6 files changed, 531 insertions, 46 deletions

diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
index bf4d60c..77658ef 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs
@@ -5010,6 +5010,47 @@ namespace OpenSim.Region.Framework.Scenes
             return Ptot;
         }
 
+        public void GetInertiaData(out float TotalMass, out Vector3 CenterOfMass, out Vector3 Inertia, out Vector4 aux )
+        {
+            PhysicsActor pa = RootPart.PhysActor;
+
+            if(((RootPart.Flags & PrimFlags.Physics) !=0) && pa !=null)
+            {
+                PhysicsInertiaData inertia;
+
+                inertia = pa.GetInertiaData();
+
+                TotalMass = inertia.TotalMass;
+                CenterOfMass = inertia.CenterOfMass;
+                Inertia = inertia.Inertia;
+                aux = inertia.InertiaRotation;
+
+                return;
+            }
+
+            TotalMass = GetMass();
+            CenterOfMass = GetCenterOfMass() - AbsolutePosition;
+            CenterOfMass *= Quaternion.Conjugate(RootPart.RotationOffset);
+            Inertia = Vector3.Zero;
+            aux =  Vector4.Zero;
+        }
+
+        public void SetInertiaData(float TotalMass, Vector3 CenterOfMass, Vector3 Inertia, Vector4 aux )
+        {
+            PhysicsActor pa = RootPart.PhysActor;
+
+            if(pa !=null)
+            {
+                PhysicsInertiaData inertia = new PhysicsInertiaData();
+                inertia.TotalMass = TotalMass;
+                inertia.CenterOfMass = CenterOfMass;
+                inertia.Inertia = Inertia;
+                inertia.InertiaRotation = aux;
+                pa.SetInertiaData(inertia);
+            }
+        }
+
+
         /// <summary>
         /// Set the user group to which this scene object belongs.
         /// </summary>
diff --git a/OpenSim/Region/PhysicsModules/SharedBase/PhysicsActor.cs b/OpenSim/Region/PhysicsModules/SharedBase/PhysicsActor.cs
index 33f0337..ad9b28f 100644
--- a/OpenSim/Region/PhysicsModules/SharedBase/PhysicsActor.cs
+++ b/OpenSim/Region/PhysicsModules/SharedBase/PhysicsActor.cs
@@ -55,6 +55,28 @@ namespace OpenSim.Region.PhysicsModules.SharedBase
         Absolute
     }
 
+    public class PhysicsInertiaData
+    {
+        public float TotalMass; // the total mass of a linkset
+        public Vector3 CenterOfMass;  // the center of mass position relative to root part position
+        public Vector3 Inertia; //  (Ixx, Iyy, Izz) moment of inertia relative to center of mass and principal axis in local coords
+        public Vector4 InertiaRotation; // if principal axis don't match local axis, the principal axis rotation
+                                        // or the upper triangle of the inertia tensor 
+                                        // Ixy (= Iyx), Ixz (= Izx), Iyz (= Izy))
+
+        public PhysicsInertiaData()
+        {
+        }
+
+        public PhysicsInertiaData(PhysicsInertiaData source)
+        {
+           TotalMass = source.TotalMass;
+           CenterOfMass = source.CenterOfMass;
+           Inertia = source.Inertia;
+           InertiaRotation = source.InertiaRotation;
+        }
+    }
+
     public struct CameraData
     {
         public Quaternion CameraRotation;
@@ -463,6 +485,20 @@ namespace OpenSim.Region.PhysicsModules.SharedBase
 
         public virtual void AddCollisionEvent(uint CollidedWith, ContactPoint contact) { }
 
