dNewtonCollision* dNewtonContactMaterial::GetShape1 (const void* const contact)
{
	NewtonBody* const body = NewtonJointGetBody1 ((NewtonJoint*)m_materialHandle);
	NewtonMaterial* const material = NewtonContactGetMaterial (contact);
	NewtonCollision* const collision = NewtonMaterialGetBodyCollidingShape (material, body);
	return (dNewtonCollision*)NewtonCollisionGetUserData(collision);
}
static void UserContactRestitution (const NewtonJoint* contactJoint, dFloat timestep, int threadIndex)
{
	dFloat Ixx;
	dFloat Iyy;
	dFloat Izz;
	dFloat mass;
	NewtonBody* body;
	NewtonBody* body0;
	NewtonBody* body1;

	// call  the basic call back
	GenericContactProcess (contactJoint, timestep, threadIndex);

	body0 = NewtonJointGetBody0(contactJoint);
	body1 = NewtonJointGetBody1(contactJoint);

	body = body0;
	NewtonBodyGetMassMatrix (body, &mass, &Ixx, &Iyy, &Izz);
	if (mass == 0.0f) {
		body = body1;
	}

	NewtonCollision* const collision = NewtonBodyGetCollision(body);
	void* userData = NewtonCollisionGetUserData (collision);
	dFloat restitution = *((float*)&userData);
	for (void* contact = NewtonContactJointGetFirstContact (contactJoint); contact; contact = NewtonContactJointGetNextContact (contactJoint, contact)) {
		NewtonMaterial* const material = NewtonContactGetMaterial (contact);
		NewtonMaterialSetContactElasticity (material, restitution);
	}
}
Example #3
0
void GenericContactProcess (const NewtonJoint* contactJoint, dFloat timestep, int threadIndex)
{
	int isHightField;
	NewtonBody* body;
	NewtonCollision* collision;
	NewtonCollisionInfoRecord info;

	isHightField = 1;
	body = NewtonJointGetBody0 (contactJoint);
	collision = NewtonBodyGetCollision(body);
	NewtonCollisionGetInfo(collision, &info);
	if (info.m_collisionType != SERIALIZE_ID_HEIGHTFIELD) {
		body = NewtonJointGetBody1 (contactJoint);
		collision = NewtonBodyGetCollision(body);
		NewtonCollisionGetInfo(collision, &info);
		isHightField  = (info.m_collisionType == SERIALIZE_ID_HEIGHTFIELD); 
	}

	#define HOLE_IN_TERRAIN 10
	if (isHightField) {
		void* nextContact;
		for (void* contact = NewtonContactJointGetFirstContact (contactJoint); contact; contact = nextContact) {
			int faceID;
			NewtonMaterial* material;

			nextContact = NewtonContactJointGetNextContact (contactJoint, contact);

			material = NewtonContactGetMaterial (contact);
			faceID = NewtonMaterialGetContactFaceAttribute (material);
			if (faceID == HOLE_INTERRAIN) {
				NewtonContactJointRemoveContact (contactJoint, contact); 
			}
		}
	}
}
Example #4
0
void GetForceOnStaticBody (NewtonBody* body, NewtonBody* staticBody)
{
	for (NewtonJoint* joint = NewtonBodyGetFirstContactJoint (body); joint; joint = NewtonBodyGetNextContactJoint (body, joint)) {
		NewtonBody* body0;
		NewtonBody* body1;

		body0 = NewtonJointGetBody0(joint);
		body1 = NewtonJointGetBody1(joint);
		if ((body0 == staticBody) || (body1 == staticBody)) {

			for (void* contact = NewtonContactJointGetFirstContact (joint); contact; contact = NewtonContactJointGetNextContact (joint, contact)) {

				float forceMag;
				dVector point;
				dVector normal;	
				NewtonMaterial* material;

				material = NewtonContactGetMaterial (contact);
				
				NewtonMaterialGetContactForce (material, &forceMag);
				NewtonMaterialGetContactPositionAndNormal (material, &point.m_x, &normal.m_x);

				dVector force (normal.Scale (-forceMag));

				// do wherever you want withteh force
			}
		}
	}
}
static void UserContactFriction (const NewtonJoint* contactJoint, dFloat timestep, int threadIndex)
{
	dFloat Ixx;
	dFloat Iyy;
	dFloat Izz;
	dFloat mass;

