opensim/OpenSim/Region/PhysicsModules/ubOde/ODEMeshWorker.cs

/*
 * AJLDuarte 2012
 */

using System;
using OpenSim.Framework;
using OpenSim.Region.PhysicsModules.SharedBase;
using log4net;
using Nini.Config;
using OpenMetaverse;

namespace OpenSim.Region.PhysicsModule.ubOde
{
    public enum MeshState : byte
    {
        noNeed = 0,

        loadingAsset = 1,

        AssetOK = 0x0f,     // 00001111

        NeedMask = 0x30,    // 00110000
        needMesh = 0x10,    // 00010000
        needAsset = 0x20,   // 00100000

        FailMask = 0xC0,    // 11000000
        AssetFailed = 0x40, // 01000000
        MeshFailed = 0x80,   // 10000000

        MeshNoColide = FailMask | needAsset
    }

    public enum meshWorkerCmnds : byte
    {
        nop = 0,
        addnew,
        changefull,
        changesize,
        changeshapetype,
        getmesh,
    }

    public class ODEPhysRepData
    {
        public PhysicsActor actor;
        public PrimitiveBaseShape pbs;
        public IMesh mesh;

        public Vector3 size;
        public Vector3 OBB;
        public Vector3 OBBOffset;

        public float volume;

        public byte shapetype;
        public bool hasOBB;
        public bool hasMeshVolume;
        public bool isTooSmall;
        public MeshState meshState;
        public UUID? assetID;
        public meshWorkerCmnds comand;
    }

    public class ODEMeshWorker
    {
        private readonly ILog m_log;
        private readonly ODEScene m_scene;
        private readonly IMesher m_mesher;

        public bool meshSculptedPrim = true;
        public float meshSculptLOD = 32;
        public float MeshSculptphysicalLOD = 32;
        public float MinSizeToMeshmerize = 0.1f;

        //private static ObjectJobEngine<ODEPhysRepData> workQueue;
        private ObjectJobEngine workQueue;
        private bool m_running;

        private readonly object m_threadLock = new();

        public ODEMeshWorker(ODEScene pScene, ILog pLog, IMesher pMesher, IConfig pConfig)
        {
            m_scene = pScene;
            m_log = pLog;
            m_mesher = pMesher;

            if (pConfig is not null)
            {
                meshSculptedPrim = pConfig.GetBoolean("mesh_sculpted_prim", meshSculptedPrim);
                meshSculptLOD = pConfig.GetFloat("mesh_lod", meshSculptLOD);
                MinSizeToMeshmerize =  pConfig.GetFloat("mesh_min_size", MinSizeToMeshmerize);
                MeshSculptphysicalLOD = pConfig.GetFloat("mesh_physical_lod", MeshSculptphysicalLOD);
            }
            m_running = true;
            Util.FireAndForget(DoCacheExpire, null, "OdeCacheExpire", false);
            lock(m_threadLock)
            {
                workQueue ??= new ObjectJobEngine(DoWork, "OdeMeshWorker");
            }
        }

        private void DoCacheExpire(object o)
        {
            m_mesher.ExpireFileCache();
        }

        private void Enqueue(ODEPhysRepData rep)
        {
            workQueue.Enqueue(rep);
        }

        private void DoWork(object rep)
        {
            if (m_running && rep is ODEPhysRepData nextRep && m_scene.haveActor(nextRep.actor))
            {
                switch (nextRep.comand)
                {
                    case meshWorkerCmnds.changefull:
                    case meshWorkerCmnds.changeshapetype:
                    case meshWorkerCmnds.changesize:
                        GetMesh(nextRep);
                        if (CreateActorPhysRep(nextRep) && m_scene.haveActor(nextRep.actor))
                            m_scene.AddChange(nextRep.actor, changes.PhysRepData, nextRep);
                        break;
                    case meshWorkerCmnds.getmesh:
                        DoRepDataGetMesh(nextRep);
                        break;
                }
            }
        }

        public void Stop()
        {
            try
            {
                m_running = false;
                workQueue.Dispose();
                workQueue = null;
            }
            catch
            {
            }
        }

        public void ChangeActorPhysRep(PhysicsActor actor, PrimitiveBaseShape pbs,
                                        Vector3 size, byte shapetype)
        {
            ODEPhysRepData repData = new()
            {
                actor = actor,
                pbs = pbs,
                size = size,
                shapetype = shapetype
            };

