C# HkContactPointEvent类代码示例

 public MyGridContactInfo(ref HkContactPointEvent evnt, MyCubeGrid grid)
 {
     Event = evnt;
     ContactPosition = grid.Physics.ClusterToWorld(evnt.ContactPoint.Position); 
     m_currentEntity = grid;
     m_collidingEntity = Event.GetOtherEntity(grid) as MyEntity;
     m_currentBlock = null;
     m_otherBlock = null;
     ImpulseMultiplier = 1;
 }

        void RigidBody_ContactPointCallback_Destruction(ref HkContactPointEvent value)
        {
            ProfilerShort.Begin("Grid Contact counter");
            ProfilerShort.End();
            MyGridContactInfo info = new MyGridContactInfo(ref value, m_grid);

            if (info.IsKnown)
                return;

            var myEntity = info.CurrentEntity;//value.Base.BodyA.GetEntity() == m_grid.Components ? value.Base.BodyA.GetEntity() : value.Base.BodyB.GetEntity();
            if (myEntity == null || myEntity.Physics == null || myEntity.Physics.RigidBody == null)
            {
                return;
            }
            var myBody = myEntity.Physics.RigidBody;

            // CH: DEBUG
            var physicsBody1 = value.GetPhysicsBody(0);
            var physicsBody2 = value.GetPhysicsBody(1);
            if (physicsBody1 == null || physicsBody2 == null)
                return;

            var entity1 = physicsBody1.Entity;
            var entity2 = physicsBody2.Entity;
            if (entity1 == null || entity2 == null || entity1.Physics == null || entity2.Physics == null)
                return;

            if (entity1 is MyFracturedPiece && entity2 is MyFracturedPiece)
                return;

            var rigidBody1 = value.Base.BodyA;
            var rigidBody2 = value.Base.BodyB;

            info.HandleEvents();
            if (rigidBody1.HasProperty(HkCharacterRigidBody.MANIPULATED_OBJECT) || rigidBody2.HasProperty(HkCharacterRigidBody.MANIPULATED_OBJECT))
                return;

            if (info.CollidingEntity is Sandbox.Game.Entities.Character.MyCharacter || info.CollidingEntity == null || info.CollidingEntity.MarkedForClose)
                return;

            var grid1 = entity1 as MyCubeGrid;
            var grid2 = entity2 as MyCubeGrid;

            // CH: TODO: This is a hack Instead, the IMyDestroyableObject should be used and the subpart DoDamage code could delegate it to the grid
            // The thing is, this approach would probably need a rewrite of this whole method...
            if (grid2 == null && entity2 is MyEntitySubpart)
            {
                while (entity2 != null && !(entity2 is MyCubeGrid))
                {
                    entity2 = entity2.Parent;
                }

                if (entity2 != null)
                {
                    physicsBody2 = entity2.Physics as MyPhysicsBody;
                    rigidBody2 = physicsBody2.RigidBody;
                    grid2 = entity2 as MyCubeGrid;
                }
            }

            if (grid1 != null && grid2 != null && (MyCubeGridGroups.Static.Physical.GetGroup(grid1) == MyCubeGridGroups.Static.Physical.GetGroup(grid2)))
                return;

            ProfilerShort.Begin("Grid contact point callback");

            {
                var vel = Math.Abs(value.SeparatingVelocity);
                bool enoughSpeed = vel > 3;
                //float dot = Vector3.Dot(Vector3.Normalize(LinearVelocity), Vector3.Normalize(info.CollidingEntity.Physics.LinearVelocity));


                Vector3 velocity1 = rigidBody1.GetVelocityAtPoint(info.Event.ContactPoint.Position);
                Vector3 velocity2 = rigidBody2.GetVelocityAtPoint(info.Event.ContactPoint.Position);

                float speed1 = velocity1.Length();
                float speed2 = velocity2.Length();

