// This is the standard Near.   Uses space AABBs to speed up detection.
        private void near(IntPtr space, IntPtr g1, IntPtr g2)
        {

            //Don't test against heightfield Geom, or you'll be sorry!
            
            /*
             terminate called after throwing an instance of 'std::bad_alloc'
                  what():  std::bad_alloc
                Stacktrace:
                 
                  at (wrapper managed-to-native) Ode.NET.d.Collide (intptr,intptr,int,Ode.NET.d/ContactGeom[],int) <0x00004>
                  at (wrapper managed-to-native) Ode.NET.d.Collide (intptr,intptr,int,Ode.NET.d/ContactGeom[],int) <0xffffffff>
                  at OpenSim.Region.Physics.OdePlugin.ODERayCastRequestManager.near (intptr,intptr,intptr) <0x00280>
                  at (wrapper native-to-managed) OpenSim.Region.Physics.OdePlugin.ODERayCastRequestManager.near (intptr,intptr,intptr) <0xfff
                fffff>
                  at (wrapper managed-to-native) Ode.NET.d.SpaceCollide2 (intptr,intptr,intptr,Ode.NET.d/NearCallback) <0x00004>
                  at (wrapper managed-to-native) Ode.NET.d.SpaceCollide2 (intptr,intptr,intptr,Ode.NET.d/NearCallback) <0xffffffff>
                  at OpenSim.Region.Physics.OdePlugin.ODERayCastRequestManager.RayCast (OpenSim.Region.Physics.OdePlugin.ODERayCastRequest) <
                0x00114>
                  at OpenSim.Region.Physics.OdePlugin.ODERayCastRequestManager.ProcessQueuedRequests () <0x000eb>
                  at OpenSim.Region.Physics.OdePlugin.OdeScene.Simulate (single) <0x017e6>
                  at OpenSim.Region.Framework.Scenes.SceneGraph.UpdatePhysics (double) <0x00042>
                  at OpenSim.Region.Framework.Scenes.Scene.Update () <0x0039e>
                  at OpenSim.Region.Framework.Scenes.Scene.Heartbeat (object) <0x00019>
                  at (wrapper runtime-invoke) object.runtime_invoke_void__this___object (object,intptr,intptr,intptr) <0xffffffff>
                 
                Native stacktrace:
                 
                        mono [0x80d2a42]
                        [0xb7f5840c]
                        /lib/i686/cmov/libc.so.6(abort+0x188) [0xb7d1a018]
                        /usr/lib/libstdc++.so.6(_ZN9__gnu_cxx27__verbose_terminate_handlerEv+0x158) [0xb45fc988]
                        /usr/lib/libstdc++.so.6 [0xb45fa865]
                        /usr/lib/libstdc++.so.6 [0xb45fa8a2]
                        /usr/lib/libstdc++.so.6 [0xb45fa9da]
                        /usr/lib/libstdc++.so.6(_Znwj+0x83) [0xb45fb033]
                        /usr/lib/libstdc++.so.6(_Znaj+0x1d) [0xb45fb11d]
                        libode.so(_ZN13dxHeightfield23dCollideHeightfieldZoneEiiiiP6dxGeomiiP12dContactGeomi+0xd04) [0xb46678e4]
                        libode.so(_Z19dCollideHeightfieldP6dxGeomS0_iP12dContactGeomi+0x54b) [0xb466832b]
                        libode.so(dCollide+0x102) [0xb46571b2]
                        [0x95cfdec9]
                        [0x8ea07fe1]
                        [0xab260146]
                        libode.so [0xb465a5c4]
                        libode.so(_ZN11dxHashSpace8collide2EPvP6dxGeomPFvS0_S2_S2_E+0x75) [0xb465bcf5]
                        libode.so(dSpaceCollide2+0x177) [0xb465ac67]
                        [0x95cf978e]
                        [0x8ea07945]
                        [0x95cf2bbc]
                        [0xab2787e7]
                        [0xab419fb3]
                        [0xab416657]
                        [0xab415bda]
                        [0xb609b08e]
                        mono(mono_runtime_delegate_invoke+0x34) [0x8192534]
                        mono [0x81a2f0f]
                        mono [0x81d28b6]
                        mono [0x81ea2c6]
                        /lib/i686/cmov/libpthread.so.0 [0xb7e744c0]
                        /lib/i686/cmov/libc.so.6(clone+0x5e) [0xb7dcd6de]
             */

