;
        }

        private delegate void ScriptCollidingNotification(uint localID, ColliderArgs message);

        private void SendCollisionEvent(scriptEvents ev, List<uint> colliders, ScriptCollidingNotification notify)
        {
            if (colliders.Count > 0)
            {
                ColliderArgs CollidingMessage;
                if ((ScriptEvents & ev) != 0)
                {
                    CollidingMessage = CreateColliderArgs(this, colliders);
                    if (CollidingMessage.Colliders.Count > 0)
                        notify(LocalId, CollidingMessage);

                    if (!PassCollisions)
                        return;
                }

                SceneObjectPart root = ParentGroup.RootPart;
                uint rootID = root.LocalId;
                if (rootID != LocalId && (root.ScriptEvents & ev) != 0)
                {
                    CollidingMessage = CreateColliderArgs(root, colliders);
                    if (CollidingMessage.Colliders.Count > 0)
                        notify(rootID, CollidingMessage);
                }
            }
        }

        private void SendLandCollisionEvent(scriptEvents ev, ScriptCollidingNotification notify)
        {
            ColliderArgs LandCollidingMessage = new ColliderArgs();
            LandCollidingMessage.Colliders = new List<DetectedObject>()
            {
                CreateDetObjectForGround()
            };

            if ((ScriptEvents & ev) != 0)
            {
                notify(LocalId, LandCollidingMessage);
                if(!PassCollisions)
                    return;
            }
            SceneObjectPart root = ParentGroup.RootPart;
            if(LocalId != root.LocalId && (root.ScriptEvents & ev) != 0)
                notify(ParentGroup.RootPart.LocalId, LandCollidingMessage);
        }

        public void PhysicsCollision(EventArgs e)
        {
            if (ParentGroup.Scene == null || ParentGroup.IsDeleted || ParentGroup.inTransit)
                return;

            CollisionEventUpdate a = (CollisionEventUpdate)e;
            Dictionary<uint, ContactPoint> collissionswith = a.m_objCollisionList;
            EventManager eventManager;
            scriptEvents combinedEvents = ScriptEvents | ParentGroup.RootPart.ScriptEvents;

            int ncollisions = collissionswith.Count;
            if (ncollisions == 0)
            {
                if (m_lastColliders.Count == 0 && !m_lastLandCollide)
                    return; // nothing to do

                eventManager = ParentGroup.Scene.EventManager;
                combinedEvents = ScriptEvents | ParentGroup.RootPart.ScriptEvents;

                if (m_lastColliders.Count > 0 && (combinedEvents & scriptEvents.collision_end) != 0)
                    SendCollisionEvent(scriptEvents.collision_end, m_lastColliders, eventManager.TriggerScriptCollidingEnd);

                if (m_lastLandCollide && !VolumeDetectActive && (combinedEvents & scriptEvents.land_collision_end) != 0)
                    SendLandCollisionEvent(scriptEvents.land_collision_end, eventManager.TriggerScriptLandCollidingEnd);

                m_lastColliders.Clear();
                m_lastLandCollide = false;
                return;
            }

            bool thisHitLand = false;
            bool startLand = false;

            List<uint> thisHitColliders = new List<uint>(ncollisions);
            List<uint> endedColliders = new List<uint>(m_lastColliders.Count);
            List<uint> startedColliders = new List<uint>(ncollisions);

            // calculate things that started colliding this time
            // and build up list of colliders this time
            if (!VolumeDetectActive && CollisionSoundType >= 0)
            {
                List<CollisionForSoundInfo> soundinfolist = new List<CollisionForSoundInfo>();
                CollisionForSoundInfo soundinfo;
                ContactPoint curcontact;

                foreach (uint id in collissionswith.Keys)
                {
                    if(id == 0)
                    {
                        thisHitLand = true;
                        startLand = !m_lastLandCollide;
                        if (startLand)
                        {
                            curcontact = collissionswith[id];
                            if (Math.Abs(curcontact.RelativeSpeed) > 0.2)
                            {
                                soundinfo = new CollisionForSoundInfo()
                                {
                                    colliderID = id,
                                    position = curcontact.Position,
                                    relativeVel = curcontact.RelativeSpeed
                                };
                                soundinfolist.Add(soundinfo);
                            }
                        }
                    }
                    else
                    {
                        thisHitColliders.Add(id);
                        if (!m_lastColliders.Contains(id))
                        {
                            startedColliders.Add(id);

                            curcontact = collissionswith[id];
                            if (Math.Abs(curcontact.RelativeSpeed) > 0.2)
                            {
                                soundinfo = new CollisionForSoundInfo()
                                {
                                    colliderID = id,
                                    position = curcontact.Position,
                                    relativeVel = curcontact.RelativeSpeed
                                };
                                soundinfolist.Add(soundinfo);
                            }
                        }
                    }
                }
                // play sounds.
                if (soundinfolist.Count > 0)
                    CollisionSounds.PartCollisionSound(this, soundinfolist);
            }
            else
            {
                foreach (uint id in collissionswith.Keys)
                {
                    if(id == 0)
                    {
                        thisHitLand = true;
                        startLand = !m_lastLandCollide;
                    }
                    else
                    {
                        thisHitColliders.Add(id);
                        if (!m_lastColliders.Contains(id))
                            startedColliders.Add(id);
                    }
                }
            }

            // calculate things that ended colliding
            foreach (uint localID in m_lastColliders)
            {
                if (!thisHitColliders.Contains(localID))
                    endedColliders.Add(localID);
            }

            eventManager = ParentGroup.Scene.EventManager;
            combinedEvents = ScriptEvents | ParentGroup.RootPart.ScriptEvents;
            if ((combinedEvents & scriptEvents.anyobjcollision) != 0)
            {
                if ((combinedEvents & scriptEvents.collision_start) != 0)
                    SendCollisionEvent(scriptEvents.collision_start, startedColliders, eventManager.TriggerScriptCollidingStart);
                if ((combinedEvents & scriptEvents.collision_end) != 0)
                    SendCollisionEvent(scriptEvents.collision_end  , endedColliders  , eventManager.TriggerScriptCollidingEnd);
            }

            if (!VolumeDetectActive)
            {
                if ((combinedEvents & scriptEvents.collision) != 0)
                    SendCollisionEvent(scriptEvents.collision, m_lastColliders, eventManager.TriggerScriptColliding);

                if ((combinedEvents & scriptEvents.anylandcollision) != 0)
                {
                    if (thisHitLand)
                    {
                        if (startLand && (combinedEvents & scriptEvents.land_collision_start) != 0)
                            SendLandCollisionEvent(scriptEvents.land_collision_start, eventManager.TriggerScriptLandCollidingStart);
                        if ((combinedEvents & scriptEvents.land_collision) != 0)
                            SendLandCollisionEvent(scriptEvents.land_collision, eventManager.TriggerScriptLandColliding);
                    }
                    else if(m_lastLandCollide && (combinedEvents & scriptEvents.land_collision_end) != 0)
                        SendLandCollisionEvent(scriptEvents.land_collision_end, eventManager.TriggerScriptLandCollidingEnd);
                }
            }

            m_lastColliders = thisHitColliders;
            m_lastLandCollide = thisHitLand;
        }

        // The Collision sounds code calls this
        public void SendCollisionSound(UUID soundID, double volume, Vector3 position)
        {
            if (soundID.IsZero())
                return;

            int now = Util.EnvironmentTickCount();
            if (Util.EnvironmentTickCountSubtract(now, LastColSoundSentTime) < 200)
                return;

            ISoundModule soundModule = ParentGroup.Scene.RequestModuleInterface<ISoundModule>();
            if (soundModule == null)
                return;

            if (volume > 1)
                volume = 1;
            else if (volume < 0)
                volume = 0;

            LastColSoundSentTime = now;

            UUID ownerID = OwnerID;
            UUID objectID = ParentGroup.RootPart.UUID;
            UUID parentID = ParentGroup.UUID;
            ulong regionHandle = ParentGroup.Scene.RegionInfo.RegionHandle;

            soundModule.TriggerCollisionSound(soundID, ownerID, objectID, parentID, volume, position, regionHandle);
        }

        public void PhysicsOutOfBounds(Vector3 pos)
        {
            // Note: This is only being called on the root prim at this time.

            m_log.ErrorFormat(
                "[SCENE OBJECT PART]: Physical object {0}, localID {1} went out of bounds at {2} in {3}.  Stopping at {4} and making non-physical.",
                Name, LocalId, pos, ParentGroup.Scene.Name, AbsolutePosition);

            RemFlag(PrimFlags.Physics);
            DoPhysicsPropertyUpdate(false, true);
        }

        public void PhysicsRequestingTerseUpdate()
        {
            PhysicsActor pa = PhysActor;

            if (pa != null)
            {
                Vector3 newpos = pa.Position;
                if (!ParentGroup.Scene.PositionIsInCurrentRegion(newpos))
                {
                    // Setting position outside current region will start region crossing
                    ParentGroup.AbsolutePosition = newpos;
                    return;
                }
                //ParentGroup.RootPart.m_groupPosition = newpos;
            }

            ScheduleTerseUpdate();
        }

        public void RemFlag(PrimFlags flag)
        {
            m_flags &= ~flag;
        }

        public void RemoveScriptEvents(UUID scriptid)
        {
            lock (m_scriptEvents)
            {
                if (m_scriptEvents.TryGetValue(scriptid, out scriptEvents ev))
                {
                    if((ev & (scriptEvents.anyTarget)) != 0 && ParentGroup != null)
                            ParentGroup.RemoveScriptTargets(scriptid);
                    if ((AggregatedScriptEvents & scriptEvents.email) != 0)
                    {
                        IEmailModule scriptEmail = ParentGroup.Scene.RequestModuleInterface<IEmailModule>();
                        scriptEmail?.RemovePartMailBox(UUID);
                    }
                    m_scriptEvents.Remove(scriptid);
                    aggregateScriptEvents();
                }
            }
        }

        public void RemoveScriptTargets(UUID scriptid)
        {
            ParentGroup?.RemoveScriptTargets(scriptid);
        }

        /// <summary>
        /// Reset UUIDs for this part.  This involves generate this part's own UUID and
        /// generating new UUIDs for all the items in the inventory.
        /// </summary>
        /// <param name="linkNum">Link number for the part</param>
        public void ResetIDs(int linkNum)
        {
            UUID = UUID.Random();
            LinkNum = linkNum;
            LocalId = 0;
            Inventory.ResetInventoryIDs();
            ++PseudoCRC;
        }


        private void ClampScale(bool isPhysical)
        {
            float minsize = isPhysical ? ParentGroup.Scene.m_minPhys : ParentGroup.Scene.m_minNonphys;
            float maxsize = isPhysical ? ParentGroup.Scene.m_maxPhys : ParentGroup.Scene.m_maxNonphys;
            Vector3 scale = Scale;
            bool changed = false;

            if (scale.X < minsize)
            {
                scale.X = minsize;
                changed = true;
            }
            else if (scale.X > maxsize)
            {
                scale.X = maxsize;
                changed = true;
            }

            if (scale.Y < minsize)
            {
                scale.Y = minsize;
                changed = true;
            }
            else if (scale.Y > maxsize)
            {
                scale.Y = maxsize;
                changed = true;
            }

            if (scale.Z < minsize)
            {
                scale.Z = minsize;
                changed = true;
            }
            else if (scale.Z > maxsize)
            {
                scale.Z = maxsize;
                changed = true;
            }

            if (changed)
                Scale = scale;
        }

        /// <summary>
        /// Set the scale of this part.
        /// </summary>
        /// <remarks>
        /// Unlike the scale property, this checks the new size against scene limits and schedules a full property
        /// update to viewers.
        /// </remarks>
        /// <param name="scale"></param>
        public void Resize(Vector3 scale)
        {
            PhysicsActor pa = PhysActor;

            if (ParentGroup.Scene != null)
            {
                float minsize = ParentGroup.Scene.m_minNonphys;
                float maxsize = ParentGroup.Scene.m_maxNonphys;
                if (pa != null && pa.IsPhysical)
                    {
                    minsize = ParentGroup.Scene.m_minPhys;
                    maxsize = ParentGroup.Scene.m_maxPhys;
                    }
                scale.X = Utils.Clamp(scale.X, minsize, maxsize);
                scale.Y = Utils.Clamp(scale.Y, minsize, maxsize);
                scale.Z = Utils.Clamp(scale.Z, minsize, maxsize);
            }
//            m_log.DebugFormat("[SCENE OBJECT PART]: Resizing {0} {1} to {2}", Name, LocalId, scale);