	// call  the basic call back
	GenericContactProcess (contactJoint, timestep, threadIndex);

	const NewtonBody* const body0 = NewtonJointGetBody0(contactJoint);
	const NewtonBody* const body1 = NewtonJointGetBody1(contactJoint);
	const NewtonBody* body = body0;
	NewtonBodyGetMass (body, &mass, &Ixx, &Iyy, &Izz);
	if (mass == 0.0f) {
		body = body1;
	}

	//now core 300 can have per collision user data 		
	NewtonCollision* const collision = NewtonBodyGetCollision(body);
	void* userData = NewtonCollisionGetUserData (collision);
	dFloat frictionValue = *((dFloat*)&userData);
	for (void* contact = NewtonContactJointGetFirstContact (contactJoint); contact; contact = NewtonContactJointGetNextContact (contactJoint, contact)) {
		NewtonMaterial* const material = NewtonContactGetMaterial (contact);
		NewtonMaterialSetContactFrictionCoef (material, frictionValue + 0.1f, frictionValue, 0);
		NewtonMaterialSetContactFrictionCoef (material, frictionValue + 0.1f, frictionValue, 1);
	}
}
void CustomTriggerManager::UpdateTrigger (CustomTriggerController* const controller)
{
	NewtonBody* const triggerBody = controller->GetBody();
	dTree<NewtonBody*,NewtonBody*>& manifest = controller->m_manifest;

	for (NewtonJoint* joint = NewtonBodyGetFirstContactJoint (triggerBody); joint; joint = NewtonBodyGetNextContactJoint (triggerBody, joint)) {

		int isActive = NewtonJointIsActive (joint);
		NewtonBody* const body0 = NewtonJointGetBody0(joint);
		NewtonBody* const body1 = NewtonJointGetBody1(joint);
		NewtonBody* const passangerBody = (body0 != triggerBody) ? body0 : body1; 
		
		if (isActive) {
			dTree<NewtonBody*,NewtonBody*>::dTreeNode* const passengerNode = manifest.Find (passangerBody);
			if (passengerNode) {
				EventCallback (controller, m_inTrigger, passangerBody);

			} else {
				CustomScopeLock lock (&m_lock);
				manifest.Insert (passangerBody, passangerBody);
				EventCallback (controller, m_enterTrigger, passangerBody);
			} 
		} else {
			dTree<NewtonBody*,NewtonBody*>::dTreeNode* const passengerNode = manifest.Find (passangerBody);

			if (passengerNode) {
				EventCallback (controller, m_exitTrigger, passangerBody);

				CustomScopeLock lock (&m_lock);
				manifest.Remove (passengerNode);
			}
		}
	}
}
Example #7
0
static void PhysicsNewton_CollisionPuckSurfaceCB(const NewtonJoint *pContactJoint,dFloat fTimeStep,int ThreadIndex)
{
	dVector Position(0.0f);
	
	// Get pointer to body
	NewtonBody* body = NewtonJointGetBody0(pContactJoint);				
	dFloat mass, Ixx, Iyy, Izz;
	NewtonBodyGetMass(body, &mass, &Ixx, &Iyy, &Izz);
	if (mass == 0.0f)
	{
		body = NewtonJointGetBody1(pContactJoint);
	}	

	dVector tableDir(0.0f, 0.0f, 1.0f, 0.0f);
	// Test to see if it is the friction calculation that is causing the side force
	// With this the Puck must go straight because it will be frictionless, the net force should not change direction
	for (void* contact = NewtonContactJointGetFirstContact (pContactJoint); contact; contact = NewtonContactJointGetNextContact (pContactJoint, contact))
	{
		NewtonMaterial* const material = NewtonContactGetMaterial (contact);

		NewtonMaterialContactRotateTangentDirections(material, &tableDir[0]);

		// this the wrong way to make a friction less contact  
//		NewtonMaterialSetContactFrictionCoef (material, 0.0f, 0.0f, 0);
//		NewtonMaterialSetContactFrictionCoef (material, 0.0f, 0.0f, 1);