            // Exclude heightfield geom

            if (g1 == IntPtr.Zero || g2 == IntPtr.Zero)
                return;
            if (d.GeomGetClass(g1) == d.GeomClassID.HeightfieldClass || d.GeomGetClass(g2) == d.GeomClassID.HeightfieldClass)
                return;

            // Raytest against AABBs of spaces first, then dig into the spaces it hits for actual geoms.
            if (d.GeomIsSpace(g1) || d.GeomIsSpace(g2))
            {
                if (g1 == IntPtr.Zero || g2 == IntPtr.Zero)
                    return;
                
                // Separating static prim geometry spaces.
                // We'll be calling near recursivly if one
                // of them is a space to find all of the
                // contact points in the space
                try
                {
                    d.SpaceCollide2(g1, g2, IntPtr.Zero, nearCallback);
                }
                catch (AccessViolationException)
                {
                    m_log.Warn("[PHYSICS]: Unable to collide test a space");
                    return;
                }
                //Colliding a space or a geom with a space or a geom. so drill down

                //Collide all geoms in each space..
                //if (d.GeomIsSpace(g1)) d.SpaceCollide(g1, IntPtr.Zero, nearCallback);
                //if (d.GeomIsSpace(g2)) d.SpaceCollide(g2, IntPtr.Zero, nearCallback);
                return;
            }

            if (g1 == IntPtr.Zero || g2 == IntPtr.Zero)
                return;

            int count = 0;
            try
            {
                
                if (g1 == g2)
                    return; // Can't collide with yourself

                lock (contacts)
                {
                    count = d.Collide(g1, g2, contacts.GetLength(0), contacts, d.ContactGeom.SizeOf);
                }
            }
            catch (SEHException)
            {
                m_log.Error("[PHYSICS]: The Operating system shut down ODE because of corrupt memory.  This could be a result of really irregular terrain.  If this repeats continuously, restart using Basic Physics and terrain fill your terrain.  Restarting the sim.");
            }
            catch (Exception e)
            {
                m_log.WarnFormat("[PHYSICS]: Unable to collide test an object: {0}", e.Message);
                return;
            }

            PhysicsActor p1 = null;
            PhysicsActor p2 = null;

            if (g1 != IntPtr.Zero)
                m_scene.actor_name_map.TryGetValue(g1, out p1);

            if (g2 != IntPtr.Zero)
                m_scene.actor_name_map.TryGetValue(g1, out p2);

            // Loop over contacts, build results.
            for (int i = 0; i < count; i++)
            {
                if (p1 != null)
                {
                    if (p1 is OdePrim)
                    {
                        ContactResult collisionresult = new ContactResult();
                    
                        collisionresult.ConsumerID = p1.LocalID;
                        collisionresult.Pos = new Vector3(contacts[i].pos.X, contacts[i].pos.Y, contacts[i].pos.Z);
                        collisionresult.Depth = contacts[i].depth;
                        collisionresult.Normal = new Vector3(contacts[i].normal.X, contacts[i].normal.Y,
                                                             contacts[i].normal.Z);
                        lock (m_contactResults)
                            m_contactResults.Add(collisionresult);
                    }
                }

                if (p2 != null)
                {
                    if (p2 is OdePrim)
                    {
                        ContactResult collisionresult = new ContactResult();

                        collisionresult.ConsumerID = p2.LocalID;
                        collisionresult.Pos = new Vector3(contacts[i].pos.X, contacts[i].pos.Y, contacts[i].pos.Z);
                        collisionresult.Depth = contacts[i].depth;
                        collisionresult.Normal = new Vector3(contacts[i].normal.X, contacts[i].normal.Y,
                                      contacts[i].normal.Z);