            Scale = scale;

            ParentGroup.HasGroupChanged = true;
            ScheduleFullUpdate();
        }

        public void RotLookAt(Quaternion target, float strength, float damping)
        {
            if(ParentGroup.IsDeleted)
                return;

            // for now we only handle physics case
            if(!ParentGroup.UsesPhysics || ParentGroup.IsAttachment)
                return;

            // physical is SOG
            if(ParentGroup.RootPart != this)
            {
                ParentGroup.RotLookAt(target, strength, damping);
                return;
            }

            APIDDamp = damping;
            APIDStrength = strength;
            APIDTarget = target;

            if (APIDStrength <= 0)
            {
                m_log.WarnFormat("[SceneObjectPart] Invalid rotation strength {0}",APIDStrength);
                return;
            }

            APIDActive = true;

            // Necessary to get the lookat deltas applied
            ParentGroup.QueueForUpdateCheck();
        }

        public void StartLookAt(Quaternion target, float strength, float damping)
        {
            if(ParentGroup.IsDeleted)
                return;

            // non physical is done on LSL
            if(ParentGroup.IsAttachment || !ParentGroup.UsesPhysics)
                return;

            // physical is SOG
            if(ParentGroup.RootPart != this)
                ParentGroup.RotLookAt(target, strength, damping);
            else
                RotLookAt(target,strength,damping);
        }

        public void StopLookAt()
        {
            if(ParentGroup.IsDeleted)
                return;

            if(ParentGroup.RootPart != this && ParentGroup.UsesPhysics)
                 ParentGroup.StopLookAt();

            // just in case do this always
            if(APIDActive)
                AngularVelocity = Vector3.Zero;

            APIDActive = false;
        }

        /// <summary>
        /// Schedules this prim for a full update
        /// </summary>
        public void ScheduleFullUpdate()
        {
            if (ParentGroup == null || ParentGroup.IsDeleted || ParentGroup.Scene == null)
                return;

            ++PseudoCRC;
            if (ParentGroup.Scene.GetNumberOfClients() == 0)
                return;

            ParentGroup.QueueForUpdateCheck(); // just in case

            lock(UpdateFlagLock)
                UpdateFlag |= PrimUpdateFlags.FullUpdate;

            ParentGroup.Scene.EventManager.TriggerSceneObjectPartUpdated(this, true);
        }

        public void ScheduleFullAnimUpdate()
        {
            if (ParentGroup == null || ParentGroup.IsDeleted || ParentGroup.Scene == null)
                return;

            ++PseudoCRC;

            if (ParentGroup.Scene.GetNumberOfClients() == 0)
                return;

            PrimUpdateFlags update = PrimUpdateFlags.FullUpdatewithAnim;
            if (Animations == null || !ParentGroup.RootPart.Shape.MeshFlagEntry)
                update = PrimUpdateFlags.FullUpdate;

            ParentGroup.QueueForUpdateCheck(); // just in case

            lock (UpdateFlagLock)
                UpdateFlag |= update;

            ParentGroup.Scene.EventManager.TriggerSceneObjectPartUpdated(this, true);
        }

        /// <summary>
        /// Schedule a terse update for this prim.  Terse updates only send position,
        /// rotation, velocity and rotational velocity information.
        /// </summary>
        public void ScheduleTerseUpdate()
        {
            if (ParentGroup == null || ParentGroup.IsDeleted || ParentGroup.Scene == null)
                return;

            ++PseudoCRC;
            ParentGroup.HasGroupChanged = true;

            if(ParentGroup.Scene.GetNumberOfClients() == 0)
                return;

            ParentGroup.QueueForUpdateCheck();

            bool isfull = false;
            PrimUpdateFlags update;
            if (ParentGroup.IsAttachment)
            {
                update = PrimUpdateFlags.FullUpdate;
                isfull = true;
            }
            else
                update = PrimUpdateFlags.TerseUpdate;

            lock (UpdateFlagLock)
                UpdateFlag |= update;

            ParentGroup.Scene.EventManager.TriggerSceneObjectPartUpdated(this, isfull);
        }

        public void ScheduleUpdate(PrimUpdateFlags update)
        {
            if (ParentGroup is null || ParentGroup.IsDeleted)
                return;

            if (Animations is null)
                update &= ~PrimUpdateFlags.Animations;
            if (Shape is null || Shape.RenderMaterials is null)
                update &= ~PrimUpdateFlags.MaterialOvr;

            if (update == PrimUpdateFlags.None)
                return;

            ++PseudoCRC;
            ParentGroup.HasGroupChanged = true;

            if (ParentGroup.Scene.GetNumberOfClients() == 0)
                return;

            bool isfull;
            if (ParentGroup.IsAttachment)
            {
                update |= PrimUpdateFlags.FullUpdate;
                isfull = true;
            }
            else
                isfull = (update & PrimUpdateFlags.FullUpdate) == PrimUpdateFlags.FullUpdate;

            lock (UpdateFlagLock)
                UpdateFlag |= update;

            ParentGroup.QueueForUpdateCheck();

            ParentGroup.Scene.EventManager.TriggerSceneObjectPartUpdated(this, isfull);
        }

        public void ScriptSetPhysicsStatus(bool UsePhysics)
        {
            ParentGroup.ScriptSetPhysicsStatus(UsePhysics);
        }

        /// <summary>
        /// Send a full update to the client for the given part
        /// </summary>
        /// <param name="remoteClient"></param>
        protected internal void SendFullUpdate(IClientAPI remoteClient)
        {
            if (ParentGroup == null)
                return;

            if (ParentGroup.IsAttachment)
            {
                ScenePresence sp = ParentGroup.Scene.GetScenePresence(ParentGroup.AttachedAvatar);
                sp?.SendAttachmentUpdate(this, PrimUpdateFlags.FullUpdate);
            }
            else
            {
                SendUpdateToClient(remoteClient, PrimUpdateFlags.FullUpdate);
            }
        }

        protected internal void SendUpdate(IClientAPI remoteClient, PrimUpdateFlags update)
        {
            if (ParentGroup == null)
                return;

            if (ParentGroup.IsAttachment)
            {
                ScenePresence sp = ParentGroup.Scene.GetScenePresence(ParentGroup.AttachedAvatar);
                sp?.SendAttachmentUpdate(this, update);
            }
            else
            {
                SendUpdateToClient(remoteClient, update);
            }
        }

        /// <summary>
        /// Send a full update for this part to all clients.
        /// </summary>
        public void SendFullUpdateToAllClientsNoAttachment()
        {
            if (ParentGroup == null)
                return;

            ++PseudoCRC;
            // Update the "last" values
            lock (UpdateFlagLock)
            {
                m_lastPosition = AbsolutePosition;
                m_lastRotation = RotationOffset;
                m_lastVelocity = Velocity;
                m_lastAcceleration = Acceleration;
                m_lastAngularVelocity = AngularVelocity;
                m_lastUpdateSentTime = Util.GetTimeStampMS();
                UpdateFlag &= ~PrimUpdateFlags.FullUpdate;
            }

            ParentGroup.Scene.ForEachScenePresence(delegate(ScenePresence avatar)
            {
                SendUpdateToClient(avatar.ControllingClient, PrimUpdateFlags.FullUpdate);
            });
        }

        public void SendFullUpdateToAllClients()
        {
            if (ParentGroup == null)
                return;

            ++PseudoCRC;
            // Update the "last" values
            lock (UpdateFlagLock)
            {
                m_lastPosition = AbsolutePosition;
                m_lastRotation = RotationOffset;
                m_lastVelocity = Velocity;
                m_lastAcceleration = Acceleration;
                m_lastAngularVelocity = AngularVelocity;
                m_lastUpdateSentTime = Util.GetTimeStampMS();
                UpdateFlag &= ~PrimUpdateFlags.FullUpdate;
            }

            if (ParentGroup.IsAttachment)
            {
                ScenePresence sp = ParentGroup.Scene.GetScenePresence(ParentGroup.AttachedAvatar);
                sp?.SendAttachmentUpdate(this, PrimUpdateFlags.FullUpdate);
            }
            else
            {
                ParentGroup.Scene.ForEachScenePresence(delegate(ScenePresence avatar)
                {
                    SendUpdateToClient(avatar.ControllingClient, PrimUpdateFlags.FullUpdate);
                });
            }
        }

        private const float ROTATION_TOLERANCE = 0.002f;
        private const float VELOCITY_TOLERANCE = 0.1f;
        private const float ANGVELOCITY_TOLERANCE = 0.002f;
        private const float POSITION_TOLERANCE = 0.05f; // I don't like this, but I suppose it's necessary
        private const double TIME_MS_TOLERANCE = 250.0; //llSetPos has a 200ms delay. This should NOT be 3 seconds.

        private static Vector3 ClampVectorForTerseUpdate(Vector3 v, float max)
        {
            float a, b;

            a = Math.Abs(v.X);
            b = Math.Abs(v.Y);
            if (b > a)
                a = b;
            b = Math.Abs(v.Z);
            if (b > a)
                a = b;

            if (a > max)
            {
                a = max / a;
                v.X *= a;
                v.Y *= a;
                v.Z *= a;
            }
            return v;
        }

        /// <summary>
        /// Tell all the prims which have had updates scheduled
        /// </summary>
        public void SendScheduledUpdates(double now)
        {  
            PrimUpdateFlags current;
            lock (UpdateFlagLock) 
            {
                current = UpdateFlag;

                if (current == PrimUpdateFlags.None)
                    return;

                if(current == PrimUpdateFlags.TerseUpdate)
                {
                    while(true) // just to avoid ugly goto
                    {
                        double elapsed = now - m_lastUpdateSentTime;
                        if (elapsed > TIME_MS_TOLERANCE)
                            break;

                        if ( !Acceleration.ApproxEquals(m_lastAcceleration, VELOCITY_TOLERANCE))
                            break;

                        Vector3 curvel = ClampVectorForTerseUpdate(Velocity, 128f);
                        Vector3 tmp = ClampVectorForTerseUpdate(m_lastVelocity, 128f);
                        if (!curvel.ApproxEquals(tmp, VELOCITY_TOLERANCE))
                            break;

                        if (Math.Abs(curvel.X) < 1e-4 && Math.Abs(curvel.Y) < 1e-4 && Math.Abs(curvel.Z) < 1e-4)
                        {
                            if (!AbsolutePosition.ApproxEquals(m_lastPosition, POSITION_TOLERANCE))
                                break;
                            if (Math.Abs(m_lastVelocity.X) > 1e-4 ||
                                Math.Abs(m_lastVelocity.Y) > 1e-4 ||
                                Math.Abs(m_lastVelocity.Z) > 1e-4
                                )
                            break;
                        }

                        Vector3 angvel = ClampVectorForTerseUpdate(AngularVelocity, 64f);
                        tmp = ClampVectorForTerseUpdate(m_lastAngularVelocity, 64f);
                        if (!angvel.ApproxEquals(tmp, ANGVELOCITY_TOLERANCE))
                            break;

                        if (Math.Abs(AngularVelocity.X) < 1e-4 && 
                            Math.Abs(AngularVelocity.Y) < 1e-4 &&
                            Math.Abs(AngularVelocity.Z) < 1e-4 &&
                            !RotationOffset.ApproxEquals(m_lastRotation, ROTATION_TOLERANCE)
                            )
                            break;

                        return;
                    }
                }

                if((current & PrimUpdateFlags.TerseUpdate) != 0)
                {
                    m_lastPosition = AbsolutePosition;
                    m_lastRotation = RotationOffset;
                    m_lastVelocity = Velocity;
                    m_lastAcceleration = Acceleration;
                    m_lastAngularVelocity = AngularVelocity;
                    m_lastUpdateSentTime = now;
                }

                UpdateFlag = PrimUpdateFlags.None;
            }

            ParentGroup.Scene.ForEachScenePresence(delegate(ScenePresence avatar)
            {
                SendUpdateToClient(avatar.ControllingClient, current);
            });
        }

        /// <summary>
        /// Send a terse update to all clients
        /// </summary>
        public void SendTerseUpdateToAllClientsInternal()
        {
            if (ParentGroup == null || ParentGroup.Scene == null)
                return;

            lock(UpdateFlagLock)
            {
                UpdateFlag &= ~PrimUpdateFlags.TerseUpdate;