		//This is the correct way to make a friction less contact		
//		NewtonMaterialSetContactFrictionState (material, 0, 0);
//		NewtonMaterialSetContactFrictionState (material, 0, 1);
	}
}
Example #8
0
    void GenericContactProcessCompatible(const void* const newtonContactJoint, float64 timestep, int threadIndex)
    {
        con_assert(newtonContactJoint != nullptr, "zero pointer")

            NewtonBody* body0 = NewtonJointGetBody0(static_cast<const NewtonJoint*>(newtonContactJoint));
        NewtonBody* body1 = NewtonJointGetBody1(static_cast<const NewtonJoint*>(newtonContactJoint));

        con_assert(body0 != nullptr && body1 != nullptr, "zero pointers")

            if (body0 != nullptr && body1 != nullptr)
            {
                iPhysicsBody* physicsBody0 = static_cast<iPhysicsBody*>(NewtonBodyGetUserData(static_cast<const NewtonBody*>(body0)));
                iPhysicsBody* physicsBody1 = static_cast<iPhysicsBody*>(NewtonBodyGetUserData(static_cast<const NewtonBody*>(body1)));

                con_assert(physicsBody0 != nullptr && physicsBody1 != nullptr, "zero pointers");

                void* contact = NewtonContactJointGetFirstContact(static_cast<const NewtonJoint*>(newtonContactJoint));
                NewtonMaterial* materialCombo = NewtonContactGetMaterial(contact);
                iPhysicsMaterialCombo* physicsMaterialCombo = static_cast<iPhysicsMaterialCombo*>(NewtonMaterialGetMaterialPairUserData(materialCombo));

                if (physicsMaterialCombo != nullptr && physicsBody0 != nullptr && physicsBody1 != nullptr)
                {
                    physicsMaterialCombo->contact(physicsBody0, physicsBody1);
                }
            }
    }
Example #9
0
VALUE MSNewton::Bodies::get_force_in_between(VALUE self, VALUE v_body1, VALUE v_body2) {
	const NewtonBody* body1 = Util::value_to_body(v_body1);
	const NewtonBody* body2 = Util::value_to_body(v_body2);
	Util::validate_two_bodies(body1, body2);
	dVector net_force(0.0f, 0.0f, 0.0f);
	for (NewtonJoint* joint = NewtonBodyGetFirstContactJoint(body1); joint; joint = NewtonBodyGetNextContactJoint(body1, joint)) {
		if (NewtonJointGetBody0(joint) == body2 || NewtonJointGetBody1(joint) == body2) {
			for (void* contact = NewtonContactJointGetFirstContact(joint); contact; contact = NewtonContactJointGetNextContact(joint, contact)) {
				NewtonMaterial* material = NewtonContactGetMaterial(contact);
				dVector force;
				NewtonMaterialGetContactForce(material, body1, &force[0]);
				net_force += force;
			}
		}
	}
	const NewtonWorld* world = NewtonBodyGetWorld(body1);
	WorldData* world_data = (WorldData*)NewtonWorldGetUserData(world);
	//BodyData* body1_data = (BodyData*)NewtonBodyGetUserData(body1);
	//BodyData* body2_data = (BodyData*)NewtonBodyGetUserData(body2);
	/*if (world_data->gravity_enabled && (body1_data->gravity_enabled || body2_data->gravity_enabled)) {
		for (int i = 0; i < 3; ++i)
			net_force[i] *= world_data->inverse_scale;
	}*/
	return Util::vector_to_value(net_force, world_data->inverse_scale4);
}
	static void MagneticField (const NewtonJoint* contactJoint, dFloat timestep, int threadIndex)
	{
		dFloat magnetStregnth;
		const NewtonBody* body0;
		const NewtonBody* body1; 
		const NewtonBody* magneticField;
		const NewtonBody* magneticPiece;

		body0 = NewtonJointGetBody0 (contactJoint);
		body1 = NewtonJointGetBody1 (contactJoint);

		// get the magnetic field body
		magneticPiece = body0;
		magneticField = body1;
		if (NewtonCollisionIsTriggerVolume (NewtonBodyGetCollision(body0))) {
			magneticPiece = body1;
			magneticField = body0;
		}
		_ASSERTE (NewtonCollisionIsTriggerVolume (NewtonBodyGetCollision(magneticField)));

		// calculate the magnetic force field

		dMatrix center;
		dMatrix location;