+        public virtual PhysicsInertiaData GetInertiaData()
+        {
+            PhysicsInertiaData data = new PhysicsInertiaData();
+            data.TotalMass = this.Mass;
+            data.CenterOfMass = CenterOfMass - Position;
+            data.Inertia = Vector3.Zero;
+            data.InertiaRotation = Vector4.Zero;
+            return data;
+        }
+
+        public virtual void SetInertiaData(PhysicsInertiaData inertia)
+        {
+        }
+
         // Warning in a parent part it returns itself, not null
         public virtual PhysicsActor ParentActor { get { return this; } }
 
diff --git a/OpenSim/Region/PhysicsModules/ubOde/ODEPrim.cs b/OpenSim/Region/PhysicsModules/ubOde/ODEPrim.cs
index 45ef273..d560b41 100644
--- a/OpenSim/Region/PhysicsModules/ubOde/ODEPrim.cs
+++ b/OpenSim/Region/PhysicsModules/ubOde/ODEPrim.cs
@@ -182,14 +182,16 @@ namespace OpenSim.Region.PhysicsModule.ubOde
         private float m_streamCost;
 
         public d.Mass primdMass; // prim inertia information on it's own referencial
+        private PhysicsInertiaData m_InertiaOverride;
         float primMass; // prim own mass
         float primVolume; // prim own volume;
-        float _mass; // object mass acording to case
+        float m_mass; // object mass acording to case
 
         public int givefakepos;
         private Vector3 fakepos;
         public int givefakeori;
         private Quaternion fakeori;
+        private PhysicsInertiaData m_fakeInertiaOverride;
 
         private int m_eventsubscription;
         private int m_cureventsubscription;
@@ -465,10 +467,110 @@ namespace OpenSim.Region.PhysicsModule.ubOde
             }
         }
 
+        public override PhysicsInertiaData GetInertiaData()
+        {
+            PhysicsInertiaData inertia;
+            if(childPrim)
+            {
+                if(_parent != null)
+                    return _parent.GetInertiaData();
+                else
+                {
+                    inertia = new PhysicsInertiaData();
+                    inertia.TotalMass = -1;
+                    return inertia;
+                }
+            }
+
+            inertia = new PhysicsInertiaData();
+
+            // double buffering
+            if(m_fakeInertiaOverride != null)
+            { 
+                d.Mass objdmass = new d.Mass();
+                objdmass.I.M00 = m_fakeInertiaOverride.Inertia.X;
+                objdmass.I.M11 = m_fakeInertiaOverride.Inertia.Y;
+                objdmass.I.M22 = m_fakeInertiaOverride.Inertia.Z;
+
+                objdmass.mass = m_fakeInertiaOverride.TotalMass;
+                    
+                if(Math.Abs(m_fakeInertiaOverride.InertiaRotation.W) < 0.999)
+                {
+                    d.Matrix3 inertiarotmat = new d.Matrix3();
+                    d.Quaternion inertiarot = new d.Quaternion();
+
+                    inertiarot.X = m_fakeInertiaOverride.InertiaRotation.X;
+                    inertiarot.Y = m_fakeInertiaOverride.InertiaRotation.Y;
+                    inertiarot.Z = m_fakeInertiaOverride.InertiaRotation.Z;
+                    inertiarot.W = m_fakeInertiaOverride.InertiaRotation.W;
+                    d.RfromQ(out inertiarotmat, ref inertiarot);
+                    d.MassRotate(ref objdmass, ref inertiarotmat);
+                }
+
+                inertia.TotalMass = m_fakeInertiaOverride.TotalMass;
+                inertia.CenterOfMass = m_fakeInertiaOverride.CenterOfMass;
+                inertia.Inertia.X = objdmass.I.M00;
+                inertia.Inertia.Y = objdmass.I.M11;
+                inertia.Inertia.Z = objdmass.I.M22;
+                inertia.InertiaRotation.X =  objdmass.I.M01;
+                inertia.InertiaRotation.Y =  objdmass.I.M02;
+                inertia.InertiaRotation.Z =  objdmass.I.M12;
+                return inertia;
+            }
+
+            inertia.TotalMass = m_mass;
+
+            if(Body == IntPtr.Zero || prim_geom == IntPtr.Zero)
+            {
+                inertia.CenterOfMass = Vector3.Zero;
+                inertia.Inertia = Vector3.Zero;
+                inertia.InertiaRotation =  Vector4.Zero;
+                return inertia;
+            }
+
+            d.Vector3 dtmp;
+            d.Mass m = new d.Mass();
+            lock(_parent_scene.OdeLock)
+            {
+                d.AllocateODEDataForThread(0);
+                dtmp = d.GeomGetOffsetPosition(prim_geom);
+                d.BodyGetMass(Body, out m);
+            }
+
+            Vector3 cm = new Vector3(-dtmp.X, -dtmp.Y, -dtmp.Z);
+            inertia.CenterOfMass = cm;
+            inertia.Inertia = new Vector3(m.I.M00, m.I.M11, m.I.M22);
+            inertia.InertiaRotation = new Vector4(m.I.M01, m.I.M02 , m.I.M12, 0);
+
+            return inertia;
+        }
+
+        public override void SetInertiaData(PhysicsInertiaData inertia)
+        {
+            if(childPrim)
+            {
+                if(_parent != null)
+                    _parent.SetInertiaData(inertia);
+                return;
+            }
+
+            if(inertia.TotalMass > 0)
+                m_fakeInertiaOverride = new PhysicsInertiaData(inertia);
+            else
+                m_fakeInertiaOverride = null;
+
+            if (inertia.TotalMass > _parent_scene.maximumMassObject)
+                inertia.TotalMass = _parent_scene.maximumMassObject;
+            AddChange(changes.SetInertia,(object)m_fakeInertiaOverride);
+        }
+
         public override Vector3 CenterOfMass
         {
             get
             {
+                if(!childPrim && m_fakeInertiaOverride != null)
+                    return m_fakeInertiaOverride.CenterOfMass;
+
                 lock (_parent_scene.OdeLock)
                 {
                     d.AllocateODEDataForThread(0);
@@ -922,8 +1024,8 @@ namespace OpenSim.Region.PhysicsModule.ubOde
             {
                 float old = m_density;
                 m_density = value / 100f;
-                if(m_density != old)
-                    UpdatePrimBodyData();
+ //               if(m_density != old)
+ //                   UpdatePrimBodyData();
             }
         }
         public override float GravModifier
@@ -1716,26 +1818,29 @@ namespace OpenSim.Region.PhysicsModule.ubOde
                 m_log.Warn("[PHYSICS]: MakeBody root geom already had a body");
             }
 