            CheckMesh(repData);
            CalcVolumeData(repData);
            m_scene.AddChange(actor, changes.PhysRepData, repData);
            return;
        }

        public ODEPhysRepData NewActorPhysRep(PhysicsActor actor, PrimitiveBaseShape pbs,
                                        Vector3 size, byte shapetype)
        {
            ODEPhysRepData repData = new()
            {
                actor = actor,
                pbs = pbs,
                size = size,
                shapetype = shapetype
            };

            CheckMesh(repData);
            CalcVolumeData(repData);
            m_scene.AddChange(actor, changes.AddPhysRep, repData);
            return repData;
        }

        public void RequestMesh(ODEPhysRepData repData)
        {
            repData.mesh = null;

            if (repData.meshState == MeshState.needAsset)
            {
                PrimitiveBaseShape pbs = repData.pbs;

                // check if we got outdated

                if (!pbs.SculptEntry || pbs.SculptTexture.IsZero())
                {
                    repData.meshState = MeshState.noNeed;
                    return;
                }

                repData.assetID = pbs.SculptTexture;
                repData.meshState = MeshState.loadingAsset;

                repData.comand = meshWorkerCmnds.getmesh;
                Enqueue(repData);
            }
        }

        // creates and prepares a mesh to use and calls parameters estimation
        public bool CreateActorPhysRep(ODEPhysRepData repData)
        {
            IMesh mesh = repData.mesh;

            if (mesh is not null)
            {
                mesh.getVertexListAsPtrToFloatArray(out _, out _, out int vertexCount);
                mesh.getIndexListAsPtrToIntArray(out _, out _, out int indexCount);

                if (vertexCount == 0 || indexCount == 0)
                {
                    m_log.WarnFormat("[PHYSICS]: Invalid mesh data on prim {0} mesh UUID {1}",
                        repData.actor.Name, repData.pbs.SculptTexture.ToString());
                    repData.meshState = MeshState.MeshFailed;
                    repData.hasOBB = false;
                    repData.mesh = null;
                    m_scene.mesher.ReleaseMesh(mesh);
                }
                else
                {
                    repData.OBBOffset = mesh.GetCentroid();
                    repData.OBB = mesh.GetOBB();
                    repData.hasOBB = true;
                    mesh.releaseSourceMeshData();
                }
            }
            CalcVolumeData(repData);
            return true;
        }

        public void AssetLoaded(ODEPhysRepData repData)
        {
            if (m_scene.haveActor(repData.actor))
            {
                if (needsMeshing(repData)) // no need for pbs now?
                {
                    repData.comand = meshWorkerCmnds.changefull;
                    Enqueue(repData);
                }
            }
            else
                repData.pbs.SculptData = Array.Empty<byte>();
        }

        public void DoRepDataGetMesh(ODEPhysRepData repData)
        {
            if (!repData.pbs.SculptEntry)
                return;

            if (repData.meshState != MeshState.loadingAsset)
                return;

            if (repData.assetID is null || repData.assetID.Value.IsZero())
                return;

            if (repData.assetID != repData.pbs.SculptTexture)
                return;

            // check if it is in cache
            GetMesh(repData);
            if (repData.meshState != MeshState.needAsset)
            {
                CreateActorPhysRep(repData);
                m_scene.AddChange(repData.actor, changes.PhysRepData, repData);
                return;
            }