                // Update the "last" values
                m_lastPosition = AbsolutePosition;
                m_lastRotation = RotationOffset;
                m_lastVelocity = Velocity;
                m_lastAcceleration = Acceleration;
                m_lastAngularVelocity = AngularVelocity;
                m_lastUpdateSentTime = Util.GetTimeStampMS();
            }

            ParentGroup.Scene.ForEachClient(delegate(IClientAPI client)
            {
                SendTerseUpdateToClient(client);
            });
        }

        public void SendTerseUpdateToAllClients()
        {
            if (ParentGroup == null || ParentGroup.Scene == null)
                return;

            lock(UpdateFlagLock)
            {
                UpdateFlag &= ~PrimUpdateFlags.TerseUpdate;

                // Update the "last" values
                m_lastPosition = AbsolutePosition;
                m_lastRotation = RotationOffset;
                m_lastVelocity = Velocity;
                m_lastAcceleration = Acceleration;
                m_lastAngularVelocity = AngularVelocity;
                m_lastUpdateSentTime = Util.GetTimeStampMS();
            }

            if (ParentGroup.IsAttachment)
            {
                ScenePresence sp = ParentGroup.Scene.GetScenePresence(ParentGroup.AttachedAvatar);
                sp?.SendAttachmentUpdate(this, PrimUpdateFlags.TerseUpdate);
            }
            else
            {
                ParentGroup.Scene.ForEachClient(delegate(IClientAPI client)
                {
                    SendTerseUpdateToClient(client);
                });
            }
        }

        public void SetAxisRotation(int axis, int rotate)
        {
            ParentGroup.SetAxisRotation(axis, rotate);
        }

        public void SetBuoyancy(float fvalue)
        {
            Buoyancy = fvalue;
        }

        public void SetDieAtEdge(bool p)
        {
            if (ParentGroup.IsDeleted)
                return;

            ParentGroup.RootPart.DIE_AT_EDGE = p;
        }

        public void SetFloatOnWater(int floatYN)
        {
            PhysicsActor pa = PhysActor;

            if (pa != null)
                pa.FloatOnWater = (floatYN == 1);
        }

        public void SetForce(Vector3 force)
        {
            Force = force;
        }

        public PhysicsInertiaData PhysicsInertia
        {
            get
            {
                return m_physicsInertia;
            }
            set
            {
                m_physicsInertia = value;
            }
        }

        public SOPVehicle VehicleParams
        {
            get
            {
                return m_vehicleParams;
            }
            set
            {
                m_vehicleParams = value;

            }
        }

        public int VehicleType
        {
            get
            {
                if (m_vehicleParams == null)
                    return (int)Vehicle.TYPE_NONE;
                else
                    return (int)m_vehicleParams.Type;
            }
            set
            {
                SetVehicleType(value);
            }
        }

        public void SetVehicleType(int type)
        {
                m_vehicleParams = null;

                if (type == (int)Vehicle.TYPE_NONE)
                {
                    if (_parentID ==0 && PhysActor != null)
                        PhysActor.VehicleType = (int)Vehicle.TYPE_NONE;
                    return;
                }
                m_vehicleParams = new SOPVehicle();
                m_vehicleParams.ProcessTypeChange((Vehicle)type);
                {
                    if (_parentID ==0 && PhysActor != null)
                        PhysActor.VehicleType = type;
                    return;
                }
        }

        public void SetVehicleFlags(int param, bool remove)
        {
            if (m_vehicleParams == null)
                return;

            m_vehicleParams.ProcessVehicleFlags(param, remove);

            if (_parentID == 0 && PhysActor != null)
            {
                PhysActor.VehicleFlags(param, remove);
            }
        }

        public void SetVehicleFloatParam(int param, float value)
        {
            if (m_vehicleParams == null)
                return;

            m_vehicleParams.ProcessFloatVehicleParam((Vehicle)param, value);

            if (_parentID == 0 && PhysActor != null)
            {
                PhysActor.VehicleFloatParam(param, value);
            }
        }

        public void SetVehicleVectorParam(int param, Vector3 value)
        {
            if (m_vehicleParams == null)
                return;

            m_vehicleParams.ProcessVectorVehicleParam((Vehicle)param, value);

            if (_parentID == 0 && PhysActor != null)
            {
                PhysActor.VehicleVectorParam(param, value);
            }
        }

        public void SetVehicleRotationParam(int param, Quaternion rotation)
        {
            if (m_vehicleParams == null)
                return;

            m_vehicleParams.ProcessRotationVehicleParam((Vehicle)param, rotation);

            if (_parentID == 0 && PhysActor != null)
            {
                PhysActor.VehicleRotationParam(param, rotation);
            }
        }

        /// <summary>
        /// Set the color & alpha of prim faces
        /// </summary>
        /// <param name="face"></param>
        /// <param name="color"></param>
        /// <param name="alpha"></param>
        public void SetFaceColorAlpha(int face, Vector3 color, float ?alpha)
        {
            Vector3 clippedColor = Vector3.Clamp(color, 0.0f, 1.0f);
            float clippedAlpha = alpha.HasValue ?
                Utils.Clamp(alpha.Value, 0.0f, 1.0f) : 0;

            // The only way to get a deep copy/ If we don't do this, we can
            // never detect color changes further down.
            Byte[] buf = Shape.Textures.GetBytes();
            Primitive.TextureEntry tex = new Primitive.TextureEntry(buf, 0, buf.Length);
            Color4 texcolor;
            int nsides = GetNumberOfSides();
            if (face >= 0 && face < nsides)
            {
                texcolor = tex.CreateFace((uint)face).RGBA;
                texcolor.R = clippedColor.X;
                texcolor.G = clippedColor.Y;
                texcolor.B = clippedColor.Z;
                if (alpha.HasValue)
                {
                    texcolor.A = clippedAlpha;
                }
                tex.FaceTextures[face].RGBA = texcolor;
                UpdateTextureEntry(tex);
                return;
            }
            else if (face == ALL_SIDES)
            {
                for (uint i = 0; i < nsides; i++)
                {
                    if (tex.FaceTextures[i] != null)
                    {
                        texcolor = tex.FaceTextures[i].RGBA;
                        texcolor.R = clippedColor.X;
                        texcolor.G = clippedColor.Y;
                        texcolor.B = clippedColor.Z;
                        if (alpha.HasValue)
                        {
                            texcolor.A = clippedAlpha;
                        }
                        tex.FaceTextures[i].RGBA = texcolor;
                    }
                    texcolor = tex.DefaultTexture.RGBA;
                    texcolor.R = clippedColor.X;
                    texcolor.G = clippedColor.Y;
                    texcolor.B = clippedColor.Z;
                    if (alpha.HasValue)
                    {
                        texcolor.A = clippedAlpha;
                    }
                    tex.DefaultTexture.RGBA = texcolor;
                }
                UpdateTextureEntry(tex);
                return;
            }
        }

        /// <summary>
        /// Get the number of sides that this part has.
        /// </summary>
        /// <returns></returns>
        public int GetNumberOfSides()
        {
            int ret = 0;
            int cut;

            if(Shape.SculptEntry)
            {
                if (Shape.SculptType != (byte)SculptType.Mesh)
                    return 1; // sculp

                //hack to detect new upload with faces data enconded on pbs              
                if ((Shape.ProfileCurve & 0xf0) != (byte)HollowShape.Triangle)
                    // old broken upload TODO
                    return 8;
            }

            PrimType primType = GetPrimType(true);

            switch (primType)
            {
                case PrimType.BOX:
                    ret = 6;
                    if (Shape.ProfileBegin > 0 || Shape.ProfileEnd > 0) // cut case
                    {
                        // removed sides
                        if (Shape.ProfileBegin > 0)
                        {
                            cut = Shape.ProfileBegin;
                            cut /= 12500;
                            ret -= cut;
                        }
                        if (Shape.ProfileEnd > 0)
                        {
                            cut = Shape.ProfileEnd;
                            cut /= 12500;
                            ret -= cut;
                        }
                        ret += 2;
                    }
                    break;
                case PrimType.PRISM:
                    ret = 5;
                    if (Shape.ProfileBegin > 0 || Shape.ProfileEnd > 0) // cut case
                    {
                        // removed sides
                        if (Shape.ProfileBegin > 0)
                        {
                            cut = (Shape.ProfileBegin);
                            if(cut >= 16667 )
                                ret--;
                            if(cut >= 33333 )
                                ret--;
                        }
                        if (Shape.ProfileEnd > 0)
                        {
                            cut = (Shape.ProfileEnd);
                            if(cut >= 16667 )
                                ret--;
                            if(cut >= 33333 )
                                ret--;
                        }
                        ret += 2; // both cut faces
                    }
                    break;
                case PrimType.CYLINDER:
                    ret = 3;
                    if (Shape.ProfileBegin > 0 || Shape.ProfileEnd > 0) // cut
                        ret += 2;
                    break;
                case PrimType.SPHERE:
                    ret = 1;
                    // cut faces exist if cut or skew or unequal twist limits
                    if (Shape.PathBegin > 0 || Shape.PathEnd > 0 || Shape.PathSkew != 0 || (Shape.PathTwistBegin != Shape.PathTwist))
                        ret += 2;
                    if (Shape.ProfileBegin > 0 || Shape.ProfileEnd > 0 || Shape.ProfileHollow > 0) // dimple also if hollow
                        ret += 2;
                    break;
                case PrimType.TORUS:
                    ret = 1;
                    if (Shape.PathBegin > 0 || Shape.PathEnd > 0 || Shape.PathSkew != 0
                            || Shape.PathTaperX != 0 || Shape.PathTaperY != 0 || Shape.PathRevolutions > 0
                            || Shape.PathRadiusOffset != 0 || (Shape.PathTwistBegin != Shape.PathTwist))
                        ret += 2;
                    if (Shape.ProfileBegin > 0 || Shape.ProfileEnd > 0) // profile cut
                        ret += 2;
                    break;
                case PrimType.TUBE:
                    ret = 4;
                    if (Shape.PathBegin > 0 || Shape.PathEnd > 0 || Shape.PathSkew != 0
                            || Shape.PathTaperX != 0 || Shape.PathTaperY != 0 || Shape.PathRevolutions > 0
                            || Shape.PathRadiusOffset != 0 || (Shape.PathTwistBegin != Shape.PathTwist))
                        ret += 2;
                    if (Shape.ProfileBegin > 0 || Shape.ProfileEnd > 0) // profile cut
                    {
                        if (Shape.ProfileBegin > 0)
                        {
                            cut = Shape.ProfileBegin;
                            cut /= 12500;
                            ret -= cut;
                        }
                        if (Shape.ProfileEnd > 0)
                        {
                            cut = Shape.ProfileEnd;
                            cut /= 12500;
                            ret -= cut;
                        }
                        ret += 2;
                    }
                    break;
                case PrimType.RING:
                    ret = 3;
                    if (Shape.PathBegin > 0 || Shape.PathEnd > 0 || Shape.PathSkew != 0
                            || Shape.PathTaperX != 0 || Shape.PathTaperY != 0 || Shape.PathRevolutions > 0
                            || Shape.PathRadiusOffset != 0 || (Shape.PathTwistBegin != Shape.PathTwist))
                        ret += 2;
                    if (Shape.ProfileBegin > 0 || Shape.ProfileEnd > 0) // profile cut
                    {
                        if (Shape.ProfileBegin > 0)
                        {
                            cut = Shape.ProfileBegin;
                            if(cut >= 16667 )
                                ret--;
                            if(cut >= 33333 )
                                ret--;
                        }
                        if (Shape.ProfileEnd > 0)
                        {
                            cut = Shape.ProfileEnd;
                            if(cut >= 16667 )
                                ret--;
                            if(cut >= 33333 )
                                ret--;
                        }
                        ret += 2;
                    }
                    break;
            }