-            d.Matrix3 mymat = new d.Matrix3();
-            d.Quaternion myrot = new d.Quaternion();
-            d.Mass objdmass = new d.Mass { };
+            bool noInertiaOverride = (m_InertiaOverride == null);
 
             Body = d.BodyCreate(_parent_scene.world);
 
-            objdmass = primdMass;
+            d.Matrix3 mymat = new d.Matrix3();
+            d.Quaternion myrot = new d.Quaternion();
+            d.Mass objdmass = new d.Mass { };
 
-            // rotate inertia
             myrot.X = _orientation.X;
             myrot.Y = _orientation.Y;
             myrot.Z = _orientation.Z;
             myrot.W = _orientation.W;
-
             d.RfromQ(out mymat, ref myrot);
-            d.MassRotate(ref objdmass, ref mymat);
 
             // set the body rotation
             d.BodySetRotation(Body, ref mymat);
 
+            if(noInertiaOverride)
+            {
+                objdmass = primdMass;
+                d.MassRotate(ref objdmass, ref mymat);
+            }
+    
             // recompute full object inertia if needed
             if (childrenPrim.Count > 0)
             {
@@ -1758,27 +1863,12 @@ namespace OpenSim.Region.PhysicsModule.ubOde
                             continue;
                         }
 
-                        tmpdmass = prm.primdMass;
-
-                        // apply prim current rotation to inertia
                         quat.X = prm._orientation.X;
                         quat.Y = prm._orientation.Y;
                         quat.Z = prm._orientation.Z;
                         quat.W = prm._orientation.W;
                         d.RfromQ(out mat, ref quat);
-                        d.MassRotate(ref tmpdmass, ref mat);
-
-                        Vector3 ppos = prm._position;
-                        ppos.X -= rcm.X;
-                        ppos.Y -= rcm.Y;
-                        ppos.Z -= rcm.Z;
-                        // refer inertia to root prim center of mass position
-                        d.MassTranslate(ref tmpdmass,
-                            ppos.X,
-                            ppos.Y,
-                            ppos.Z);
-
-                        d.MassAdd(ref objdmass, ref tmpdmass); // add to total object inertia
+
                         // fix prim colision cats
 