            RequestAssetDelegate assetProvider = m_scene.RequestAssetMethod;
            if (assetProvider is null)
                return;
            ODEAssetRequest asr = new(this, assetProvider, repData, m_log);
        }


        /// <summary>
        /// Routine to figure out if we need to mesh this prim with our mesher
        /// </summary>
        /// <param name="pbs"></param>
        /// <returns></returns>
        public bool needsMeshing(ODEPhysRepData repData)
        {
            PrimitiveBaseShape pbs = repData.pbs;
            // check sculpts or meshs

            Vector3 scale = pbs.Scale;
            if(scale.X <= MinSizeToMeshmerize &&
               scale.Y <= MinSizeToMeshmerize &&
               scale.Z <= MinSizeToMeshmerize)
            {
                repData.isTooSmall = true;
                return false;
            }

            if (pbs.SculptEntry)
            {
                if (meshSculptedPrim)
                    return true;

                if (pbs.SculptType == (byte)SculptType.Mesh) // always do meshs
                    return true;

                return false;
            }

            // convex shapes have no holes
            ushort profilehollow = pbs.ProfileHollow;
            if(repData.shapetype == 2)
                profilehollow = 0;

            // if it's a standard box or sphere with no cuts, hollows, twist or top shear, return false since ODE can use an internal representation for the prim

            if ((pbs.ProfileShape == ProfileShape.Square && pbs.PathCurve == (byte)Extrusion.Straight)
                    || (pbs.ProfileShape == ProfileShape.HalfCircle && pbs.PathCurve == (byte)Extrusion.Curve1
                    && pbs.Scale.X == pbs.Scale.Y && pbs.Scale.Y == pbs.Scale.Z))
            {

                if (pbs.ProfileBegin == 0 && pbs.ProfileEnd == 0
                    && profilehollow == 0
                    && pbs.PathTwist == 0 && pbs.PathTwistBegin == 0
                    && pbs.PathBegin == 0 && pbs.PathEnd == 0
                    && pbs.PathTaperX == 0 && pbs.PathTaperY == 0
                    && pbs.PathScaleX == 100 && pbs.PathScaleY == 100
                    && pbs.PathShearX == 0 && pbs.PathShearY == 0)
                {
                    return false;
                }
            }

            //  following code doesn't give meshs to boxes and spheres ever
            // and it's odd..  so for now just return true if asked to force meshs
            // hopefully mesher will fail if doesn't suport so things still get basic boxes

            int iPropertiesNotSupportedDefault = 0;

            if (profilehollow != 0)
                iPropertiesNotSupportedDefault++;

            if ((pbs.PathBegin != 0) || pbs.PathEnd != 0)
                iPropertiesNotSupportedDefault++;

            if ((pbs.PathTwistBegin != 0) || (pbs.PathTwist != 0))
                iPropertiesNotSupportedDefault++;

            if ((pbs.ProfileBegin != 0) || pbs.ProfileEnd != 0)
                iPropertiesNotSupportedDefault++;

            if ((pbs.PathScaleX != 100) || (pbs.PathScaleY != 100))
                iPropertiesNotSupportedDefault++;

            if ((pbs.PathShearX != 0) || (pbs.PathShearY != 0))
                iPropertiesNotSupportedDefault++;

            if (pbs.ProfileShape == ProfileShape.Circle && pbs.PathCurve == (byte)Extrusion.Straight)
                iPropertiesNotSupportedDefault++;

            if (pbs.ProfileShape == ProfileShape.HalfCircle && pbs.PathCurve == (byte)Extrusion.Curve1 && (pbs.Scale.X != pbs.Scale.Y || pbs.Scale.Y != pbs.Scale.Z || pbs.Scale.Z != pbs.Scale.X))
                iPropertiesNotSupportedDefault++;

            if (pbs.ProfileShape == ProfileShape.HalfCircle && pbs.PathCurve == (byte)Extrusion.Curve1)
                iPropertiesNotSupportedDefault++;