                Vector3 dir1 = speed1 > 0 ? Vector3.Normalize(velocity1) : Vector3.Zero;
                Vector3 dir2 = speed2 > 0 ? Vector3.Normalize(velocity2) : Vector3.Zero;

                float mass1 = MyDestructionHelper.MassFromHavok(rigidBody1.Mass);
                float mass2 = MyDestructionHelper.MassFromHavok(rigidBody2.Mass);

                float impact1 = speed1 * mass1;
                float impact2 = speed2 * mass2;

                float dot1withNormal = speed1 > 0 ? Vector3.Dot(dir1, value.ContactPoint.Normal) : 0;
                float dot2withNormal = speed2 > 0 ? Vector3.Dot(dir2, value.ContactPoint.Normal) : 0;

                speed1 *= Math.Abs(dot1withNormal);
                speed2 *= Math.Abs(dot2withNormal);

                bool is1Static = mass1 == 0;
                bool is2Static = mass2 == 0;

                bool is1Small = entity1 is MyFracturedPiece || (grid1 != null && grid1.GridSizeEnum == MyCubeSize.Small);
                bool is2Small = entity2 is MyFracturedPiece || (grid2 != null && grid2.GridSizeEnum == MyCubeSize.Small);


                float dot = Vector3.Dot(dir1, dir2);
//.........这里部分代码省略.........

 protected Sandbox.ModAPI.IMyEntity GetOtherEntity(ref HkContactPointEvent value)
 {
     if (value.Base.BodyA.GetEntity() == this)
         return value.Base.BodyB.GetEntity();
     else
         return value.Base.BodyA.GetEntity();
 }

        public void PlayContactSound(HkContactPointEvent value, float volume = 0)
        {
            ProfilerShort.Begin("PlayContactSound");
            var bodyA = value.Base.BodyA.GetBody();
            var bodyB = value.Base.BodyB.GetBody();
            if (bodyA == null || bodyB == null)
            {
                ProfilerShort.End();
                return;
            }
            ProfilerShort.BeginNextBlock("GetMaterial");
            var worldPos = ClusterToWorld(value.ContactPoint.Position);
            var materialA = bodyA.GetMaterialAt(worldPos + value.ContactPoint.Normal * 0.1f);
            var materialB = bodyB.GetMaterialAt(worldPos - value.ContactPoint.Normal * 0.1f);
            /*if (materialA == m_character || materialB == m_character)
            {
                ProfilerShort.End();
                return;
            }*/
            ProfilerShort.Begin("Lambdas");
            var colision = value.Base;
            Func<bool> canHear = () =>
            {
                if (MySession.Static.ControlledEntity != null)
                {
                    var entity = MySession.Static.ControlledEntity.Entity.GetTopMostParent();
                    return (entity == value.GetPhysicsBody(0).Entity || entity == value.GetPhysicsBody(1).Entity);
                }
                return false;
            };

            Func<bool> shouldPlay2D = () => MySession.Static.ControlledEntity != null && MySession.Static.ControlledEntity.Entity is MyCharacter && (
                            MySession.Static.ControlledEntity.Entity.Components == value.GetPhysicsBody(0).Entity || MySession.Static.ControlledEntity.Entity.Components == value.GetPhysicsBody(1).Entity);

            ProfilerShort.BeginNextBlock("Volume");
            if (volume == 0)
            {
                //var vel = value.Base.BodyA.LinearVelocity - value.Base.BodyB.LinearVelocity;
                //if (System.Math.Abs(Vector3.Normalize(vel).Dot(value.ContactPoint.Normal)) < 0.7f)\
                //var val = System.Math.Abs(Vector3.Normalize(vel).Dot(value.ContactPoint.Normal)) * vel.Length();
                //var mass = value.Base.BodyA.Mass;
                //var massB = value.Base.BodyB.Mass;
                //mass = mass == 0 ? massB : massB == 0 ? mass : mass < massB ? mass : massB; // select smaller mass > 0
                //mass /= 40; //reference mass
                //val *= mass;
                if (Math.Abs(value.SeparatingVelocity) < 10f)
                    volume = 0.5f + Math.Abs(value.SeparatingVelocity) / 20f;
                else
                    volume = 1f;
            }

            ProfilerShort.BeginNextBlock("PlaySound");
            bool firstOneIsLighter = bodyB.Entity is MyVoxelBase || bodyB.Entity.Physics == null;
            if (firstOneIsLighter == false && bodyA.Entity.Physics != null && bodyA.Entity.Physics.IsStatic == false && (bodyB.Entity.Physics.IsStatic || bodyA.Entity.Physics.Mass < bodyB.Entity.Physics.Mass))
                firstOneIsLighter = true;
            if (firstOneIsLighter)
                MyAudioComponent.PlayContactSound(bodyA.Entity.EntityId, m_startCue, worldPos, materialA, materialB, volume, canHear, surfaceEntity: (MyEntity)bodyB.Entity, separatingVelocity: Math.Abs(value.SeparatingVelocity));
            else
                MyAudioComponent.PlayContactSound(bodyB.Entity.EntityId, m_startCue, worldPos, materialB, materialA, volume, canHear, surfaceEntity: (MyEntity)bodyA.Entity, separatingVelocity: Math.Abs(value.SeparatingVelocity));
            ProfilerShort.End();
            ProfilerShort.End();
        }