                         if (d.GeomGetBody(prm.prim_geom) != IntPtr.Zero)
@@ -1791,6 +1881,24 @@ namespace OpenSim.Region.PhysicsModule.ubOde
                         d.GeomSetBody(prm.prim_geom, Body);
                         prm.Body = Body;
                         d.GeomSetOffsetWorldRotation(prm.prim_geom, ref mat); // set relative rotation
+
+                        if(noInertiaOverride)
+                        {
+                            tmpdmass = prm.primdMass;
+
+                            d.MassRotate(ref tmpdmass, ref mat);
+                            Vector3 ppos = prm._position;
+                            ppos.X -= rcm.X;
+                            ppos.Y -= rcm.Y;
+                            ppos.Z -= rcm.Z;
+                            // refer inertia to root prim center of mass position
+                            d.MassTranslate(ref tmpdmass,
+                                ppos.X,
+                                ppos.Y,
+                                ppos.Z);
+
+                            d.MassAdd(ref objdmass, ref tmpdmass); // add to total object inertia
+                        }
                     }
                 }
             }
@@ -1799,19 +1907,60 @@ namespace OpenSim.Region.PhysicsModule.ubOde
             // associate root geom with body
             d.GeomSetBody(prim_geom, Body);
 
-            d.BodySetPosition(Body, _position.X + objdmass.c.X, _position.Y + objdmass.c.Y, _position.Z + objdmass.c.Z);
+            if(noInertiaOverride)
+                d.BodySetPosition(Body, _position.X + objdmass.c.X, _position.Y + objdmass.c.Y, _position.Z + objdmass.c.Z);
+            else
+            {
+                Vector3 ncm =  m_InertiaOverride.CenterOfMass * _orientation;
+                d.BodySetPosition(Body,
+                    _position.X + ncm.X,
+                    _position.Y + ncm.Y,
+                    _position.Z + ncm.Z);
+            }
+
             d.GeomSetOffsetWorldPosition(prim_geom, _position.X, _position.Y, _position.Z);
 
-            d.MassTranslate(ref objdmass, -objdmass.c.X, -objdmass.c.Y, -objdmass.c.Z); // ode wants inertia at center of body
-            myrot.X = -myrot.X;
-            myrot.Y = -myrot.Y;
-            myrot.Z = -myrot.Z;
+            if(noInertiaOverride)
+            {
+                d.MassTranslate(ref objdmass, -objdmass.c.X, -objdmass.c.Y, -objdmass.c.Z); // ode wants inertia at center of body
+                myrot.X = -myrot.X;
+                myrot.Y = -myrot.Y;
+                myrot.Z = -myrot.Z;
 
-            d.RfromQ(out mymat, ref myrot);
-            d.MassRotate(ref objdmass, ref mymat);
+                d.RfromQ(out mymat, ref myrot);
+                d.MassRotate(ref objdmass, ref mymat);
 
-            d.BodySetMass(Body, ref objdmass);
-            _mass = objdmass.mass;
+                d.BodySetMass(Body, ref objdmass);
+                m_mass = objdmass.mass;
+            }
+            else
+            {
+                objdmass.c.X = 0;
+                objdmass.c.Y = 0;
+                objdmass.c.Z = 0;
+
+                objdmass.I.M00 = m_InertiaOverride.Inertia.X;
+                objdmass.I.M11 = m_InertiaOverride.Inertia.Y;
+                objdmass.I.M22 = m_InertiaOverride.Inertia.Z;
+
+                objdmass.mass = m_InertiaOverride.TotalMass;
+
+                if(Math.Abs(m_InertiaOverride.InertiaRotation.W) < 0.999)
+                {
+                    d.Matrix3 inertiarotmat = new d.Matrix3();
+                    d.Quaternion inertiarot = new d.Quaternion();
+
+                    inertiarot.X = m_InertiaOverride.InertiaRotation.X;
+                    inertiarot.Y = m_InertiaOverride.InertiaRotation.Y;
+                    inertiarot.Z = m_InertiaOverride.InertiaRotation.Z;
+                    inertiarot.W = m_InertiaOverride.InertiaRotation.W;
+                    d.RfromQ(out inertiarotmat, ref inertiarot);
+                    d.MassRotate(ref objdmass, ref inertiarotmat);
+                }
+                d.BodySetMass(Body, ref objdmass);
+
+                m_mass = objdmass.mass;
+            }
 