            // test for torus
            if ((pbs.ProfileCurve & 0x07) == (byte)ProfileShape.Square)
            {
                if (pbs.PathCurve == (byte)Extrusion.Curve1)
                {
                    iPropertiesNotSupportedDefault++;
                }
            }
            else if ((pbs.ProfileCurve & 0x07) == (byte)ProfileShape.Circle)
            {
                if (pbs.PathCurve == (byte)Extrusion.Straight)
                {
                    iPropertiesNotSupportedDefault++;
                }

                // ProfileCurve seems to combine hole shape and profile curve so we need to only compare against the lower 3 bits
                else if (pbs.PathCurve == (byte)Extrusion.Curve1)
                {
                    iPropertiesNotSupportedDefault++;
                }
            }
            else if ((pbs.ProfileCurve & 0x07) == (byte)ProfileShape.HalfCircle)
            {
                if (pbs.PathCurve == (byte)Extrusion.Curve1 || pbs.PathCurve == (byte)Extrusion.Curve2)
                {
                    iPropertiesNotSupportedDefault++;
                }
            }
            else if ((pbs.ProfileCurve & 0x07) == (byte)ProfileShape.EquilateralTriangle)
            {
                if (pbs.PathCurve == (byte)Extrusion.Straight)
                {
                    iPropertiesNotSupportedDefault++;
                }
                else if (pbs.PathCurve == (byte)Extrusion.Curve1)
                {
                    iPropertiesNotSupportedDefault++;
                }
            }

            if (iPropertiesNotSupportedDefault == 0)
            {
                return false;
            }
            return true;
        }

        // see if we need a mesh and if so if we have a cached one
        // called with a new repData
        public void CheckMesh(ODEPhysRepData repData)
        {
            PhysicsActor actor = repData.actor;
            PrimitiveBaseShape pbs = repData.pbs;

            if (!needsMeshing(repData))
            {
                repData.meshState = MeshState.noNeed;
                repData.hasOBB = false;
                return;
            }

            Vector3 size = repData.size;
            int clod = (int)LevelOfDetail.High;
            byte shapetype = repData.shapetype;
            bool convex = shapetype == 2;

            IMesh mesh = m_mesher.GetMesh(actor.Name, pbs, size, clod, true, convex);

            if (mesh is null)
            {
                if (pbs.SculptEntry)
                {
                    if (pbs.SculptTexture.IsNotZero())
                    {
                        repData.assetID = pbs.SculptTexture;
                        repData.meshState = MeshState.needAsset;
                    }
                    else
                        repData.meshState = MeshState.MeshFailed;

                    return;
                }
                else
                {
                    repData.meshState = MeshState.needMesh;
                    mesh = m_mesher.CreateMesh(actor.Name, pbs, size, clod, true, convex, true);
                    if (mesh is null)
                    {
                        repData.meshState = MeshState.MeshFailed;
                        return;
                    }
                }
            }

            repData.meshState = MeshState.AssetOK;
            repData.mesh = mesh;
            repData.OBB = mesh.GetOBB();
            repData.OBBOffset = mesh.GetCentroid();
            repData.hasOBB = true;

            if (pbs.SculptEntry)
            {
                repData.assetID = pbs.SculptTexture;
            }

            pbs.SculptData = Array.Empty<byte>();
            return ;
        }

        public void GetMesh(ODEPhysRepData repData)
        {
            PhysicsActor actor = repData.actor;

            PrimitiveBaseShape pbs = repData.pbs;

            repData.mesh = null;
            repData.hasOBB = false;

            if (!needsMeshing(repData))
            {
                repData.meshState = MeshState.noNeed;
                return;
            }

            if (repData.meshState == MeshState.MeshFailed)
                return;

            if (pbs.SculptEntry)
            {
                if (repData.meshState == MeshState.AssetFailed)
                {
                    if (pbs.SculptTexture == repData.assetID)
                        return;
                }
            }

            repData.meshState = MeshState.noNeed;