                        lock (m_contactResults)
                            m_contactResults.Add(collisionresult);
                    }
                }
            }
        }
        // This is the standard Near.   Uses space AABBs to speed up detection.
        private void near(IntPtr space, IntPtr g1, IntPtr g2)
        {

            if (g1 == IntPtr.Zero || g2 == IntPtr.Zero)
                return;
//            if (d.GeomGetClass(g1) == d.GeomClassID.HeightfieldClass || d.GeomGetClass(g2) == d.GeomClassID.HeightfieldClass)
//                return;

            // Raytest against AABBs of spaces first, then dig into the spaces it hits for actual geoms.
            if (d.GeomIsSpace(g1) || d.GeomIsSpace(g2))
            {
                if (g1 == IntPtr.Zero || g2 == IntPtr.Zero)
                    return;
                
                // Separating static prim geometry spaces.
                // We'll be calling near recursivly if one
                // of them is a space to find all of the
                // contact points in the space
                try
                {
                    d.SpaceCollide2(g1, g2, IntPtr.Zero, nearCallback);
                }
                catch (AccessViolationException)
                {
                    m_log.Warn("[PHYSICS]: Unable to collide test a space");
                    return;
                }
                //Colliding a space or a geom with a space or a geom. so drill down

                //Collide all geoms in each space..
                //if (d.GeomIsSpace(g1)) d.SpaceCollide(g1, IntPtr.Zero, nearCallback);
                //if (d.GeomIsSpace(g2)) d.SpaceCollide(g2, IntPtr.Zero, nearCallback);
                return;
            }

            if (g1 == IntPtr.Zero || g2 == IntPtr.Zero)
                return;

            int count = 0;
            try
            {
                
                if (g1 == g2)
                    return; // Can't collide with yourself

                lock (contacts)
                {
                    count = d.Collide(g1, g2, contacts.GetLength(0), contacts, d.ContactGeom.unmanagedSizeOf);
                }
            }
            catch (SEHException)
            {
                m_log.Error("[PHYSICS]: The Operating system shut down ODE because of corrupt memory.  This could be a result of really irregular terrain.  If this repeats continuously, restart using Basic Physics and terrain fill your terrain.  Restarting the sim.");
            }
            catch (Exception e)
            {
                m_log.WarnFormat("[PHYSICS]: Unable to collide test an object: {0}", e.Message);
                return;
            }

            PhysicsActor p1 = null;
            PhysicsActor p2 = null;

            if (g1 != IntPtr.Zero)
                m_scene.actor_name_map.TryGetValue(g1, out p1);

            if (g2 != IntPtr.Zero)
                m_scene.actor_name_map.TryGetValue(g1, out p2);

            // Loop over contacts, build results.
            for (int i = 0; i < count; i++)
            {
                if (p1 != null)
                {
                    if (p1 is OdePrim)
                    {
                        ContactResult collisionresult = new ContactResult();
                    
                        collisionresult.ConsumerID = p1.LocalID;
                        collisionresult.Pos = new Vector3(contacts[i].pos.X, contacts[i].pos.Y, contacts[i].pos.Z);
                        collisionresult.Depth = contacts[i].depth;
                        collisionresult.Normal = new Vector3(contacts[i].normal.X, contacts[i].normal.Y,
                                                             contacts[i].normal.Z);
                        lock (m_contactResults)
                            m_contactResults.Add(collisionresult);
                    }
                }

                if (p2 != null)
                {
                    if (p2 is OdePrim)
                    {
                        ContactResult collisionresult = new ContactResult();

                        collisionresult.ConsumerID = p2.LocalID;
                        collisionresult.Pos = new Vector3(contacts[i].pos.X, contacts[i].pos.Y, contacts[i].pos.Z);
                        collisionresult.Depth = contacts[i].depth;
                        collisionresult.Normal = new Vector3(contacts[i].normal.X, contacts[i].normal.Y,
                                      contacts[i].normal.Z);

                        lock (m_contactResults)
                            m_contactResults.Add(collisionresult);
                    }
                }
            }
        }