            // hollow face commum to all
            if (Shape.ProfileHollow > 0)
                ret += 1;

            return ret;
        }

        /// <summary>
        /// Tell us what type this prim is
        /// </summary>
        /// <param name="primShape"></param>
        /// <returns></returns>
        public PrimType GetPrimType(bool ignoreSculpt = false)
        {
            if (Shape.SculptEntry && !ignoreSculpt)
                return PrimType.SCULPT;
            ProfileShape ps = (ProfileShape)(Shape.ProfileCurve & 0x07);
            if (ps == ProfileShape.Square)
            {
                if (Shape.PathCurve == (byte)Extrusion.Straight || Shape.PathCurve == (byte)Extrusion.Flexible)
                    return PrimType.BOX;
                else if (Shape.PathCurve == (byte)Extrusion.Curve1)
                    return PrimType.TUBE;
            }
            else if (ps == ProfileShape.Circle)
            {
                if (Shape.PathCurve == (byte)Extrusion.Straight || Shape.PathCurve == (byte)Extrusion.Flexible)
                    return PrimType.CYLINDER;
                // ProfileCurve seems to combine hole shape and profile curve so we need to only compare against the lower 3 bits
                else if (Shape.PathCurve == (byte)Extrusion.Curve1)
                    return PrimType.TORUS;
            }
            else if (ps == ProfileShape.HalfCircle)
            {
                if (Shape.PathCurve == (byte)Extrusion.Curve1 || Shape.PathCurve == (byte)Extrusion.Curve2)
                    return PrimType.SPHERE;
            }
            else if (ps == ProfileShape.EquilateralTriangle)
            {
                if (Shape.PathCurve == (byte)Extrusion.Straight || Shape.PathCurve == (byte)Extrusion.Flexible)
                    return PrimType.PRISM;
                else if (Shape.PathCurve == (byte)Extrusion.Curve1)
                    return PrimType.RING;
            }

            return PrimType.BOX;
        }

        public void SetGroup(UUID groupID, IClientAPI client)
        {
            // Scene.AddNewPrims() calls with client == null so can't use this.
            // m_log.DebugFormat(
            //      "[SCENE OBJECT PART]: Setting group for {0} to {1} for {2}",
            //      Name, groupID, OwnerID);

            ++PseudoCRC;
            GroupID = groupID;
            // if (client != null)
            //      SendPropertiesToClient(client);
            lock(UpdateFlagLock)
                UpdateFlag |= PrimUpdateFlags.FullUpdate;
        }

        /// <summary>
        /// Set the parent group of this prim.
        /// </summary>
        public void SetParent(SceneObjectGroup parent)
        {
            ParentGroup = parent;
        }

        // Use this for attachments!  LocalID should be avatar's localid
        public void SetParentLocalId(uint localID)
        {
            ParentID = localID;
        }

        public void SetPhysicsAxisRotation()
        {
            PhysActor?.LockAngularMotion(RotationAxisLocks);
        }

        /// <summary>
        /// Set the events that this part will pass on to listeners.
        /// </summary>
        /// <param name="scriptid"></param>
        /// <param name="events"></param>
        public void SetScriptEvents(UUID scriptid, ulong events)
        {
            //            m_log.DebugFormat(
            //                "[SCENE OBJECT PART]: Set script events for script with id {0} on {1}/{2} to {3} in {4}",
            //                scriptid, Name, ParentGroup.Name, events, ParentGroup.Scene.Name);
            // scriptEvents oldparts;
            lock (m_scriptEvents)
            {
                if (m_scriptEvents.TryGetValue(scriptid, out scriptEvents ev))
                {
                    if (ev == (scriptEvents)events)
                        return;
                }
                m_scriptEvents[scriptid] = (scriptEvents) events;
            }
            aggregateScriptEvents();
        }

        /// <summary>
        /// Set the text displayed for this part.
        /// </summary>
        /// <param name="text"></param>
        public void SetText(string text)
        {
            osUTF8 old = osUTF8Text;
            if(string.IsNullOrEmpty(text))
            {
                osUTF8Text = null;
                if (old != null && ParentGroup != null)
                {
                    ParentGroup.HasGroupChanged = true;
                    ScheduleFullUpdate();
                }
            }
            else
            {
                osUTF8Text = new osUTF8(text, 254);
                if (ParentGroup != null && !osUTF8Text.Equals(old))
                {
                    ParentGroup.HasGroupChanged = true;
                    ScheduleFullUpdate();
                }
            }
        }

        /// <summary>
        /// Set the text displayed for this part.
        /// </summary>
        /// <param name="text"></param>
        /// <param name="color"></param>
        /// <param name="alpha"></param>
        public void SetText(string text, Vector3 color, double alpha)
        {
            Color oldcolor = Color;

            Color = Color.FromArgb((int) (alpha * 0xff),
                                   (int) (color.X * 0xff),
                                   (int) (color.Y * 0xff),
                                   (int) (color.Z * 0xff));
            osUTF8 old = osUTF8Text;
            if(string.IsNullOrEmpty(text))
            {
                osUTF8Text = null;
                if (ParentGroup != null && (oldcolor != Color || old != null))
                {
                    ParentGroup.HasGroupChanged = true;
                    ScheduleFullUpdate();
                }
            }
            else
            {
                osUTF8Text = new osUTF8(text, 254);
                if (ParentGroup != null && (oldcolor != Color || !osUTF8Text.Equals(old)))
                {
                    ParentGroup.HasGroupChanged = true;
                    ScheduleFullUpdate();
                }
            }
        }

        public void StoreUndoState(ObjectChangeType change)
        {
            lock (m_UndoLock)
            {
                m_UndoRedo ??= new UndoRedoState(5);

                if (!Undoing && !IgnoreUndoUpdate && ParentGroup != null) // just to read better  - undo is in progress, or suspended
                {
                    m_UndoRedo.StoreUndo(this, change);
                }
            }
        }

        /// <summary>
        /// Return number of undos on the stack.  Here temporarily pending a refactor.
        /// </summary>
        public int UndoCount
        {
            get
            {
                if (m_UndoRedo == null)
                    return 0;
                return m_UndoRedo.Count;
            }
        }

        public void Undo()
        {
            lock (m_UndoLock)
            {
                if (m_UndoRedo == null || Undoing || ParentGroup == null)
                    return;

                Undoing = true;
                m_UndoRedo.Undo(this);
                Undoing = false;
            }
        }

        public void Redo()
        {
            lock (m_UndoLock)
            {
                if (m_UndoRedo == null || Undoing || ParentGroup == null)
                    return;

                Undoing = true;
                m_UndoRedo.Redo(this);
                Undoing = false;
            }
        }

        public void ClearUndoState()
        {
            lock (m_UndoLock)
            {
                if (m_UndoRedo == null || Undoing)
                    return;

                m_UndoRedo.Clear();
            }
        }

        public EntityIntersection TestIntersectionOBB(Ray iray, Quaternion parentrot, bool frontFacesOnly, bool faceCenters)
        {
            // In this case we're using a rectangular prism, which has 6 faces and therefore 6 planes
            // This breaks down into the ray---> plane equation.
            // TODO: Change to take shape into account
            Vector3[] vertexes = new Vector3[8];

            // float[] distance = new float[6];
            Vector3[] FaceA = new Vector3[6]; // vertex A for Facei
            Vector3[] FaceB = new Vector3[6]; // vertex B for Facei
            Vector3[] FaceC = new Vector3[6]; // vertex C for Facei
            Vector3[] FaceD = new Vector3[6]; // vertex D for Facei

            Vector3[] normals = new Vector3[6]; // Normal for Facei
            Vector3[] AAfacenormals = new Vector3[6]; // Axis Aligned face normals

            AAfacenormals[0] = new Vector3(1, 0, 0);
            AAfacenormals[1] = new Vector3(0, 1, 0);
            AAfacenormals[2] = new Vector3(-1, 0, 0);
            AAfacenormals[3] = new Vector3(0, -1, 0);
            AAfacenormals[4] = new Vector3(0, 0, 1);
            AAfacenormals[5] = new Vector3(0, 0, -1);

            Vector3 AmBa; // Vertex A - Vertex B
            Vector3 AmBb; // Vertex B - Vertex C
            Vector3 cross;

            Vector3 pos = GetWorldPosition();
            Quaternion rot = GetWorldRotation();

            Quaternion AXrot = rot;
            AXrot.Normalize();

            Vector3 AXpos = pos;

            // tScale is the offset to derive the vertex based on the scale.
            // it's different for each vertex because we've got to rotate it
            // to get the world position of the vertex to produce the Oriented Bounding Box

            Vector3 tScale;
            Vector3 AXscale = m_shape.Scale;
            AXscale *= 0.5f;

            //Vector3 pScale = (AXscale) - (AXrot.Inverse() * (AXscale));
            //Vector3 nScale = (AXscale * -1) - (AXrot.Inverse() * (AXscale * -1));

            // rScale is the rotated offset to find a vertex based on the scale and the world rotation.
            Vector3 rScale;

            // Get Vertexes for Faces Stick them into ABCD for each Face
            // Form: Face<vertex>[face] that corresponds to the below diagram
            #region ABCD Face Vertex Map Comment Diagram
            //                   A _________ B
            //                    |         |
            //                    |  4 top  |
            //                    |_________|
            //                   C           D

            //                   A _________ B
            //                    |  Back   |
            //                    |    3    |
            //                    |_________|
            //                   C           D

            //   A _________ B                     B _________ A
            //    |  Left   |                       |  Right  |
            //    |    0    |                       |    2    |
            //    |_________|                       |_________|
            //   C           D                     D           C

            //                   A _________ B
            //                    |  Front  |
            //                    |    1    |
            //                    |_________|
            //                   C           D

            //                   C _________ D
            //                    |         |
            //                    |  5 bot  |
            //                    |_________|
            //                   A           B
            #endregion

            #region Plane Decomposition of Oriented Bounding Box
            tScale = new Vector3(AXscale.X, -AXscale.Y, AXscale.Z);
            rScale = tScale * AXrot;
            vertexes[0] = (new Vector3((pos.X + rScale.X), (pos.Y + rScale.Y), (pos.Z + rScale.Z)));
               // vertexes[0].X = pos.X + vertexes[0].X;
            //vertexes[0].Y = pos.Y + vertexes[0].Y;
            //vertexes[0].Z = pos.Z + vertexes[0].Z;

            FaceA[0] = vertexes[0];
            FaceB[3] = vertexes[0];
            FaceA[4] = vertexes[0];

            tScale = AXscale;
            rScale = tScale * AXrot;
            vertexes[1] = (new Vector3((pos.X + rScale.X), (pos.Y + rScale.Y), (pos.Z + rScale.Z)));

               // vertexes[1].X = pos.X + vertexes[1].X;
               // vertexes[1].Y = pos.Y + vertexes[1].Y;
            //vertexes[1].Z = pos.Z + vertexes[1].Z;

            FaceB[0] = vertexes[1];
            FaceA[1] = vertexes[1];
            FaceC[4] = vertexes[1];

            tScale = new Vector3(AXscale.X, -AXscale.Y, -AXscale.Z);
            rScale = tScale * AXrot;

            vertexes[2] = (new Vector3((pos.X + rScale.X), (pos.Y + rScale.Y), (pos.Z + rScale.Z)));

            //vertexes[2].X = pos.X + vertexes[2].X;
            //vertexes[2].Y = pos.Y + vertexes[2].Y;
            //vertexes[2].Z = pos.Z + vertexes[2].Z;

            FaceC[0] = vertexes[2];
            FaceD[3] = vertexes[2];
            FaceC[5] = vertexes[2];

            tScale = new Vector3(AXscale.X, AXscale.Y, -AXscale.Z);
            rScale = tScale * AXrot;
            vertexes[3] = (new Vector3((pos.X + rScale.X), (pos.Y + rScale.Y), (pos.Z + rScale.Z)));

            //vertexes[3].X = pos.X + vertexes[3].X;
               // vertexes[3].Y = pos.Y + vertexes[3].Y;
               // vertexes[3].Z = pos.Z + vertexes[3].Z;

            FaceD[0] = vertexes[3];
            FaceC[1] = vertexes[3];
            FaceA[5] = vertexes[3];

            tScale = new Vector3(-AXscale.X, AXscale.Y, AXscale.Z);
            rScale = tScale * AXrot;
            vertexes[4] = (new Vector3((pos.X + rScale.X), (pos.Y + rScale.Y), (pos.Z + rScale.Z)));

               // vertexes[4].X = pos.X + vertexes[4].X;
               // vertexes[4].Y = pos.Y + vertexes[4].Y;
               // vertexes[4].Z = pos.Z + vertexes[4].Z;

            FaceB[1] = vertexes[4];
            FaceA[2] = vertexes[4];
            FaceD[4] = vertexes[4];

            tScale = new Vector3(-AXscale.X, AXscale.Y, -AXscale.Z);
            rScale = tScale * AXrot;
            vertexes[5] = (new Vector3((pos.X + rScale.X), (pos.Y + rScale.Y), (pos.Z + rScale.Z)));