            Vector3 size = repData.size;
            byte shapetype = repData.shapetype;

            bool convex;
            int clod = (int)LevelOfDetail.High;
            if (shapetype == 0)
                convex = false;
            else
            {
                convex = true;
                if (pbs.SculptType != (byte)SculptType.Mesh)
                    clod = (int)LevelOfDetail.Low;
            }

            IMesh mesh = m_mesher.CreateMesh(actor.Name, pbs, size, clod, true, convex, true);

            if (mesh is null)
            {
                if (pbs.SculptEntry)
                {
                    if (pbs.SculptTexture.IsZero())
                        return;

                    repData.assetID = pbs.SculptTexture;

                    if (pbs.SculptData is null || pbs.SculptData.Length == 0)
                    {
                        repData.meshState = MeshState.needAsset;
                        return;
                    }
                }
            }

            repData.mesh = mesh;
            repData.pbs.SculptData = Utils.EmptyBytes;

            if (mesh is null)
            {
                if (pbs.SculptEntry)
                    repData.meshState = MeshState.AssetFailed;
                else
                    repData.meshState = MeshState.MeshFailed;

                return;
            }

            repData.meshState = MeshState.AssetOK;

            return;
        }

        private static void CalculateBasicPrimVolume(ODEPhysRepData repData)
        {
            Vector3 _size = repData.size;

            float volume = _size.X * _size.Y * _size.Z; // default
            if(repData.isTooSmall)
            {
                repData.volume = volume;
                return;
            }

            PrimitiveBaseShape _pbs = repData.pbs;
            float tmp;

            float hollowAmount = ((float)_pbs.ProfileHollow) * 2.0e-5f;
            float hollowVolume = hollowAmount * hollowAmount;

            switch (_pbs.ProfileShape)
            {
                case ProfileShape.Square:
                    // default box

                    if (_pbs.PathCurve == (byte)Extrusion.Straight)
                    {
                        if (hollowAmount > 0.0)
                        {
                            switch (_pbs.HollowShape)
                            {
                                case HollowShape.Square:
                                case HollowShape.Same:
                                    break;

                                case HollowShape.Circle:

                                    hollowVolume *= 0.78539816339f;
                                    break;

                                case HollowShape.Triangle:

                                    hollowVolume *= (0.5f * .5f);
                                    break;

                                default:
                                    hollowVolume = 0;
                                    break;
                            }
                            volume *= (1.0f - hollowVolume);
                        }
                    }

                    else if (_pbs.PathCurve == (byte)Extrusion.Curve1)
                    {
                        //a tube

                        volume *= 0.78539816339e-2f * (float)(200 - _pbs.PathScaleX);
                        tmp = 1.0f - 2.0e-2f * (float)(200 - _pbs.PathScaleY);
                        volume -= volume * tmp * tmp;

                        if (hollowAmount > 0.0)
                        {
                            hollowVolume *= hollowAmount;

                            switch (_pbs.HollowShape)
                            {
                                case HollowShape.Square:
                                case HollowShape.Same:
                                    break;

                                case HollowShape.Circle:
                                    hollowVolume *= 0.78539816339f;
                                    break;

                                case HollowShape.Triangle:
                                    hollowVolume *= 0.5f * 0.5f;
                                    break;
                                default:
                                    hollowVolume = 0;
                                    break;
                            }
                            volume *= (1.0f - hollowVolume);
                        }
                    }

                    break;

                case ProfileShape.Circle:

                    if (_pbs.PathCurve == (byte)Extrusion.Straight)
                    {
                        volume *= 0.78539816339f; // elipse base

                        if (hollowAmount > 0.0)
                        {
                            switch (_pbs.HollowShape)
                            {
                                case HollowShape.Same:
                                case HollowShape.Circle:
                                    break;

                                case HollowShape.Square:
                                    hollowVolume *= 0.5f * 2.5984480504799f;
                                    break;