             // disconnect from world gravity so we can apply buoyancy
             d.BodySetGravityMode(Body, false);
@@ -1990,7 +2139,7 @@ namespace OpenSim.Region.PhysicsModule.ubOde
                                 SetInStaticSpace(prm);
                             }
                             prm.Body = IntPtr.Zero;
-                            prm._mass = prm.primMass;
+                            prm.m_mass = prm.primMass;
                             prm.m_collisionscore = 0;
                         }
                     }
@@ -2004,7 +2153,7 @@ namespace OpenSim.Region.PhysicsModule.ubOde
                 }
                 Body = IntPtr.Zero;
             }
-            _mass = primMass;
+            m_mass = primMass;
             m_collisionscore = 0;
         }
 
@@ -2081,7 +2230,7 @@ namespace OpenSim.Region.PhysicsModule.ubOde
             d.BodySetPosition(Body, dobjpos.X + thispos.X, dobjpos.Y + thispos.Y, dobjpos.Z + thispos.Z);
             d.MassTranslate(ref objdmass, -objdmass.c.X, -objdmass.c.Y, -objdmass.c.Z); // ode wants inertia at center of body
             d.BodySetMass(Body, ref objdmass);
-            _mass = objdmass.mass;
+            m_mass = objdmass.mass;
         }
 
         private void FixInertia(Vector3 NewPos)
@@ -2145,7 +2294,7 @@ namespace OpenSim.Region.PhysicsModule.ubOde
             d.BodySetPosition(Body, dobjpos.X + thispos.X, dobjpos.Y + thispos.Y, dobjpos.Z + thispos.Z);
             d.MassTranslate(ref objdmass, -objdmass.c.X, -objdmass.c.Y, -objdmass.c.Z); // ode wants inertia at center of body
             d.BodySetMass(Body, ref objdmass);
-            _mass = objdmass.mass;
+            m_mass = objdmass.mass;
         }
 
         private void FixInertia(Quaternion newrot)
@@ -2211,7 +2360,7 @@ namespace OpenSim.Region.PhysicsModule.ubOde
             d.BodySetPosition(Body, dobjpos.X + thispos.X, dobjpos.Y + thispos.Y, dobjpos.Z + thispos.Z);
             d.MassTranslate(ref objdmass, -objdmass.c.X, -objdmass.c.Y, -objdmass.c.Z); // ode wants inertia at center of body
             d.BodySetMass(Body, ref objdmass);
-            _mass = objdmass.mass;
+            m_mass = objdmass.mass;
         }
 
 
@@ -2226,7 +2375,7 @@ namespace OpenSim.Region.PhysicsModule.ubOde
             if (primMass > _parent_scene.maximumMassObject)
                 primMass = _parent_scene.maximumMassObject;
 
-            _mass = primMass; // just in case
+            m_mass = primMass; // just in case
 
             d.MassSetBoxTotal(out primdMass, primMass, 2.0f * m_OBB.X, 2.0f * m_OBB.Y, 2.0f * m_OBB.Z);
 
@@ -3306,6 +3455,15 @@ namespace OpenSim.Region.PhysicsModule.ubOde
             m_useHoverPID = active;
         }
 
+        private void changeInertia(PhysicsInertiaData inertia)
+        {
+            m_InertiaOverride = inertia;
+
+            if (Body != IntPtr.Zero)
+                DestroyBody();
+            MakeBody();
+        }
+
         #endregion
 
         public void Move()
@@ -3346,7 +3504,7 @@ namespace OpenSim.Region.PhysicsModule.ubOde
                 float fy = 0;
                 float fz = 0;
 
-                float m_mass = _mass;
+                float mass = m_mass;
 
                 if (m_usePID && m_PIDTau > 0)
                 {
@@ -3453,9 +3611,9 @@ namespace OpenSim.Region.PhysicsModule.ubOde
                     fz = _parent_scene.gravityz * b;
                 }
 
-                fx *= m_mass;
-                fy *= m_mass;
-                fz *= m_mass;
+                fx *= mass;
+                fy *= mass;
+                fz *= mass;
 