               // vertexes[5].X = pos.X + vertexes[5].X;
               // vertexes[5].Y = pos.Y + vertexes[5].Y;
               // vertexes[5].Z = pos.Z + vertexes[5].Z;

            FaceD[1] = vertexes[5];
            FaceC[2] = vertexes[5];
            FaceB[5] = vertexes[5];

            tScale = new Vector3(-AXscale.X, -AXscale.Y, AXscale.Z);
            rScale = tScale * AXrot;
            vertexes[6] = (new Vector3((pos.X + rScale.X), (pos.Y + rScale.Y), (pos.Z + rScale.Z)));

               // vertexes[6].X = pos.X + vertexes[6].X;
               // vertexes[6].Y = pos.Y + vertexes[6].Y;
               // vertexes[6].Z = pos.Z + vertexes[6].Z;

            FaceB[2] = vertexes[6];
            FaceA[3] = vertexes[6];
            FaceB[4] = vertexes[6];

            tScale = new Vector3(-AXscale.X, -AXscale.Y, -AXscale.Z);
            rScale = tScale * AXrot;
            vertexes[7] = (new Vector3((pos.X + rScale.X), (pos.Y + rScale.Y), (pos.Z + rScale.Z)));

               // vertexes[7].X = pos.X + vertexes[7].X;
               // vertexes[7].Y = pos.Y + vertexes[7].Y;
               // vertexes[7].Z = pos.Z + vertexes[7].Z;

            FaceD[2] = vertexes[7];
            FaceC[3] = vertexes[7];
            FaceD[5] = vertexes[7];
            #endregion

            // Get our plane normals
            for (int i = 0; i < 6; i++)
            {
                //m_log.Info("[FACECALCULATION]: FaceA[" + i + "]=" + FaceA[i] + " FaceB[" + i + "]=" + FaceB[i] + " FaceC[" + i + "]=" + FaceC[i] + " FaceD[" + i + "]=" + FaceD[i]);

                // Our Plane direction
                AmBa = FaceA[i] - FaceB[i];
                AmBb = FaceB[i] - FaceC[i];

                cross = Vector3.Cross(AmBb, AmBa);

                // normalize the cross product to get the normal.
                normals[i] = cross / cross.Length();

                //m_log.Info("[NORMALS]: normals[ " + i + "]" + normals[i].ToString());
                //distance[i] = (normals[i].X * AmBa.X + normals[i].Y * AmBa.Y + normals[i].Z * AmBa.Z) * -1;
            }

            EntityIntersection result = new EntityIntersection()
            {
                distance = 1024
            };

            float c;
            float a;
            float d;
            Vector3 q;

            #region OBB Version 2 Experiment
            //float fmin = 999999;
            //float fmax = -999999;
            //float s = 0;

            //for (int i=0;i<6;i++)
            //{
                //s = iray.Direction.Dot(normals[i]);
                //d = normals[i].Dot(FaceB[i]);

                //if (s == 0)
                //{
                    //if (iray.Origin.Dot(normals[i]) > d)
                    //{
                        //return result;
                    //}
                   // else
                    //{
                        //continue;
                    //}
                //}
                //a = (d - iray.Origin.Dot(normals[i])) / s;
                //if (iray.Direction.Dot(normals[i]) < 0)
                //{
                    //if (a > fmax)
                    //{
                        //if (a > fmin)
                        //{
                            //return result;
                        //}
                        //fmax = a;
                    //}

                //}
                //else
                //{
                    //if (a < fmin)
                    //{
                        //if (a < 0 || a < fmax)
                        //{
                            //return result;
                        //}
                        //fmin = a;
                    //}
                //}
            //}
            //if (fmax > 0)
            //    a= fmax;
            //else
               //     a=fmin;

            //q = iray.Origin + a * iray.Direction;
            #endregion

            // Loop over faces (6 of them)
            for (int i = 0; i < 6; i++)
            {
                //AmBa = FaceA[i] - FaceB[i];
                //AmBb = FaceB[i] - FaceC[i];
                d = Vector3.Dot(normals[i], FaceB[i]);

                //if (faceCenters)
                //{
                //    c = normals[i].Dot(normals[i]);
                //}
                //else
                //{
                c = Vector3.Dot(iray.Direction, normals[i]);
                //}
                if (c == 0)
                    continue;

                a = (d - Vector3.Dot(iray.Origin, normals[i])) / c;

                if (a < 0)
                    continue;

                // If the normal is pointing outside the object
                if (Vector3.Dot(iray.Direction, normals[i]) < 0 || !frontFacesOnly)
                {
                    //if (faceCenters)
                    //{   //(FaceA[i] + FaceB[i] + FaceC[1] + FaceD[i]) / 4f;
                    //    q =  iray.Origin + a * normals[i];
                    //}
                    //else
                    //{
                        q = iray.Origin + iray.Direction * a;
                    //}

                    float distance2 = Vector3.Distance(q, AXpos);
                    // Is this the closest hit to the object's origin?
                    //if (faceCenters)
                    //{
                    //    distance2 = (float)GetDistanceTo(q, iray.Origin);
                    //}

                    if (distance2 < result.distance)
                    {
                        result.distance = distance2;
                        result.HitTF = true;
                        result.ipoint = q;
                        result.face = i;
                        //m_log.Info("[FACE]:" + i.ToString());
                        //m_log.Info("[POINT]: " + q.ToString());
                        //m_log.Info("[DIST]: " + distance2.ToString());
                        if (faceCenters)
                        {
                            result.normal = AAfacenormals[i] * AXrot;

                            Vector3 scaleComponent = AAfacenormals[i];
                            float ScaleOffset = 0.5f;
                            if (scaleComponent.X != 0) ScaleOffset = AXscale.X;
                            if (scaleComponent.Y != 0) ScaleOffset = AXscale.Y;
                            if (scaleComponent.Z != 0) ScaleOffset = AXscale.Z;
                            ScaleOffset = Math.Abs(ScaleOffset);
                            Vector3 offset = result.normal * ScaleOffset;
                            result.ipoint = AXpos + offset;

                            ///pos = (intersectionpoint + offset);
                        }
                        else
                        {
                            result.normal = normals[i];
                        }
                        result.AAfaceNormal = AAfacenormals[i];
                    }
                }
            }
            return result;
        }

        /// <summary>
        /// Serialize this part to xml.
        /// </summary>
        /// <param name="xmlWriter"></param>
        public void ToXml(XmlTextWriter xmlWriter)
        {
            SceneObjectSerializer.SOPToXml2(xmlWriter, this, new Dictionary<string, object>());
        }

        public void TriggerScriptChangedEvent(Changed val, object data = null)
        {
            //if (ParentGroup != null && ParentGroup.Scene != null && (ScriptEvents & scriptEvents.changed) != 0)
            if ((ScriptEvents & scriptEvents.changed) != 0)
                ParentGroup.Scene.EventManager.TriggerOnScriptChangedEvent(LocalId, (uint)val, data);
        }

        public void TrimPermissions()
        {
            BaseMask &= (uint)(PermissionMask.All | PermissionMask.Export);
            OwnerMask &= (uint)(PermissionMask.All | PermissionMask.Export);
            GroupMask &= (uint)PermissionMask.All;
            EveryoneMask &= (uint)(PermissionMask.All | PermissionMask.Export);
            NextOwnerMask &= (uint)PermissionMask.All;
        }

        public void UpdateExtraParam(ushort type, bool inUse, byte[] data)
        {
            m_shape.ReadInUpdateExtraParam(type, inUse, data);

            if (ParentGroup != null)
            {
                ParentGroup.HasGroupChanged = true;
                ScheduleFullAnimUpdate();
            }
        }

        public void UpdateGroupPosition(Vector3 newPos)
        {
            Vector3 oldPos = GroupPosition;
            if (oldPos.NotEqual(newPos))
            {
                GroupPosition = newPos;
                ScheduleTerseUpdate();
            }
        }

        /// <summary>
        /// Update this part's offset position.
        /// </summary>
        /// <param name="pos"></param>
        public void UpdateOffSet(Vector3 newPos)
        {
            Vector3 oldPos = OffsetPosition;
            if (oldPos.NotEqual(newPos))
            {
                if (ParentGroup.RootPart.GetStatusSandbox())
                {
                    if (Vector3.DistanceSquared(ParentGroup.RootPart.StatusSandboxPos, newPos) > 100)
                    {
                        ParentGroup.RootPart.ScriptSetPhysicsStatus(false);
                        newPos = OffsetPosition;
                        ParentGroup.Scene.SimChat(Utils.StringToBytes("Hit Sandbox Limit"),
                              ChatTypeEnum.DebugChannel, 0x7FFFFFFF, ParentGroup.RootPart.AbsolutePosition, Name, UUID, false);
                    }
                }

                OffsetPosition = newPos;
                ScheduleTerseUpdate();
            }
        }

        /// <summary>
        /// Update permissions on the SOP. Should only be called from SOG.UpdatePermissions because the SOG
        /// will handle the client notifications once all of its parts are updated.
        /// </summary>
        /// <param name="AgentID"></param>
        /// <param name="field"></param>
        /// <param name="localID"></param>
        /// <param name="mask"></param>
        /// <param name="addRemTF"></param>
        public void UpdatePermissions(UUID AgentID, byte field, uint localID, uint mask, byte addRemTF)
        {
            bool god = ParentGroup.Scene.Permissions.IsGod(AgentID);

            bool canChange = god || AgentID.Equals(OwnerID) ||
                        ParentGroup.Scene.Permissions.CanEditObjectPermissions(ParentGroup, AgentID);

            if (canChange)
            {
                bool set = addRemTF == 1;
                uint baseMask = god ? 0x7ffffff0 : BaseMask;
                switch (field)
                {
                    case 1:
                        if (god)
                        {
                            BaseMask = ApplyMask(BaseMask, set, mask);
                            Inventory.ApplyGodPermissions(BaseMask);
                        }

                        break;
                    case 2:
                        OwnerMask = ApplyMask(OwnerMask, set, mask) & baseMask;
                        break;
                    case 4:
                        GroupMask = ApplyMask(GroupMask, set, mask) & baseMask;
                        break;
                    case 8:
                        // Trying to set export permissions - extra checks
                        if (set && (mask & (uint)PermissionMask.Export) != 0)
                        {
                            if ((OwnerMask & (uint)PermissionMask.Export) == 0 || (BaseMask & (uint)PermissionMask.Export) == 0 || (NextOwnerMask & (uint)PermissionMask.All) != (uint)PermissionMask.All)
                                mask &= ~(uint)PermissionMask.Export;
                        }
                        EveryoneMask = ApplyMask(EveryoneMask, set, mask) &
                                baseMask;
                        break;
                    case 16:
                        // Force full perm if export
                        if ((EveryoneMask & (uint)PermissionMask.Export) != 0)
                        {
                            NextOwnerMask = (uint)PermissionMask.All;
                            break;
                        }
                        NextOwnerMask = ApplyMask(NextOwnerMask, set, mask) &
                                baseMask;
                        // Prevent the client from creating no copy, no transfer
                        // objects
                        if ((NextOwnerMask & (uint)PermissionMask.Copy) == 0)
                            NextOwnerMask |= (uint)PermissionMask.Transfer;

                        NextOwnerMask |= (uint)PermissionMask.Move;

                        break;
                }
                AggregateInnerPerms();
                SendFullUpdateToAllClients();
            }
        }

        public void ClonePermissions(SceneObjectPart source)
        {
            uint prevOwnerMask = OwnerMask;
            uint prevGroupMask = GroupMask;
            uint prevEveryoneMask = EveryoneMask;
            uint prevNextOwnerMask = NextOwnerMask;

            OwnerMask = source.OwnerMask & BaseMask;
            GroupMask = source.GroupMask & BaseMask;
            EveryoneMask = source.EveryoneMask & BaseMask;
            NextOwnerMask = source.NextOwnerMask & BaseMask;