        //Vector3 GetVelocityAtPoint(Vector3D worldPos)
        //{
        //    return LinearVelocity + AngularVelocity.Cross(worldPos - CenterOfMassWorld);
        //}

        void OnContactPointCallback(ref HkContactPointEvent e)
        {
            ProfilerShort.Begin("PhysicsBody.OnContacPointCallback");
            if (ContactPointCallback != null)
            {
                var offset = MyPhysics.Clusters.GetObjectOffset(ClusterObjectID);

                MyPhysics.MyContactPointEvent ce = new MyPhysics.MyContactPointEvent()
                {
                    ContactPointEvent = e,
                    Position = e.ContactPoint.Position + offset
                };

                ContactPointCallback(ref ce);
            }
            ProfilerShort.End();
        }

 //isnt used
 void RigidBody_ContactPointCallback(ref HkContactPointEvent value)
 {
     if (!Sync.IsServer)
         return;
     var entity = value.GetOtherEntity(this);
     if (entity is MyFloatingObject)
     {
         m_entitiesToTake.Add(entity as MyFloatingObject);
         NeedsUpdate |= MyEntityUpdateEnum.BEFORE_NEXT_FRAME;
     }
 }

        private DamageImpactEnum GetDamageFromHit(HkRigidBody collidingBody, MyEntity collidingEntity, ref HkContactPointEvent value)
        {
            if (collidingBody.LinearVelocity.Length() < MyPerGameSettings.CharacterDamageHitObjectMinVelocity) return DamageImpactEnum.NoDamage;

            if (collidingEntity == ManipulatedEntity) return DamageImpactEnum.NoDamage;

            if (collidingBody.HasProperty(HkCharacterRigidBody.MANIPULATED_OBJECT)) return DamageImpactEnum.NoDamage;

            var mass = (MyPerGameSettings.Destruction ? MyDestructionHelper.MassFromHavok(collidingBody.Mass) : collidingBody.Mass);
            if (mass < MyPerGameSettings.CharacterDamageHitObjectMinMass) return DamageImpactEnum.NoDamage;

            // Get the objects energies to calculate the damage - must be higher above treshold
            float objectEnergy = Math.Abs(value.SeparatingVelocity) * mass;

            if (objectEnergy > MyPerGameSettings.CharacterDamageHitObjectDeadlyEnergy) return DamageImpactEnum.DeadlyDamage;
            if (objectEnergy > MyPerGameSettings.CharacterDamageHitObjectCriticalEnergy) return DamageImpactEnum.CriticalDamage;
            if (objectEnergy > MyPerGameSettings.CharacterDamageHitObjectMediumEnergy) return DamageImpactEnum.MediumDamage;
            if (objectEnergy > MyPerGameSettings.CharacterDamageHitObjectSmallEnergy) return DamageImpactEnum.SmallDamage;

            return DamageImpactEnum.NoDamage;
        }

        private void CalculateDamageAfterCollision(ref HkContactPointEvent value)
        {
            // Are bodies moving one to another? if not we do not apply damage
            if (value.SeparatingVelocity < 0)
            {
                if (!Sync.IsServer) return;

                DamageImpactEnum damageImpact = DamageImpactEnum.NoDamage;