		NewtonBodyGetMatrix (magneticField, &center[0][0]);
		NewtonBodyGetMatrix (magneticPiece, &location[0][0]);

		Magnet* magnet;
		magnet = (Magnet*)NewtonBodyGetUserData(magneticField);

		magnetStregnth = magnet->m_magnetStregnth;

		// calculate the magnetic force;

		dFloat den;
		dVector force (center.m_posit - location.m_posit);

		den = force % force;
		den = magnetStregnth / (den * dSqrt (den) + 0.1f);
		force = force.Scale (den);

		// because we are modifiing one of the bodies membber in the call back, there uis a chace that 
		// another materail can be operations on the same object at the same time of aother thread
		// therfore we need to make the assigmnet in a critical section.
		NewtonWorldCriticalSectionLock (NewtonBodyGetWorld (magneticPiece));
		
		// add the magner force
		NewtonBodyAddForce (magneticPiece, &force[0]);

		force = force.Scale (-1.0f);
		NewtonBodyAddForce (magnet->m_magneticCore, &force[0]);

		// also if the body is sleeping fore it to wake up for this frame
		NewtonBodySetFreezeState (magneticPiece, 0);
		NewtonBodySetFreezeState (magnet->m_magneticCore, 0);

		// unlock the critical section
		NewtonWorldCriticalSectionUnlock (NewtonBodyGetWorld (magneticPiece));
	}
static void OnGettingTheCollisionSubShapeFromMaterialCallback (const NewtonJoint* const contactJoint, dFloat timestep, int threadIndex)
{
	NewtonBody* const body0 = NewtonJointGetBody0(contactJoint);
	GetCollisionSubShape(contactJoint, body0);

	NewtonBody* const body1 = NewtonJointGetBody1(contactJoint);
	GetCollisionSubShape(contactJoint, body1);
}
Example #12
0
// return the collision joint, if the body collide
NewtonJoint* CheckIfBodiesCollide (NewtonBody* const body0, NewtonBody* const body1)
{
	for (NewtonJoint* joint = NewtonBodyGetFirstContactJoint (body0); joint; joint = NewtonBodyGetNextContactJoint (body0, joint)) {
		if ((NewtonJointGetBody0(joint) == body1) || (NewtonJointGetBody1(joint) == body1)) {
			return joint;
		}
	}
	return NULL;
}
Example #13
0
void GetContactOnBody (NewtonBody* const body)
{
	for (NewtonJoint* joint = NewtonBodyGetFirstContactJoint (body); joint; joint = NewtonBodyGetNextContactJoint (body, joint)) {
		NewtonBody* const body0 = NewtonJointGetBody0(joint);
		NewtonBody* const body1 = NewtonJointGetBody1(joint);
		for (void* contact = NewtonContactJointGetFirstContact (joint); contact; contact = NewtonContactJointGetNextContact (joint, contact)) {
			NewtonMaterial* material = NewtonContactGetMaterial (contact);

			//dFloat forceMag;
			dVector point;
			dVector normal;	
			//NewtonMaterialGetContactForce (material, &forceMag);
			NewtonMaterialGetContactPositionAndNormal (material, body1, &point.m_x, &normal.m_x);
			NewtonMaterialGetContactPositionAndNormal (material, body0, &point.m_x, &normal.m_x);
			// do whatever you want with the force
		}
	}
}
Example #14
0
//to get the collision points
void HandlecollisionPoints (NewtonJoint* const contactjoint)
{
	NewtonBody* const body0 = NewtonJointGetBody0(contactjoint);
	NewtonBody* const body1 = NewtonJointGetBody1(contactjoint);
	for (void* contact = NewtonContactJointGetFirstContact (contactjoint); contact; contact = NewtonContactJointGetNextContact (contactjoint, contact)) {

		NewtonMaterial* material = NewtonContactGetMaterial (contact);

		// do whatever you want here
		//dFloat forceMag;
		dVector point;
		dVector normal;	
		//NewtonMaterialGetContactForce (material, &forceMag);
		NewtonMaterialGetContactPositionAndNormal (material, body0, &point.m_x, &normal.m_x);
		NewtonMaterialGetContactPositionAndNormal (material, body1, &point.m_x, &normal.m_x);