            AggregateInnerPerms();

            if (OwnerMask != prevOwnerMask || GroupMask != prevGroupMask ||
                    EveryoneMask != prevEveryoneMask || NextOwnerMask != prevNextOwnerMask)
                SendFullUpdateToAllClients();
        }

        public void UpdateExtraPhysics(ExtraPhysicsData physdata)
        {
            if (physdata.PhysShapeType == PhysShapeType.invalid || ParentGroup == null)
                return;

            byte newtype = (byte)physdata.PhysShapeType;
            if (PhysicsShapeType != newtype)
                PhysicsShapeType = newtype;

            if(Density != physdata.Density)
                Density = physdata.Density;

            if(GravityModifier != physdata.GravitationModifier)
                GravityModifier = physdata.GravitationModifier;

            if(Friction != physdata.Friction)
                Friction = physdata.Friction;

            if(Restitution != physdata.Bounce)
                Restitution = physdata.Bounce;
        }
        /// <summary>
        /// Update the flags on this prim.  This covers properties such as phantom, physics and temporary.
        /// </summary>
        /// <param name="UsePhysics"></param>
        /// <param name="SetTemporary"></param>
        /// <param name="SetPhantom"></param>
        /// <param name="SetVD"></param>
        public void UpdatePrimFlags(bool UsePhysics, bool SetTemporary, bool SetPhantom, bool SetVD, bool building)
        {
            bool wasUsingPhysics = ((m_flags & PrimFlags.Physics) != 0);
            bool wasTemporary = ((m_flags & PrimFlags.TemporaryOnRez) != 0);
            bool wasPhantom = ((m_flags & PrimFlags.Phantom) != 0);
            bool wasVD = VolumeDetectActive;

            if ((UsePhysics == wasUsingPhysics) && (wasTemporary == SetTemporary) && (wasPhantom == SetPhantom) && (SetVD == wasVD))
            {
                UpdatePhysicsSubscribedEvents();
                return;
            }

            VolumeDetectActive = SetVD;

            // volume detector implies phantom we need to decouple this mess
            if (SetVD)
                SetPhantom = true;
            else if(wasVD)
                SetPhantom = false;

            if (UsePhysics)
                AddFlag(PrimFlags.Physics);
            else
                RemFlag(PrimFlags.Physics);

            if (SetPhantom)
                AddFlag(PrimFlags.Phantom);
            else
                RemFlag(PrimFlags.Phantom);

            if (SetTemporary)
                AddFlag(PrimFlags.TemporaryOnRez);
            else
                RemFlag(PrimFlags.TemporaryOnRez);

            if (ParentGroup.Scene == null)
                return;

            PhysicsActor pa = PhysActor;

            if (pa != null && building && pa.Building != building)
                pa.Building = building;

            if ((SetPhantom && !UsePhysics && !SetVD) ||  ParentGroup.IsAttachment || PhysicsShapeType == (byte)PhysShapeType.none
                || (Shape.PathCurve == (byte)Extrusion.Flexible))
            {
                Stop();
                if (pa != null)
                {
                    if(wasUsingPhysics)
                        ParentGroup.Scene.RemovePhysicalPrim(1);
                    RemoveFromPhysics();
                }
            }

            else
            {
                if (ParentGroup.Scene.CollidablePrims)
                {
                    if (pa == null)
                    {
                        AddToPhysics(UsePhysics, SetPhantom, building, false);
                        pa = PhysActor;

                        if (pa != null)
                        {
                            pa.SetMaterial(Material);
                            DoPhysicsPropertyUpdate(UsePhysics, true);
                        }
                    }
                    else // it already has a physical representation
                    {

                        DoPhysicsPropertyUpdate(UsePhysics, false); // Update physical status.

                        if(UsePhysics && !SetPhantom &&  m_localId == ParentGroup.RootPart.LocalId &&
                                m_vehicleParams != null && m_vehicleParams.CameraDecoupled)
                            AddFlag(PrimFlags.CameraDecoupled);
                        else
                            RemFlag(PrimFlags.CameraDecoupled);

                        if (pa.Building != building)
                            pa.Building = building;
                    }

                    UpdatePhysicsSubscribedEvents();
                }
            }

            // and last in case we have a new actor and not building

            if (ParentGroup != null)
            {
                ParentGroup.HasGroupChanged = true;
                ScheduleFullUpdate();
            }

//            m_log.DebugFormat("[SCENE OBJECT PART]: Updated PrimFlags on {0} {1} to {2}", Name, LocalId, Flags);
        }

        /// <summary>
        /// Adds this part to the physics scene.
        /// and sets the PhysActor property
        /// </summary>
        /// <param name="isPhysical">Add this prim as physical.</param>
        /// <param name="isPhantom">Add this prim as phantom.</param>
        /// <param name="building">tells physics to delay full construction of object</param>
        /// <param name="applyDynamics">applies velocities, force and torque</param>
        private void AddToPhysics(bool isPhysical, bool isPhantom, bool building, bool applyDynamics)
        {
            if (ParentGroup.Scene != null)
                ClampScale(isPhysical);

            PhysicsActor pa;
            Vector3 velocity = Velocity;
            Vector3 rotationalVelocity = AngularVelocity;

            try
            {
                pa = ParentGroup.Scene.PhysicsScene.AddPrimShape(
                                 string.Format("{0}/{1}", Name, UUID),
                                 Shape,
                                 AbsolutePosition,
                                 Scale,
                                 GetWorldRotation(),
                                 isPhysical,
                                 isPhantom,
                                 PhysicsShapeType,
                                 m_localId);
            }
            catch (Exception e)
            {
                m_log.ErrorFormat("[SCENE]: caught exception meshing object {0}. Object set to phantom. e={1}", m_uuid, e);
                pa = null;
            }

            if (pa != null)
            {
                pa.SOPName = Name;
                pa.SetMaterial(Material);

                pa.Density = Density;
                pa.GravModifier = GravityModifier;
                pa.Friction = Friction;
                pa.Restitution = Restitution;
                pa.Buoyancy = Buoyancy;

                if(LocalId == ParentGroup.RootPart.LocalId)
                {
                    pa.LockAngularMotion(RotationAxisLocks);
                }

                if (VolumeDetectActive) // change if not the default only
                    pa.SetVolumeDetect(1);
 
                bool isroot = (m_localId == ParentGroup.RootPart.LocalId);

                if(isroot && m_physicsInertia != null)
                    pa.SetInertiaData(m_physicsInertia);

                if (isroot && m_vehicleParams != null )
                {
                    m_vehicleParams.SetVehicle(pa);
                    if(isPhysical && !isPhantom && m_vehicleParams.CameraDecoupled)
                        AddFlag(PrimFlags.CameraDecoupled);
                    else
                        RemFlag(PrimFlags.CameraDecoupled);
                }
                else
                    RemFlag(PrimFlags.CameraDecoupled);
                // we are going to tell rest of code about physics so better have this here
                PhysActor = pa;

                //                DoPhysicsPropertyUpdate(isPhysical, true);
                // lets expand it here just with what it really needs to do

                if (isPhysical)
                {
                    ParentGroup.RootPart.KeyframeMotion?.Stop();
                    ParentGroup.RootPart.KeyframeMotion = null;
                    ParentGroup.Scene.AddPhysicalPrim(1);

                    pa.OnRequestTerseUpdate += PhysicsRequestingTerseUpdate;
                    pa.OnOutOfBounds += PhysicsOutOfBounds;

                    if (_parentID != 0 && _parentID != LocalId)
                    {
                        PhysicsActor parentPa = ParentGroup.RootPart.PhysActor;

                        if (parentPa != null)
                        {
                            pa.link(parentPa);
                        }
                    }
                }

                if (applyDynamics && LocalId == ParentGroup.RootPart.LocalId)
                    // do independent of isphysical so parameters get setted (at least some)
                {
                    Velocity = velocity;
                    AngularVelocity = rotationalVelocity;

                    // if not vehicle and root part apply force and torque
                    if ((m_vehicleParams == null || m_vehicleParams.Type == Vehicle.TYPE_NONE))
                    {
                        pa.Force = Force;
                        pa.Torque = Torque;
                    }
                }

                if (!building)
                    pa.Building = false;
            }

            PhysActor = pa;

            ParentGroup.Scene.EventManager.TriggerObjectAddedToPhysicalScene(this);
        }

        /// <summary>
        /// This removes the part from the physics scene.
        /// </summary>
        /// <remarks>
        /// This isn't the same as turning off physical, since even without being physical the prim has a physics
        /// representation for collision detection.
        /// </remarks>
        public void RemoveFromPhysics()
        {
            PhysicsActor pa = PhysActor;
            if (pa != null)
            {
                pa.OnCollisionUpdate -= PhysicsCollision;
                pa.OnRequestTerseUpdate -= PhysicsRequestingTerseUpdate;
                pa.OnOutOfBounds -= PhysicsOutOfBounds;

                ParentGroup.Scene.PhysicsScene.RemovePrim(pa);

                ParentGroup.Scene.EventManager.TriggerObjectRemovedFromPhysicalScene(this);
            }
            RemFlag(PrimFlags.CameraDecoupled);
            PhysActor = null;
        }

        /// <summary>
        /// This updates the part's rotation and sends out an update to clients if necessary.
        /// </summary>
        /// <param name="rot"></param>
        public void UpdateRotation(Quaternion rot)
        {
            if (rot.NotEqual(RotationOffset))
            {
                RotationOffset = rot;
                if (ParentGroup is not null)
                {
                    ParentGroup.HasGroupChanged = true;
                    ScheduleTerseUpdate();
                }
            }
        }

        /// <summary>
        /// Update the shape of this part.
        /// </summary>
        /// <param name="shapeBlock"></param>
        public void UpdateShape(ObjectShapePacket.ObjectDataBlock shapeBlock)
        {
            m_shape.PathBegin = shapeBlock.PathBegin;
            m_shape.PathEnd = shapeBlock.PathEnd;
            m_shape.PathScaleX = shapeBlock.PathScaleX;
            m_shape.PathScaleY = shapeBlock.PathScaleY;
            m_shape.PathShearX = shapeBlock.PathShearX;
            m_shape.PathShearY = shapeBlock.PathShearY;
            m_shape.PathSkew = shapeBlock.PathSkew;
            m_shape.ProfileBegin = shapeBlock.ProfileBegin;
            m_shape.ProfileEnd = shapeBlock.ProfileEnd;
            m_shape.PathCurve = shapeBlock.PathCurve;
            m_shape.ProfileCurve = shapeBlock.ProfileCurve;
            m_shape.ProfileHollow = shapeBlock.ProfileHollow;
            m_shape.PathRadiusOffset = shapeBlock.PathRadiusOffset;
            m_shape.PathRevolutions = shapeBlock.PathRevolutions;
            m_shape.PathTaperX = shapeBlock.PathTaperX;
            m_shape.PathTaperY = shapeBlock.PathTaperY;
            m_shape.PathTwist = shapeBlock.PathTwist;
            m_shape.PathTwistBegin = shapeBlock.PathTwistBegin;

            PhysicsActor pa = PhysActor;
            if (pa is not null)
                pa.Shape = m_shape;

            // This is what makes vehicle trailers work
            // A script in a child prim re-issues
            // llSetPrimitiveParams(PRIM_TYPE) every few seconds. That
            // prevents autoreturn. This is not well known. It also works
            // in SL.
            //
            if (ParentGroup.RootPart != this)
                ParentGroup.RootPart.Rezzed = DateTime.UtcNow;

            ParentGroup.HasGroupChanged = true;
            TriggerScriptChangedEvent(Changed.SHAPE);
            ScheduleFullUpdate();
        }

        public void UpdateSlice(float begin, float end)
        {
            if (end < begin)
                (end, begin) = (begin, end);

            end = Math.Min(1f, Math.Max(0f, end));
            begin = Math.Min(Math.Min(1f, Math.Max(0f, begin)), end - 0.02f);
            if (begin < 0.02f && end < 0.02f)
            {
                begin = 0f;
                end = 0.02f;
            }

            ushort uBegin = (ushort)(50000.0f * begin);
            ushort uEnd = (ushort)(50000.0f * (1f - end));
            bool updatePossiblyNeeded = false;
            PrimType primType = GetPrimType();
            if (primType == PrimType.SPHERE || primType == PrimType.TORUS || primType == PrimType.TUBE || primType == PrimType.RING)
            {
                if (m_shape.ProfileBegin != uBegin || m_shape.ProfileEnd != uEnd)
                {
                    m_shape.ProfileBegin = uBegin;
                    m_shape.ProfileEnd = uEnd;
                    updatePossiblyNeeded = true;
                }
            }
            else if (m_shape.PathBegin != uBegin || m_shape.PathEnd != uEnd)
            {
                m_shape.PathBegin = uBegin;
                m_shape.PathEnd = uEnd;
                updatePossiblyNeeded = true;
            }

            if (updatePossiblyNeeded && ParentGroup != null)
            {
                ParentGroup.HasGroupChanged = true;
            }
            if (updatePossiblyNeeded && PhysActor != null)
            {
                PhysActor.Shape = m_shape;
            }
            if (updatePossiblyNeeded)
            {
                ScheduleFullUpdate();
            }
        }