                 // constant force
                 fx += m_force.X;
@@ -3941,6 +4099,10 @@ namespace OpenSim.Region.PhysicsModule.ubOde
                     changePIDHoverActive((bool)arg);
                     break;
 
+                case changes.SetInertia:
+                    changeInertia((PhysicsInertiaData) arg);
+                    break;
+
                 case changes.Null:
                     donullchange();
                     break;
@@ -3957,7 +4119,6 @@ namespace OpenSim.Region.PhysicsModule.ubOde
             _parent_scene.AddChange((PhysicsActor) this, what, arg);
         }
 
-
         private struct strVehicleBoolParam
         {
             public int param;
diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs
index 4c3f7ee..6c094ee 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.cs
@@ -4404,5 +4404,218 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
             m_host.ScriptSetVolumeDetect(detect != 0);
         }
 
+        /// <summary>
+        /// Get inertial data
+        /// </summary>
+        /// <remarks>
+        /// </remarks>
+        /// <returns>
+        /// a LSL list with contents:
+        ///     LSL_Float mass,  the total mass of a linkset
+        ///     LSL_Vector CenterOfMass, center mass relative to root prim
+        ///     LSL_Vector Inertia, elements of diagonal of inertia Ixx,Iyy,Izz divided by total mass
+        ///     LSL_Vector aux, elements of upper triagle of inertia Ixy (= Iyx), Ixz (= Izx), Iyz(= Izy) divided by total mass
+        /// </returns> 
+        public LSL_List osGetInertiaData()
+        {
+            LSL_List result = new LSL_List();
+            float TotalMass;
+            Vector3 CenterOfMass;
+            Vector3 Inertia;
+            Vector4 aux;
+
+            SceneObjectGroup sog = m_host.ParentGroup;
+            if(sog== null || sog.IsDeleted)
+                return result;          
+            
+            sog.GetInertiaData(out TotalMass, out CenterOfMass, out Inertia, out aux );
+            if(TotalMass > 0)
+            {
+                float t = 1.0f/TotalMass;
+                Inertia.X *= t;
+                Inertia.Y *= t;
+                Inertia.Z *= t;
+
+                aux.X *= t;
+                aux.Y *= t;
+                aux.Z *= t;
+            }
+
+            result.Add(new LSL_Float(TotalMass));
+            result.Add(new LSL_Vector(CenterOfMass.X, CenterOfMass.Y, CenterOfMass.Z));
+            result.Add(new LSL_Vector(Inertia.X, Inertia.Y, Inertia.Z));
+            result.Add(new LSL_Vector(aux.X, aux.Y, aux.Z));
+            return result;
+        }
+
+        /// <summary>
+        /// set inertial data
+        /// replaces the automatic calculation of mass, center of mass and inertia
+        /// 
+        /// </summary>
+        /// <param name="Mass">total mass of linkset</param>
+        /// <param name="centerOfMass">location of center of mass relative to root prim in local coords</param>
+        /// <param name="principalInertiaScaled">moment of inertia relative to principal axis and center of mass,Ixx, Iyy, Izz divided by mass</param>
+        /// <param name="lslrot">rotation of the inertia, relative to local axis</param>
+        /// <remarks>
+        /// the inertia argument is is inertia divided by mass, so corresponds only to the geometric distribution of mass and both can be changed independently.
+        /// </remarks>
+
+        public void osSetInertia(LSL_Float mass, LSL_Vector centerOfMass, LSL_Vector principalInertiaScaled,  LSL_Rotation lslrot)
+        {
+            SceneObjectGroup sog = m_host.ParentGroup;
+            if(sog== null || sog.IsDeleted)
+                return;
+
+            if(mass < 0 || principalInertiaScaled.x < 0 || principalInertiaScaled.y < 0 || principalInertiaScaled.z < 0)
+                return;
+
+            // need more checks
+
+            Vector3 CenterOfMass = new Vector3((float)centerOfMass.x,(float)centerOfMass.y,(float)centerOfMass.z);
+            Vector3 Inertia;          
+            float m = (float)mass;
+
+            Inertia.X = m * (float)principalInertiaScaled.x;
+            Inertia.Y = m * (float)principalInertiaScaled.y;
+            Inertia.Z = m * (float)principalInertiaScaled.z;
+
+            Vector4 rot = new Vector4((float)lslrot.x, (float)lslrot.y, (float)lslrot.y, (float)lslrot.s);
+            rot.Normalize();
+
+            sog.SetInertiaData(m, CenterOfMass, Inertia, rot );
+        }
+
+        /// <summary>
+        /// set inertial data as a sphere
+        /// replaces the automatic calculation of mass, center of mass and inertia
+        /// 
+        /// </summary>
+        /// <param name="Mass">total mass of linkset</param>
+        /// <param name="boxsize">size of the Box</param>
+        /// <param name="centerOfMass">location of center of mass relative to root prim in local coords</param>
+        /// <param name="lslrot">rotation of the box, and so inertia, relative to local axis</param>
+        /// <remarks>
+        /// </remarks>