		// do whatever you want with the force
	}
}
Example #15
0
void PhysicsWorld::onContactCallback(const NewtonJoint* contactJoint, F32 timestep, int threadIndex)
{
	const NewtonBody* body0 = NewtonJointGetBody0(contactJoint);
	const NewtonBody* body1 = NewtonJointGetBody1(contactJoint);

	F32 friction0 = 0.01;
	F32 elasticity0 = 0.001;
	F32 friction1 = friction0;
	F32 elasticity1 = elasticity0;

	void* userData = NewtonBodyGetUserData(body0);
	if(userData)
	{
		friction0 = static_cast<PhysicsBody*>(userData)->getFriction();
		elasticity0 = static_cast<PhysicsBody*>(userData)->getElasticity();
	}

	userData = NewtonBodyGetUserData(body1);
	if(userData)
	{
		friction1 = static_cast<PhysicsBody*>(userData)->getFriction();
		elasticity1 = static_cast<PhysicsBody*>(userData)->getElasticity();
	}

	F32 friction = friction0 + friction1;
	F32 elasticity = elasticity0 + elasticity1;

	void* contact = NewtonContactJointGetFirstContact(contactJoint);
	while(contact)
	{
		NewtonMaterial* material = NewtonContactGetMaterial(contact);

		NewtonMaterialSetContactFrictionCoef(material, friction + 0.1, friction, 0);
		NewtonMaterialSetContactFrictionCoef(material, friction + 0.1, friction, 1);

		NewtonMaterialSetContactElasticity(material, elasticity);

		contact = NewtonContactJointGetNextContact(contactJoint, contact);
	}
}
Example #16
0
void applyCarCollisionForce(const NewtonJoint* contact, dFloat timestep, int threadIndex) {
    void * userData1 = NewtonBodyGetUserData(NewtonJointGetBody0(contact));
    void * userData2 = NewtonBodyGetUserData(NewtonJointGetBody1(contact));
    if(userData1 == 0 || userData2 == 0) {
        return;
    }
    Car * car1 = (Car *)userData1;
    Car * car2 = (Car *)userData2;
    NewtonJoint * carContact = (NewtonJoint *) NewtonContactJointGetFirstContact(contact);
    do {
        dFloat collisionSpeed = NewtonMaterialGetContactNormalSpeed(
                                    NewtonContactGetMaterial(carContact)
                                );
        collisionSpeed = dAbs(collisionSpeed);

        if(collisionSpeed > 3) {
            car1->applyDamagePoints(collisionSpeed);
            car2->applyDamagePoints(collisionSpeed);
            break;
        }
        carContact = (NewtonJoint *) NewtonContactJointGetNextContact(contact, carContact);
    } while(carContact);
}
static void UserContactRestitution (const NewtonJoint* contactJoint, dFloat timestep, int threadIndex)
{
	// call  the basic call back
	GenericContactProcess (contactJoint, timestep, threadIndex);

	const NewtonBody* const body0 = NewtonJointGetBody0(contactJoint);
	const NewtonBody* const body1 = NewtonJointGetBody1(contactJoint);

	//now core 3.14 can have per collision user data
	const NewtonCollision* const collision0 = NewtonBodyGetCollision(body0);
	const NewtonCollision* const collision1 = NewtonBodyGetCollision(body1);

	NewtonCollisionMaterial material0;
	NewtonCollisionMaterial material1;
	NewtonCollisionGetMaterial(collision0, &material0);
	NewtonCollisionGetMaterial(collision1, &material1);
	dAssert((material0.m_userId == 1) || (material1.m_userId == 1));
	dFloat restitution = dMax(material0.m_userParam[0], material1.m_userParam[0]);

	for (void* contact = NewtonContactJointGetFirstContact (contactJoint); contact; contact = NewtonContactJointGetNextContact (contactJoint, contact)) {
		NewtonMaterial* const material = NewtonContactGetMaterial (contact);
		NewtonMaterialSetContactElasticity (material, restitution);
	}
}
	void PhysWorld3D::ProcessContact(const NewtonJoint* const contactJoint, float timestep, int threadIndex)
	{
		RigidBody3D* bodyA = static_cast<RigidBody3D*>(NewtonBodyGetUserData(NewtonJointGetBody0(contactJoint)));
		RigidBody3D* bodyB = static_cast<RigidBody3D*>(NewtonBodyGetUserData(NewtonJointGetBody1(contactJoint)));
		assert(bodyA && bodyB);

		using ContactJoint = void*;