        /// <summary>
        /// Update the texture entry for this part.
        /// </summary>
        /// <param name="serializedTextureEntry"></param>
        public void UpdateTextureEntry(byte[] serializedTextureEntry)
        {
            Primitive.TextureEntry newTex = new Primitive.TextureEntry(serializedTextureEntry, 0, serializedTextureEntry.Length);
            Primitive.TextureEntry oldTex = Shape.Textures;

            Changed changeFlags = 0;

            Primitive.TextureEntryFace defaultNewFace = newTex.DefaultTexture;
            Primitive.TextureEntryFace defaultOldFace = oldTex.DefaultTexture;

            // On Incoming packets, sometimes newText.DefaultTexture is null.  The assumption is that all
            // other prim-sides are set, but apparently that's not always the case.  Lets assume packet/data corruption at this point.
            if (defaultNewFace == null)
            {
                defaultNewFace = new Primitive.TextureEntry(Util.BLANK_TEXTURE_UUID).CreateFace(0);
                newTex.DefaultTexture = defaultNewFace;
            }
            if (defaultOldFace == null)
            {
                defaultOldFace = new Primitive.TextureEntry(Util.BLANK_TEXTURE_UUID).CreateFace(0);
                oldTex.DefaultTexture = defaultOldFace;
            }

            // Materials capable viewers can send a ObjectImage packet
            // when nothing in TE has changed. MaterialID should be updated
            // by the RenderMaterials CAP handler, so updating it here may cause a
            // race condtion. Therefore, if no non-materials TE fields have not changed,
            // we should ignore any changes and not update Shape.TextureEntry

            bool otherFieldsChanged = false;
            int nsides = GetNumberOfSides();
            for (int i = 0; i < nsides; i++)
            {
                Primitive.TextureEntryFace newFace = defaultNewFace;
                Primitive.TextureEntryFace oldFace = defaultOldFace;
                if (oldTex.FaceTextures[i] != null)
                    oldFace = oldTex.FaceTextures[i];
                if (newTex.FaceTextures[i] != null)
                    newFace = newTex.FaceTextures[i];

                if (oldFace.TextureID != newFace.TextureID)
                    changeFlags |= Changed.TEXTURE;

                Color4 oldRGBA = oldFace.RGBA;
                Color4 newRGBA = newFace.RGBA;

                if (oldRGBA.R != newRGBA.R ||
                    oldRGBA.G != newRGBA.G ||
                    oldRGBA.B != newRGBA.B ||
                    oldRGBA.A != newRGBA.A)
                    changeFlags |= Changed.COLOR;

                // Max change, skip the rest of testing
                if (changeFlags == (Changed.TEXTURE | Changed.COLOR))
                    break;

                if (!otherFieldsChanged)
                {
                    if (oldFace.Bump != newFace.Bump) otherFieldsChanged = true;
                    if (oldFace.Fullbright != newFace.Fullbright) otherFieldsChanged = true;
                    if (oldFace.Glow != newFace.Glow) otherFieldsChanged = true;
                    if (oldFace.MediaFlags != newFace.MediaFlags) otherFieldsChanged = true;
                    if (oldFace.OffsetU != newFace.OffsetU) otherFieldsChanged = true;
                    if (oldFace.OffsetV != newFace.OffsetV) otherFieldsChanged = true;
                    if (oldFace.RepeatU != newFace.RepeatU) otherFieldsChanged = true;
                    if (oldFace.RepeatV != newFace.RepeatV) otherFieldsChanged = true;
                    if (oldFace.Rotation != newFace.Rotation) otherFieldsChanged = true;
                    if (oldFace.Shiny != newFace.Shiny) otherFieldsChanged = true;
                    if (oldFace.TexMapType != newFace.TexMapType) otherFieldsChanged = true;
                    if (otherFieldsChanged)
                        changeFlags |= Changed.TEXTURE;
                }
            }

            if (changeFlags == 0)
                return;
            // we do need better compacter do just the trivial case
            if(nsides == 1 && newTex.FaceTextures[0] != null)
            {
                newTex.DefaultTexture = newTex.GetFace(0);
                newTex.FaceTextures[0] = null;
            }
            m_shape.TextureEntry = newTex.GetBytes(nsides);
            TriggerScriptChangedEvent(changeFlags);
            ParentGroup.HasGroupChanged = true;
            ScheduleUpdate(PrimUpdateFlags.Textures);
        }

        /// <summary>
        /// Update the texture entry for this part.
        /// </summary>
        /// <param name="newTex"></param>
        public void UpdateTextureEntry(Primitive.TextureEntry newTex)
        {
            TextureAttributes dirty = newTex.GetDirtyFlags(32, true);
            dirty &= ~TextureAttributes.MaterialID;
            if(dirty == TextureAttributes.None)
                return;

            Changed changeFlags = 0;
            if((dirty & TextureAttributes.RGBA) != 0)
            {
                changeFlags = Changed.COLOR;
                dirty &= ~TextureAttributes.RGBA;
            }
            if (dirty != TextureAttributes.None)
                changeFlags |= Changed.TEXTURE;

            if (changeFlags == 0)
                return;

            m_shape.TextureEntry = newTex.GetBytes(9);
            TriggerScriptChangedEvent(changeFlags);
            ParentGroup.HasGroupChanged = true;
            ScheduleUpdate(PrimUpdateFlags.Textures);
        }

        internal void UpdatePhysicsSubscribedEvents()
        {
            PhysicsActor pa = PhysActor;
            if (pa == null)
                return;

            pa.OnCollisionUpdate -= PhysicsCollision;

            bool hassound = (!VolumeDetectActive && CollisionSoundType >= 0 && ((m_flags & PrimFlags.Physics) != 0));

            scriptEvents CombinedEvents = AggregatedScriptEvents;

            // merge with root part
            if (ParentGroup != null && ParentGroup.RootPart != null)
                CombinedEvents |= ParentGroup.RootPart.AggregatedScriptEvents;

            // submit to this part case
            if (VolumeDetectActive)
                CombinedEvents &= PhyscicsVolumeDtcSubsEvents;
            else if ((m_flags & PrimFlags.Phantom) != 0)
                CombinedEvents &= PhyscicsPhantonSubsEvents;
            else
                CombinedEvents &= PhysicsNeededSubsEvents;

            if (hassound || CombinedEvents != 0)
            {
                // subscribe to physics updates.
                pa.OnCollisionUpdate += PhysicsCollision;
                pa.SubscribeEvents(50); // 20 reports per second
            }
            else
            {
                pa.UnSubscribeEvents();
            }
        }

        public void aggregateScriptEvents()
        {
            if (ParentGroup == null || ParentGroup.RootPart == null)
                return;

            AggregatedScriptEvents = 0;

            // Aggregate script events
            lock (m_scriptEvents)
            {
                foreach (scriptEvents s in m_scriptEvents.Values)
                {
                    AggregatedScriptEvents |= s;
                }
            }

            uint objectflagupdate = 0;
            if ((AggregatedScriptEvents & scriptEvents.anytouch) != 0 )
            {
                objectflagupdate |= (uint) PrimFlags.Touch;
            }

            if ((AggregatedScriptEvents & scriptEvents.money) != 0)
            {
                objectflagupdate |= (uint) PrimFlags.Money;
            }

            if (AllowedDrop)
            {
                objectflagupdate |= (uint) PrimFlags.AllowInventoryDrop;
            }

            m_localFlags = (PrimFlags)objectflagupdate;

            if ((AggregatedScriptEvents & scriptEvents.email) != 0)
            {
                IEmailModule imm = ParentGroup.Scene.RequestModuleInterface<IEmailModule>();
                imm?.AddPartMailBox(UUID);
            }

            if (ParentGroup.RootPart == this)
            {
                ParentGroup.aggregateScriptEvents();
            }
            else
            {
//                m_log.DebugFormat(
//                    "[SCENE OBJECT PART]: Scheduling part {0} {1} for full update in aggregateScriptEvents()", Name, LocalId);
                UpdatePhysicsSubscribedEvents();
                ScheduleFullUpdate();
            }
        }

        public void SetCameraAtOffset(Vector3 v)
        {
            m_cameraAtOffset = v;
        }

        public void SetCameraEyeOffset(Vector3 v)
        {
            m_cameraEyeOffset = v;
        }

        public void SetForceMouselook(bool force)
        {
            m_forceMouselook = force;
        }

        public Vector3 GetCameraAtOffset()
        {
            return m_cameraAtOffset;
        }

        public Vector3 GetCameraEyeOffset()
        {
            return m_cameraEyeOffset;
        }

        public bool GetForceMouselook()
        {
            return m_forceMouselook;
        }

        public override string ToString()
        {
            return String.Format("{0} {1} (parent {2}))", Name, UUID, ParentGroup);
        }

        #endregion Public Methods

        public void SendUpdateToClient(IClientAPI remoteClient, PrimUpdateFlags update)
        {
            if (ParentGroup.IsDeleted || !remoteClient.IsActive)
                return;

            if (Animations == null)
            {
                update &= ~PrimUpdateFlags.Animations;
                if (update == PrimUpdateFlags.None)
                    return;
            }

            if (ParentGroup.IsAttachment && 
                    (ParentGroup.RootPart != this || ParentGroup.AttachedAvatar != remoteClient.AgentId && ParentGroup.HasPrivateAttachmentPoint))
                return;
 
            remoteClient.SendEntityUpdate(this, update);

            ParentGroup.Scene.StatsReporter.AddObjectUpdates(1);
        }


        public void SendTerseUpdateToClient(IClientAPI remoteClient)
        {
            if (ParentGroup.IsDeleted)
                return;

            if (ParentGroup.IsAttachment
                && (ParentGroup.RootPart != this
                    || ParentGroup.AttachedAvatar != remoteClient.AgentId && ParentGroup.HasPrivateAttachmentPoint))
                return;

            // Causes this thread to dig into the Client Thread Data.
            // Remember your locking here!
            remoteClient.SendEntityUpdate(this, PrimUpdateFlags.TerseUpdate);

            ParentGroup.Scene.StatsReporter.AddObjectUpdates(1);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static void AddScriptLPS(int count)
        {
            //legacy, do nothing
            //ParentGroup.AddScriptLPS(count);
        }

        /// <summary>
        /// Sets a prim's owner and permissions when it's rezzed.
        /// </summary>
        /// <param name="item">The inventory item from which the item was rezzed</param>
        /// <param name="userInventory">True: the item is being rezzed from the user's inventory. False: from a prim's inventory.</param>
        /// <param name="scene">The scene the prim is being rezzed into</param>
        public void ApplyPermissionsOnRez(InventoryItemBase item, bool userInventory, Scene scene)
        {
            if ((OwnerID != item.Owner) || ((item.CurrentPermissions & (uint)PermissionMask.Slam) != 0) || ((item.Flags & (uint)InventoryItemFlags.ObjectSlamPerm) != 0))
            {
                if (scene.Permissions.PropagatePermissions())
                {
                    if ((item.Flags & (uint)InventoryItemFlags.ObjectHasMultipleItems) == 0)
                    {
                        // Apply the item's permissions to the object
                        //LogPermissions("Before applying item permissions");
                        if (userInventory)
                        {
                            EveryoneMask = item.EveryOnePermissions;
                            NextOwnerMask = item.NextPermissions;
                        }
                        else
                        {
                            if ((item.Flags & (uint)InventoryItemFlags.ObjectOverwriteEveryone) != 0)
                                EveryoneMask = item.EveryOnePermissions;
                            if ((item.Flags & (uint)InventoryItemFlags.ObjectOverwriteNextOwner) != 0)
                                NextOwnerMask = item.NextPermissions;
                            if ((item.Flags & (uint)InventoryItemFlags.ObjectOverwriteGroup) != 0)
                                GroupMask = item.GroupPermissions;
                        }
                        //LogPermissions("After applying item permissions");
                    }
                }

                GroupMask = 0; // DO NOT propagate here
            }

            if (OwnerID.NotEqual(item.Owner))
            {
                if(OwnerID.NotEqual(GroupID))
                    LastOwnerID = OwnerID;
                OwnerID = item.Owner;
                Inventory.ChangeInventoryOwner(item.Owner);

                if (scene.Permissions.PropagatePermissions())
                    ApplyNextOwnerPermissions();
            }
        }