+        public void osSetInertiaAsBox(LSL_Float mass, LSL_Vector boxSize, LSL_Vector centerOfMass, LSL_Rotation lslrot)
+        {
+            SceneObjectGroup sog = m_host.ParentGroup;
+            if(sog== null || sog.IsDeleted)
+                return;
+
+            if(mass < 0)
+                return;
+
+            // need more checks
+
+            Vector3 CenterOfMass = new Vector3((float)centerOfMass.x,(float)centerOfMass.y,(float)centerOfMass.z);
+            Vector3 Inertia;          
+            float lx = (float)boxSize.x;
+            float ly = (float)boxSize.y;
+            float lz = (float)boxSize.z;
+            float m = (float)mass;
+            float t = m / 12.0f;
+
+            Inertia.X = t * (ly*ly + lz*lz);
+            Inertia.Y = t * (lx*lx + lz*lz);
+            Inertia.Z = t * (lx*lx + ly*ly);
+
+            Vector4 rot = new Vector4((float)lslrot.x, (float)lslrot.y, (float)lslrot.z, (float)lslrot.s);
+            rot.Normalize();
+
+            sog.SetInertiaData(m, CenterOfMass, Inertia, rot );
+        }
+
+        /// <summary>
+        /// set inertial data as a sphere
+        /// replaces the automatic calculation of mass, center of mass and inertia
+        /// 
+        /// </summary>
+        /// <param name="Mass">total mass of linkset</param>
+        /// <param name="radius">radius of the sphere</param>
+        /// <param name="centerOfMass">location of center of mass relative to root prim in local coords</param>
+        /// <remarks>
+        /// </remarks>
+        public void osSetInertiaAsSphere(LSL_Float mass,  LSL_Float radius, LSL_Vector centerOfMass)
+        {
+            SceneObjectGroup sog = m_host.ParentGroup;
+            if(sog== null || sog.IsDeleted)
+                return;
+
+            if(mass < 0)
+                return;
+
+            // need more checks
+            
+            Vector3 CenterOfMass = new Vector3((float)centerOfMass.x,(float)centerOfMass.y,(float)centerOfMass.z);
+            Vector3 Inertia;          
+            float r = (float)radius;
+            float m = (float)mass;
+            float t = 0.4f * m * r * r;
+
+            Inertia.X = t;
+            Inertia.Y = t;
+            Inertia.Z = t;
+
+            sog.SetInertiaData(m, CenterOfMass, Inertia, new Vector4(0f, 0f, 0f,1.0f));
+        }
+
+        /// <summary>
+        /// set inertial data as a cylinder
+        /// replaces the automatic calculation of mass, center of mass and inertia
+        /// 
+        /// </summary>
+        /// <param name="Mass">total mass of linkset</param>
+        /// <param name="radius">radius of the cylinder</param>
+        /// <param name="lenght">lenght of the cylinder</param>
+        /// <param name="centerOfMass">location of center of mass relative to root prim in local coords</param>
+        /// <param name="lslrot">rotation of the cylinder, and so inertia, relative to local axis</param>
+        /// <remarks>
+        /// cylinder axis aligned with Z axis. For other orientations provide the rotation.
+        /// </remarks>
+        public void osSetInertiaAsCylinder(LSL_Float mass,  LSL_Float radius, LSL_Float lenght, LSL_Vector centerOfMass, LSL_Rotation lslrot)
+        {
+            SceneObjectGroup sog = m_host.ParentGroup;
+            if(sog== null || sog.IsDeleted)
+                return;
+
+            if(mass < 0)
+                return;
+
+            // need more checks
+            
+            Vector3 CenterOfMass = new Vector3((float)centerOfMass.x,(float)centerOfMass.y,(float)centerOfMass.z);
+            Vector3 Inertia;          
+            float m = (float)mass;
+            float r = (float)radius;
+            r *= r;
+            Inertia.Z = 0.5f * m * r;
+            float t = (float)lenght;
+            t *= t;
+            t += 3.0f * r;
+            t *= 8.333333e-2f * m;
+
+            Inertia.X = t;
+            Inertia.Y = t;
+
+            Vector4 rot = new Vector4((float)lslrot.x, (float)lslrot.y, (float)lslrot.z, (float)lslrot.s);
+            rot.Normalize();
+
+            sog.SetInertiaData(m, CenterOfMass, Inertia, rot);
+        }
+
+        /// <summary>
+        /// removes inertial data manual override
+        /// default automatic calculation is used again
+        /// 
+        /// </summary>
+        public void osClearInertia()
+        {
+            SceneObjectGroup sog = m_host.ParentGroup;
+            if(sog== null || sog.IsDeleted)
+                return;
+
+            sog.SetInertiaData(-1, Vector3.Zero, Vector3.Zero, Vector4.Zero );
+        }
     }
 }
diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Interface/IOSSL_Api.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Interface/IOSSL_Api.cs
index bee060a..f76ff7f 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Interface/IOSSL_Api.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Interface/IOSSL_Api.cs
@@ -38,6 +38,7 @@ using LSL_Integer = OpenSim.Region.ScriptEngine.Shared.LSL_Types.LSLInteger;
 using LSL_Float = OpenSim.Region.ScriptEngine.Shared.LSL_Types.LSLFloat;
 using LSL_Key = OpenSim.Region.ScriptEngine.Shared.LSL_Types.LSLString;
 