                // Get the colliding object and skip collisions between characters
                HkRigidBody collidingBody;
                int collidingBodyIdx = 0;
                if (value.Base.BodyA == Physics.CharacterProxy.GetHitRigidBody())
                {
                    collidingBody = value.Base.BodyB;
                    collidingBodyIdx = 1;
                }
                else
                    collidingBody = value.Base.BodyA;
                MyEntity collidingEntity = value.GetPhysicsBody(collidingBodyIdx).Entity as MyEntity;
                if (collidingEntity == null || collidingEntity is MyCharacter) return;

                if (MyDebugDrawSettings.ENABLE_DEBUG_DRAW && MyDebugDrawSettings.DEBUG_DRAW_SHOW_DAMAGE)
                {
                    MatrixD worldMatrix = collidingEntity.Physics.GetWorldMatrix();
                    int index = 0;
                    MyPhysicsDebugDraw.DrawCollisionShape(collidingBody.GetShape(), worldMatrix, 1, ref index, "hit");
                }

                damageImpact = GetDamageFromFall(collidingBody, collidingEntity, ref value);

                if (damageImpact != DamageImpactEnum.NoDamage) ApplyDamage(damageImpact, MyDamageType.Fall);

                damageImpact = GetDamageFromHit(collidingBody, collidingEntity, ref value);

                if (MyDebugDrawSettings.ENABLE_DEBUG_DRAW && MyDebugDrawSettings.DEBUG_DRAW_SHOW_DAMAGE)
                {
                    if (damageImpact != DamageImpactEnum.NoDamage)
                    {
                        MatrixD worldMatrix = collidingEntity.Physics.GetWorldMatrix();
                        VRageRender.MyRenderProxy.DebugDrawSphere(worldMatrix.Translation, collidingBody.Mass, Color.Red, 1, false);
                        VRageRender.MyRenderProxy.DebugDrawText3D(worldMatrix.Translation, "MASS: " + collidingBody.Mass, Color.Red, 1, false);
                    }
                }

                if (damageImpact != DamageImpactEnum.NoDamage) ApplyDamage(damageImpact, MyDamageType.Environment);

                damageImpact = GetDamageFromSqueeze(collidingBody, collidingEntity, ref value);

                if (damageImpact != DamageImpactEnum.NoDamage) ApplyDamage(damageImpact, MyDamageType.Squeez);

            }
        }

	    internal void TrySpawnWalkingParticles(ref HkContactPointEvent value)
	    {
		    if (!MyFakes.ENABLE_WALKING_PARTICLES)
			    return;
            
		    var oldCheckTime = m_lastWalkParticleCheckTime;
		    m_lastWalkParticleCheckTime = MySandboxGame.TotalGamePlayTimeInMilliseconds;
		    m_walkParticleSpawnCounterMs -= m_lastWalkParticleCheckTime - oldCheckTime;
		    if (m_walkParticleSpawnCounterMs > 0)
			    return;

			var naturalGravityMultiplier = MyGravityProviderSystem.CalculateHighestNaturalGravityMultiplierInPoint(Entity.PositionComp.WorldMatrix.Translation);
		    if (naturalGravityMultiplier <= 0f)
		    {
			    m_walkParticleSpawnCounterMs = m_walkParticleGravityDelay;
			    return;
		    }

		    var character = Entity as MyCharacter;
		    if (character.JetpackComp != null && character.JetpackComp.Running)
		    {
			    m_walkParticleSpawnCounterMs = m_walkParticleJetpackOffDelay;
			    return;
		    }

		    var currentMovementState = character.GetCurrentMovementState();
		    if (currentMovementState.GetDirection() == MyCharacterMovement.NoDirection || currentMovementState == MyCharacterMovementEnum.Falling)
		    {
			    m_walkParticleSpawnCounterMs = m_walkParticleDefaultDelay;
			    return;
		    }

		    var otherPhysicsBody = value.GetOtherEntity(character).Physics as MyVoxelPhysicsBody;//value.Base.BodyA.UserObject == character.Physics ? value.Base.BodyB.UserObject : value.Base.BodyA.UserObject)) as MyVoxelPhysicsBody;
		    if (otherPhysicsBody == null)
			    return;
	       
			MyStringId movementType;

		    const int walkParticleWalkDelay = 500;
			const int walkParticleRunDelay = 275;
			const int walkParticleSprintDelay = 250;
		    switch (currentMovementState.GetSpeed())
		    {
			    case MyCharacterMovement.NormalSpeed:
				    movementType = MyMaterialPropertiesHelper.CollisionType.Walk;
				    m_walkParticleSpawnCounterMs = walkParticleWalkDelay;
				    break;
				case MyCharacterMovement.Fast:
					movementType = MyMaterialPropertiesHelper.CollisionType.Run;
				    m_walkParticleSpawnCounterMs = walkParticleRunDelay;
				    break;
				case MyCharacterMovement.VeryFast:
					movementType = MyMaterialPropertiesHelper.CollisionType.Sprint;
				    m_walkParticleSpawnCounterMs = walkParticleSprintDelay;
				    break;
				default:
				    movementType = MyMaterialPropertiesHelper.CollisionType.Walk;
				    m_walkParticleSpawnCounterMs = m_walkParticleDefaultDelay;
				    break;