        /// <summary>
        /// Logs the prim's permissions. Useful when debugging permission problems.
        /// </summary>
        /// <param name="message"></param>
        private void LogPermissions(String message)
        {
            PermissionsUtil.LogPermissions(Name, message, BaseMask, OwnerMask, NextOwnerMask);
        }

        public void ApplyNextOwnerPermissions()
        {
            // Export needs to be preserved in the base and everyone
            // mask, but removed in the owner mask as a next owner
            // can never change the export status
            BaseMask &= (NextOwnerMask | (uint)PermissionMask.Export);
            OwnerMask &= NextOwnerMask;
            EveryoneMask &= (NextOwnerMask | (uint)PermissionMask.Export);
            GroupMask = 0; // Giving an object zaps group permissions

            Inventory.ApplyNextOwnerPermissions();
            AggregateInnerPerms();
        }

        public void UpdateLookAt()
        {
            try
            {
                if (APIDActive)
                {
                    PhysicsActor pa = ParentGroup.RootPart.PhysActor;
                    if (pa == null || !pa.IsPhysical || APIDStrength < 0.04)
                    {
                        StopLookAt();
                        return;
                    }

                    Quaternion currRot = GetWorldRotation();
                    currRot.Normalize();

                    // difference between current orientation and desired orientation
                    Quaternion dR = currRot / APIDTarget;

                    // find axis and angle of rotation to rotate to desired orientation
                    dR.GetAxisAngle(out Vector3 axis, out float angle);
                    axis *= currRot;

                    // clamp strength to avoid overshoot
                    float strength = 1.0f / APIDStrength;
                    if (strength > 1.0) strength = 1.0f;

                    // set angular velocity to rotate to desired orientation
                    // with velocity proportional to strength and angle
                    AngularVelocity = axis * angle * strength * (float)Math.PI;

                    // This ensures that we'll check this object on the next iteration
                    ParentGroup.QueueForUpdateCheck();
                }
            }
            catch (Exception ex)
            {
                m_log.Error("[Physics] " + ex);
            }
        }

        public Color4 GetTextColor()
        {
            Color color = Color;
            return new Color4(color.R, color.G, color.B, (byte)(0xFF - color.A));
        }

        public void ResetOwnerChangeFlag()
        {
            List<UUID> inv = Inventory.GetInventoryList();

            foreach (UUID itemID in inv)
            {
                TaskInventoryItem item = Inventory.GetInventoryItem(itemID);
                item.OwnerChanged = false;
                Inventory.UpdateInventoryItem(item, false, false);
            }
            AggregateInnerPerms();
        }

        /// <summary>
        /// Record an avatar sitting on this part.
        /// </summary>
        /// <remarks>This is called for all the sitting avatars whether there is a sit target set or not.</remarks>
        /// <returns>
        /// true if the avatar was not already recorded, false otherwise.
        /// </returns>
        /// <param name='avatarId'></param>
        protected internal bool AddSittingAvatar(ScenePresence sp)
        {
            lock (ParentGroup.m_sittingAvatars)
            {
                if (IsSitTargetSet && SitTargetAvatar.IsZero())
                    SitTargetAvatar = sp.UUID;

                m_sittingAvatars ??= new HashSet<ScenePresence>();

                if (m_sittingAvatars.Add(sp))
                {
                    if(!ParentGroup.m_sittingAvatars.Contains(sp))
                        ParentGroup.m_sittingAvatars.Add(sp);

                    return true;
                }

                return false;
            }
        }

        /// <summary>
        /// Remove an avatar recorded as sitting on this part.
        /// </summary>
        /// <remarks>This applies to all sitting avatars whether there is a sit target set or not.</remarks>
        /// <returns>
        /// true if the avatar was present and removed, false if it was not present.
        /// </returns>
        /// <param name='avatarId'></param>
        protected internal bool RemoveSittingAvatar(ScenePresence sp)
        {
            lock (ParentGroup.m_sittingAvatars)
            {
                if (SitTargetAvatar.Equals(sp.UUID))
                    SitTargetAvatar = UUID.Zero;

                if (m_sittingAvatars == null)
                    return false;

                if (m_sittingAvatars.Remove(sp))
                {
                    if (m_sittingAvatars.Count == 0)
                        m_sittingAvatars = null;

                    if(ParentGroup.m_sittingAvatars.Remove(sp))
                        ParentGroup.InvalidatePartsLinkMaps(false);
                    return true;
                }

                return false;
            }
        }

        /// <summary>
        /// Get a copy of the list of sitting avatars.
        /// </summary>
        /// <remarks>This applies to all sitting avatars whether there is a sit target set or not.</remarks>
        /// <returns>A hashset of the sitting avatars.  Returns null if there are no sitting avatars.</returns>
        public HashSet<ScenePresence> GetSittingAvatars()
        {
            lock (ParentGroup.m_sittingAvatars)
            {
                if (m_sittingAvatars == null)
                    return null;
                else
                    return new HashSet<ScenePresence>(m_sittingAvatars);
            }
        }

        /// <summary>
        /// Gets the number of sitting avatars.
        /// </summary>
        /// <remarks>This applies to all sitting avatars whether there is a sit target set or not.</remarks>
        /// <returns></returns>
        public int GetSittingAvatarsCount()
        {
            lock (ParentGroup.m_sittingAvatars)
            {
                if (m_sittingAvatars == null)
                    return 0;
                else
                    return m_sittingAvatars.Count;
            }
        }

        public void Stop()
        {
            Velocity = Vector3.Zero;
            AngularVelocity = Vector3.Zero;
            Acceleration = Vector3.Zero;
            APIDActive = false;
        }

        // handle osVolumeDetect
        public void ScriptSetVolumeDetect(bool makeVolumeDetect)
        {
            if(ParentGroup.IsDeleted)
                return;

            if(_parentID == 0)
            {
                // if root prim do it is like llVolumeDetect
                ParentGroup.ScriptSetVolumeDetect(makeVolumeDetect);
                return;
            }

            if(ParentGroup.IsVolumeDetect)
                return; // entire linkset is phantom already

            bool wasUsingPhysics = ParentGroup.UsesPhysics;
            bool wasTemporary = ParentGroup.IsTemporary;
            bool wasPhantom = ParentGroup.IsPhantom;

            if(PhysActor != null)
                PhysActor.Building = true;
            UpdatePrimFlags(wasUsingPhysics, wasTemporary, wasPhantom, makeVolumeDetect, false);
        }

        protected static int m_animationSequenceNumber = (int)(Util.GetTimeStampTicks() & 0x5fffafL);
        public static int NextObjectAnimationSequenceNumber
        {
            get
            {
                int ret = Interlocked.Increment(ref m_animationSequenceNumber);
                if (ret <= 0)
                {
                    m_animationSequenceNumber = (int)(Util.GetTimeStampTicks() & 0xafff5fL);
                    ret = Interlocked.Increment(ref m_animationSequenceNumber);
                }
                return ret;
            }
        }

        private readonly object animsLock = new object();
        public Dictionary<UUID, int> Animations = null;
        public Dictionary<UUID, string> AnimationsNames = null;

        public bool AddAnimation(UUID animId, string animName)
        {
            if (animId.IsZero() || string.IsNullOrEmpty(animName) ||
                    ParentGroup == null || ParentGroup.IsDeleted || ParentGroup.inTransit)
                return false;

            lock (animsLock)
            {
                Animations ??= new Dictionary<UUID, int>(1);
                AnimationsNames ??= new Dictionary<UUID, string>(1);

                if (Animations.ContainsKey(animId))
                    return false;

                Animations[animId] = NextObjectAnimationSequenceNumber;
                AnimationsNames[animId] = animName;
                ScheduleUpdate(PrimUpdateFlags.Animations);
            }
            return true;
        }

        public bool RemoveAnimation(UUID animId)
        {
            if (animId.IsZero() || ParentGroup == null || ParentGroup.IsDeleted || ParentGroup.inTransit)
                return false;

            lock (animsLock)
            {
                if (Animations == null)
                    return false;

                if (Animations.ContainsKey(animId))
                {
                    Animations.Remove(animId);
                    AnimationsNames?.Remove(animId);
                    ScheduleUpdate(PrimUpdateFlags.Animations);
                    return true;
                }
            }
            return false;
        }

        public bool RemoveAnimation(string anim)
        {
            if (ParentGroup == null || ParentGroup.IsDeleted || ParentGroup.inTransit || string.IsNullOrWhiteSpace(anim))
                return false;

            lock (animsLock)
            {
                if (Animations == null || Animations.Count == 0)
                    return false;

                if (!UUID.TryParse(anim, out UUID animId))
                {
                    if (AnimationsNames == null || AnimationsNames.Count == 0)
                        return false;

                    foreach (KeyValuePair<UUID, string> kvp in AnimationsNames)
                    {
                        if (anim.Equals(kvp.Value, StringComparison.InvariantCultureIgnoreCase))
                        {
                            animId = kvp.Key;
                            break;
                        }
                    }
                }

                if (Animations.ContainsKey(animId))
                {
                    Animations.Remove(animId);
                    AnimationsNames?.Remove(animId);
                    ScheduleUpdate(PrimUpdateFlags.Animations);
                    return true;
                }
            }
            return false;
        }

        public int ClearObjectAnimations()
        {
            int ret = 0;
            if(Animations != null)
            {
                ret = Animations.Count;
                Animations.Clear();
                AnimationsNames.Clear();
            }
            else
            {
                Animations = new Dictionary<UUID, int>();
                AnimationsNames = new Dictionary<UUID, string>();
            }
            ScheduleUpdate(PrimUpdateFlags.Animations);
            return ret;
        }

        public int GetAnimations(out UUID[] ids, out int[] seqs)
        {
            ids = null;
            seqs = null;

            if (ParentGroup == null || ParentGroup.IsDeleted || ParentGroup.inTransit)
                return -1;

            lock (animsLock)
            {
                if (Animations == null)
                    return -1;
                if(Animations.Count == 0)
                    return 0;
                ids = new UUID[Animations.Count];
                Animations.Keys.CopyTo(ids, 0);
                seqs = new int[Animations.Count];
                Animations.Values.CopyTo(seqs, 0);
                return Animations.Count;
            }
        }

        public Byte[] SerializeAnimations()
        {
            if (AnimationsNames == null)
                return null;

            lock (animsLock)
            {
                if (AnimationsNames.Count == 0)
                    return new byte[] { 0 };

                using (MemoryStream ms = new())
                {
                    byte[] tmp = Utils.UInt16ToBytes((ushort)Animations.Count);
                    ms.Write(tmp, 0, 2);

                    foreach(KeyValuePair<UUID,string> kvp in AnimationsNames)
                    {
                        tmp = kvp.Key.GetBytes();
                        ms.Write(tmp, 0, 16);
                        if(string.IsNullOrEmpty(kvp.Value))
                            ms.WriteByte(0);
                        else
                        {
                            byte[] str = Util.StringToBytes(kvp.Value, 64);
                            int len = str.Length - 1;
                            ms.WriteByte((byte)len);
                            ms.Write(str, 0 , len);
                        }
                    }
                    return ms.ToArray();
                }
            }
        }

        public void DeSerializeAnimations(Byte[] data)
        {
            if(data == null)
            {
                Animations = null;
                AnimationsNames = null;
                return;
            }

            if (data.Length < 2)
            {
                Animations = new Dictionary<UUID, int>();
                AnimationsNames = new Dictionary<UUID, string>();
                return;
            }

            try
            {
                int count = (int)Utils.BytesToUInt16(data, 0);
                if(count == 0)
                    return;

                Animations = new Dictionary<UUID, int>(count);
                AnimationsNames = new Dictionary<UUID, string>(count);
                int pos = 2;
                while(--count >= 0)
                {
                    UUID id = new(data, pos);
                    if(id.IsZero())
                        break;
                    pos += 16;
                    int strlen = data[pos++];
                    string name = UTF8Encoding.UTF8.GetString(data, pos, strlen);
                    if(string.IsNullOrEmpty(name))
                        break;
                    pos += strlen;
                    Animations[id] = NextObjectAnimationSequenceNumber;
                    AnimationsNames[id] = name;
                }
                return;
            }
            catch { }

            Animations = null;
            AnimationsNames = null;
        }

        public bool GetOwnerName(out string FirstName, out string LastName)
        {
            if(ParentGroup != null)
                return ParentGroup.GetOwnerName(out FirstName, out LastName);
            FirstName = string.Empty;
            LastName = string.Empty;
            return false;
        }
    }
}