                                case HollowShape.Triangle:
                                    hollowVolume *= .5f * 1.27323954473516f;
                                    break;

                                default:
                                    hollowVolume = 0;
                                    break;
                            }
                            volume *= (1.0f - hollowVolume);
                        }
                    }

                    else if (_pbs.PathCurve == (byte)Extrusion.Curve1)
                    {
                        volume *= 0.61685027506808491367715568749226e-2f * (float)(200 - _pbs.PathScaleX);
                        tmp = 1.0f - .02f * (float)(200 - _pbs.PathScaleY);
                        volume *= (1.0f - tmp * tmp);

                        if (hollowAmount > 0.0)
                        {

                            // calculate the hollow volume by it's shape compared to the prim shape
                            hollowVolume *= hollowAmount;

                            switch (_pbs.HollowShape)
                            {
                                case HollowShape.Same:
                                case HollowShape.Circle:
                                    break;

                                case HollowShape.Square:
                                    hollowVolume *= 0.5f * 2.5984480504799f;
                                    break;

                                case HollowShape.Triangle:
                                    hollowVolume *= .5f * 1.27323954473516f;
                                    break;

                                default:
                                    hollowVolume = 0;
                                    break;
                            }
                            volume *= (1.0f - hollowVolume);
                        }
                    }
                    break;

                case ProfileShape.HalfCircle:
                    if (_pbs.PathCurve == (byte)Extrusion.Curve1)
                    {
                        volume *= 0.5236f;

                        if (hollowAmount > 0.0)
                        {
                            hollowVolume *= hollowAmount;

                            switch (_pbs.HollowShape)
                            {
                                case HollowShape.Circle:
                                case HollowShape.Triangle:  // diference in sl is minor and odd
                                case HollowShape.Same:
                                    break;

                                case HollowShape.Square:
                                    hollowVolume *= 0.909f;
                                    break;

                                //case HollowShape.Triangle:
                                //    hollowVolume *= .827f;
                                //    break;
                                default:
                                    hollowVolume = 0;
                                    break;
                            }
                            volume *= (1.0f - hollowVolume);
                        }

                    }
                    break;

                case ProfileShape.EquilateralTriangle:

                    if (_pbs.PathCurve == (byte)Extrusion.Straight)
                    {
                        volume *= 0.32475953f;

                        if (hollowAmount > 0.0)
                        {

                            // calculate the hollow volume by it's shape compared to the prim shape
                            switch (_pbs.HollowShape)
                            {
                                case HollowShape.Same:
                                case HollowShape.Triangle:
                                    hollowVolume *= .25f;
                                    break;

                                case HollowShape.Square:
                                    hollowVolume *= 0.499849f * 3.07920140172638f;
                                    break;

                                case HollowShape.Circle:
                                    // Hollow shape is a perfect cyllinder in respect to the cube's scale
                                    // Cyllinder hollow volume calculation

                                    hollowVolume *= 0.1963495f * 3.07920140172638f;
                                    break;

                                default:
                                    hollowVolume = 0;
                                    break;
                            }
                            volume *= (1.0f - hollowVolume);
                        }
                    }
                    else if (_pbs.PathCurve == (byte)Extrusion.Curve1)
                    {
                        volume *= 0.32475953f;
                        volume *= 0.01f * (float)(200 - _pbs.PathScaleX);
                        tmp = 1.0f - .02f * (float)(200 - _pbs.PathScaleY);
                        volume *= (1.0f - tmp * tmp);

                        if (hollowAmount > 0.0)
                        {

                            hollowVolume *= hollowAmount;

                            switch (_pbs.HollowShape)
                            {
                                case HollowShape.Same:
                                case HollowShape.Triangle:
                                    hollowVolume *= .25f;
                                    break;

                                case HollowShape.Square:
                                    hollowVolume *= 0.499849f * 3.07920140172638f;
                                    break;

                                case HollowShape.Circle:

                                    hollowVolume *= 0.1963495f * 3.07920140172638f;
                                    break;

                                default:
                                    hollowVolume = 0;
                                    break;
                            }
                            volume *= (1.0f - hollowVolume);
                        }
                    }
                    break;

                default:
                    break;
            }

            float taperX1;
            float taperY1;
            float taperX;
            float taperY;
            float pathBegin;
            float pathEnd;
            float profileBegin;
            float profileEnd;

            if (_pbs.PathCurve == (byte)Extrusion.Straight || _pbs.PathCurve == (byte)Extrusion.Flexible)
            {
                taperX1 = _pbs.PathScaleX * 0.01f;
                if (taperX1 > 1.0f)
                    taperX1 = 2.0f - taperX1;
                taperX = 1.0f - taperX1;

                taperY1 = _pbs.PathScaleY * 0.01f;
                if (taperY1 > 1.0f)
                    taperY1 = 2.0f - taperY1;
                taperY = 1.0f - taperY1;
            }
            else
            {
                taperX = _pbs.PathTaperX * 0.01f;
                if (taperX < 0.0f)
                    taperX = -taperX;
                taperX1 = 1.0f - taperX;

                taperY = _pbs.PathTaperY * 0.01f;
                if (taperY < 0.0f)
                    taperY = -taperY;
                taperY1 = 1.0f - taperY;
            }

            volume *= (taperX1 * taperY1 + 0.5f * (taperX1 * taperY + taperX * taperY1) + 0.3333333333f * taperX * taperY);

            pathBegin = (float)_pbs.PathBegin * 2.0e-5f;
            pathEnd = 1.0f - (float)_pbs.PathEnd * 2.0e-5f;
            volume *= (pathEnd - pathBegin);

            // this is crude aproximation
            profileBegin = (float)_pbs.ProfileBegin * 2.0e-5f;
            profileEnd = 1.0f - (float)_pbs.ProfileEnd * 2.0e-5f;
            volume *= (profileEnd - profileBegin);

            repData.volume = volume;
        }

        private static void CalcVolumeData(ODEPhysRepData repData)
        {
            if (!repData.hasOBB)
            {
                repData.OBB = repData.size * 0.5f;
                repData.OBBOffset = Vector3.Zero;
            }

            CalculateBasicPrimVolume(repData);
        }
    }

    public class ODEAssetRequest
    {
        private readonly ODEMeshWorker m_worker;
        private readonly ILog m_log;
        private readonly ODEPhysRepData repData;

        public ODEAssetRequest(ODEMeshWorker pWorker, RequestAssetDelegate provider,
            ODEPhysRepData pRepData, ILog plog)
        {
            m_worker = pWorker;
            m_log = plog;
            repData = pRepData;

            repData.meshState = MeshState.loadingAsset;
            provider((UUID)repData.assetID, ODEassetReceived);
        }

        void ODEassetReceived(AssetBase asset)
        {
            repData.meshState = MeshState.AssetFailed;
            if (asset is not null)
            {
                if (asset.Data is not null && asset.Data.Length > 0)
                {
                    repData.meshState = MeshState.noNeed;

                    if (!repData.pbs.SculptEntry)
                        return;
                    if (repData.pbs.SculptTexture != repData.assetID)
                        return;

                    //repData.pbs.SculptData = new byte[asset.Data.Length];
                    //asset.Data.CopyTo(repData.pbs.SculptData,0);
                    repData.pbs.SculptData = asset.Data;
                    repData.meshState = MeshState.AssetOK;
                    m_worker.AssetLoaded(repData);
                }
                else
                    m_log.WarnFormat("[PHYSICS]: asset provider returned invalid mesh data for prim {0} asset UUID {1}.",
                        repData.actor.Name, asset.ID.ToString());
            }
            else
                m_log.WarnFormat("[PHYSICS]: asset provider returned null asset for mesh of prim {0}.",
                    repData.actor.Name);
        }
    }
}