		    }

            var spawnPosition = otherPhysicsBody.ClusterToWorld(value.ContactPoint.Position);

            MyVoxelMaterialDefinition voxelMaterialDefinition = otherPhysicsBody.m_voxelMap.GetMaterialAt(ref spawnPosition);
		    if (voxelMaterialDefinition == null)
			    return;

		    MyMaterialPropertiesHelper.Static.TryCreateCollisionEffect(
				movementType,
				spawnPosition,
				value.ContactPoint.Normal,
				m_characterMaterial,
				MyStringHash.GetOrCompute(voxelMaterialDefinition.MaterialTypeName));
	    }

        void RigidBody_ContactPointCallback(ref HkContactPointEvent value)
        {
            ProfilerShort.Begin("Grid Contact counter");
            ProfilerShort.End();

            var otherEntity = value.GetOtherEntity(m_grid);
            var otherPhysicsBody = value.GetPhysicsBody(0);
            var thisEntity = m_grid;
            if (otherEntity == null || thisEntity == null)
                return;

            //DA used to stop appliyng force when there is planet/ship collisions to  increase performance after ship crashes on planet
            if ((Math.Abs(value.SeparatingVelocity) < 0.3f) && (otherEntity is MyTrees || otherEntity is MyVoxelPhysics))
            {
                return;
            }

            MyGridContactInfo info = new MyGridContactInfo(ref value, m_grid);

            var myBody = RigidBody;// value.Base.BodyA.GetEntity() == m_grid.Components ? value.Base.BodyA : value.Base.BodyB;

            if (info.CollidingEntity is Sandbox.Game.Entities.Character.MyCharacter || info.CollidingEntity.MarkedForClose)
                return;

            if (MyFakes.LANDING_GEAR_IGNORE_DAMAGE_CONTACTS && MyCubeGridGroups.Static.NoContactDamage.HasSameGroupAndIsGrid(otherEntity, thisEntity))
                return;

            ProfilerShort.Begin("Grid contact point callback");
            bool hitVoxel = info.CollidingEntity is MyVoxelMap || info.CollidingEntity is MyVoxelPhysics;

            if(hitVoxel && m_grid.Render != null) {
                m_grid.Render.ResetLastVoxelContactTimer();
            }

            bool doSparks = MyPerGameSettings.EnableCollisionSparksEffect && (info.CollidingEntity is MyCubeGrid || hitVoxel);

            // According to Petr, WasUsed does not work everytime
            //if (value.ContactProperties.WasUsed)
            {
                // Handle callbacks here
                info.HandleEvents();
            }

            if(MyDebugDrawSettings.DEBUG_DRAW_FRICTION)
            {
                var pos = ClusterToWorld(value.ContactPoint.Position);
                var vel = -GetVelocityAtPoint(pos);
                vel *= 0.1f;
                var fn = Math.Abs(Gravity.Dot(value.ContactPoint.Normal) * value.ContactProperties.Friction);
                if (vel.Length() > 0.5f)
                {
                    vel.Normalize();
                    MyRenderProxy.DebugDrawArrow3D(pos, pos + fn * vel, Color.Gray, Color.Gray, false);
                }
            }

            if (doSparks && Math.Abs(value.SeparatingVelocity) > 2.0f && value.ContactProperties.WasUsed && !m_lastContacts.ContainsKey(value.ContactPointId) && info.EnableParticles)
            {
                ProfilerShort.Begin("AddCollisionEffect");
                m_lastContacts[value.ContactPointId] = MySandboxGame.TotalGamePlayTimeInMilliseconds;
                AddCollisionEffect(info.ContactPosition, value.ContactPoint.Normal);
                ProfilerShort.End();
            }