+
 namespace OpenSim.Region.ScriptEngine.Shared.Api.Interfaces
 {
     /// <summary>
@@ -486,6 +487,13 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api.Interfaces
         LSL_String osRequestURL(LSL_List options);
         LSL_String osRequestSecureURL(LSL_List options);
         void osCollisionSound(string impact_sound, double impact_volume);
+
         void osVolumeDetect(int detect);
+
+        LSL_List osGetInertiaData();
+        void osClearInertia();
+        void osSetInertiaAsBox(LSL_Float mass, vector boxSize, vector centerOfMass, rotation rot);
+        void osSetInertiaAsSphere(LSL_Float mass,  LSL_Float radius, vector centerOfMass);
+        void osSetInertiaAsCylinder(LSL_Float mass,  LSL_Float radius, LSL_Float lenght, vector centerOfMass,rotation lslrot);
     }
 }
diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/OSSL_Stub.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/OSSL_Stub.cs
index 6164734..09337e5 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/OSSL_Stub.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/OSSL_Stub.cs
@@ -1114,5 +1114,31 @@ namespace OpenSim.Region.ScriptEngine.Shared.ScriptBase
         {
             m_OSSL_Functions.osVolumeDetect(detect);
         }
+
+        public LSL_List osGetInertiaData()
+        {
+            return m_OSSL_Functions.osGetInertiaData();
+        }
+
+        public void osSetInertiaAsBox(LSL_Float mass, vector boxSize, vector centerOfMass, rotation rot)
+        {
+            m_OSSL_Functions.osSetInertiaAsBox(mass, boxSize, centerOfMass, rot);
+        }
+
+        public void osSetInertiaAsSphere(LSL_Float mass,  LSL_Float radius, vector centerOfMass)
+        {
+            m_OSSL_Functions.osSetInertiaAsSphere(mass, radius, centerOfMass);
+        }
+
+        public void osSetInertiaAsCylinder(LSL_Float mass,  LSL_Float radius, LSL_Float lenght, vector centerOfMass,rotation lslrot)
+        {
+            m_OSSL_Functions.osSetInertiaAsCylinder( mass, radius, lenght, centerOfMass, lslrot);
+        }
+
+        public void osClearInertia()
+        {
+            m_OSSL_Functions.osClearInertia();
+        }
+
     }
 }