            ProfilerShort.Begin("Dust");
            bool doDust = MyPerGameSettings.EnableCollisionSparksEffect && hitVoxel;
            float force = Math.Abs(value.SeparatingVelocity * (Mass / 100000));
            if (doDust && force > 0.25f && info.EnableParticles)
            {
                float scale = MathHelper.Clamp(force / 10.0f, 0.2f, 4.0f);
                AddDustEffect(info.ContactPosition, scale);
            }
            ProfilerShort.End();
            // Large dynamic ships colliding with floating objects
            // When low separating velocity or deformation performed, disable contact point
            // Floating object will still collide with kinematic part of ship and won't push it
            if (m_grid.GridSizeEnum == MyCubeSize.Large && !myBody.IsFixedOrKeyframed && info.CollidingEntity is MyFloatingObject && (Math.Abs(value.SeparatingVelocity) < 0.2f))
            {
                var prop = value.ContactProperties;
                prop.IsDisabled = true;
            }

            ProfilerShort.End();
        }

 public void RegisterObstacleContact(ref HkContactPointEvent e)
 {
     if (m_obstacleContact == false && m_fallSoundShouldPlay.Value == true && (DateTime.UtcNow - m_soundStart).TotalSeconds >= 1f)
     {
         m_obstacleContact = true;
     }
 }

        void RigidBody_ContactPointCallback(ref HkContactPointEvent value)
        {
            if (Physics.CharacterProxy == null)
                return;

            if (!MySession.Static.Ready)
                return;

            if (value.Base.BodyA == null || value.Base.BodyB == null)
                return;

            if (value.Base.BodyA.UserObject == null || value.Base.BodyB.UserObject == null)
                return;

            if (value.Base.BodyA.HasProperty(HkCharacterRigidBody.MANIPULATED_OBJECT) || value.Base.BodyB.HasProperty(HkCharacterRigidBody.MANIPULATED_OBJECT))
                return;
        }

 void RigidBody_ContactPointCallback(ref HkContactPointEvent value)
 {
     if (ContactPointCallback != null)
         ContactPointCallback(ref value);
 }

        public void PlayContactSound(HkContactPointEvent value, float volume = 0)
        {
            ProfilerShort.Begin("PlayContactSound");
            var bodyA = value.Base.BodyA.GetBody();
            var bodyB = value.Base.BodyB.GetBody();
            if (bodyA == null || bodyB == null)
            {
                ProfilerShort.End();
                return;
            }

            var colision = value.Base;
            Func<bool> canHear = () =>
            {
                if (MySession.ControlledEntity != null)
                {
                    var entity = MySession.ControlledEntity.Entity.GetTopMostParent();
                    return (entity == value.GetPhysicsBody(0).Entity || entity == value.GetPhysicsBody(1).Entity);
                }
                return false;
            };

            Func<bool> shouldPlay2D = () => MySession.ControlledEntity != null && MySession.ControlledEntity.Entity is MyCharacter && (
                            MySession.ControlledEntity.Entity.Components == value.GetPhysicsBody(0).Entity || MySession.ControlledEntity.Entity.Components == value.GetPhysicsBody(1).Entity);

            if (volume == 0)
            {
                var vel = value.Base.BodyA.LinearVelocity - value.Base.BodyB.LinearVelocity;
                //if (System.Math.Abs(Vector3.Normalize(vel).Dot(value.ContactPoint.Normal)) < 0.7f)\
                var val = System.Math.Abs(Vector3.Normalize(vel).Dot(value.ContactPoint.Normal)) * vel.Length();
                //var mass = value.Base.BodyA.Mass;
                //var massB = value.Base.BodyB.Mass;
                //mass = mass == 0 ? massB : massB == 0 ? mass : mass < massB ? mass : massB; // select smaller mass > 0
                //mass /= 40; //reference mass
                //val *= mass;
                if (val < 10)
                    volume = val / 10;
                else
                    volume = 1;
            }

            var worldPos = ClusterToWorld(value.ContactPoint.Position);
            var materialA = bodyA.GetMaterialAt(worldPos + value.ContactPoint.Normal * 0.1f);
            var materialB = bodyB.GetMaterialAt(worldPos - value.ContactPoint.Normal * 0.1f);


            MyAudioComponent.PlayContactSound(Entity.EntityId, worldPos, materialA, materialB, volume, canHear);

            ProfilerShort.End();
        }

 protected IMyEntity GetOtherEntity(ref HkContactPointEvent value)
 {
     if (value.Base.BodyA.GetEntity() == Entity)
         return value.Base.BodyB.GetEntity();
     else
         return value.Base.BodyA.GetEntity();
 }