		// Query all joints first, to prevent removing a joint from the list while iterating on it
		StackVector<ContactJoint> contacts = NazaraStackVector(ContactJoint, NewtonContactJointGetContactCount(contactJoint));
		for (ContactJoint contact = NewtonContactJointGetFirstContact(contactJoint); contact; contact = NewtonContactJointGetNextContact(contactJoint, contact))
			contacts.push_back(contact);

		for (ContactJoint contact : contacts)
		{
			NewtonMaterial* material = NewtonContactGetMaterial(contact);
			Callback* callbackData = static_cast<Callback*>(NewtonMaterialGetMaterialPairUserData(material));
			assert(callbackData);
			assert(callbackData->collisionCallback);

			if (!callbackData->collisionCallback(*bodyA, *bodyB))
				NewtonContactJointRemoveContact(contactJoint, contact);
		}
	}
	void cPhysicsMaterialNewton::ProcessContactCallback(const NewtonJoint* apJoint,
													   float afTimeStep,
													   int alThreadIndex)
	{
		cPhysicsContactData ContactData;
		int lContactNum = 0;
		iPhysicsBody * pContactBody1 = (iPhysicsBody*) NewtonBodyGetUserData(NewtonJointGetBody0(apJoint));
		iPhysicsBody * pContactBody2 = (iPhysicsBody*) NewtonBodyGetUserData(NewtonJointGetBody1(apJoint));

		for (void* pContact = NewtonContactJointGetFirstContact(apJoint);
			 pContact;
			 pContact = NewtonContactJointGetNextContact(apJoint, pContact))
		{
			NewtonMaterial* pMaterial = NewtonContactGetMaterial(pContact);
			//Log(" Process contact between body '%s' and '%s'.\n",pContactBody1->GetName().c_str(),
			//													pContactBody2->GetName().c_str());

			//Normal speed
			float fNormSpeed = NewtonMaterialGetContactNormalSpeed(pMaterial);
			if (ContactData.mfMaxContactNormalSpeed < fNormSpeed)
				ContactData.mfMaxContactNormalSpeed = fNormSpeed;

			//Tangent speed
			float fTanSpeed0 = NewtonMaterialGetContactTangentSpeed(pMaterial, 0);
			float fTanSpeed1 = NewtonMaterialGetContactTangentSpeed(pMaterial, 1);
			if(std::abs(ContactData.mfMaxContactTangentSpeed) < std::abs(fTanSpeed0))
				ContactData.mfMaxContactTangentSpeed = fTanSpeed0;
			if(std::abs(ContactData.mfMaxContactTangentSpeed) < std::abs(fTanSpeed1))
				ContactData.mfMaxContactTangentSpeed = fTanSpeed1;

			//Force
			cVector3f vForce;
			NewtonMaterialGetContactForce(pMaterial,vForce.v);
			ContactData.mvForce += vForce;

			//Position and normal
			cVector3f vPos, vNormal;
			NewtonMaterialGetContactPositionAndNormal(pMaterial,vPos.v, vNormal.v);

			ContactData.mvContactNormal += vNormal;
			ContactData.mvContactPosition += vPos;

			//Log(" Norm: %f Tan0: %f Tan1: %f\n",fNormSpeed, fTanSpeed0, fTanSpeed1);
			//Log("Force: %s step %f\n", vForce.ToString().c_str(), afTimestep);

			if(pContactBody1->GetWorld()->GetSaveContactPoints())
			{
				cCollidePoint collidePoint;
				collidePoint.mfDepth = 1;
				NewtonMaterialGetContactPositionAndNormal (pMaterial, collidePoint.mvPoint.v,
														   collidePoint.mvNormal.v);

				pContactBody1->GetWorld()->GetContactPoints()->push_back(collidePoint);
			}

			lContactNum++;
		}

		//Log("--- End contact between body '%s' and '%s'.\n",mpContactBody1->GetName().c_str(),
		//													mpContactBody2->GetName().c_str());

		if(lContactNum <= 0) return;

		iPhysicsMaterial *pMaterial1 = pContactBody1->GetMaterial();
		iPhysicsMaterial *pMaterial2 = pContactBody2->GetMaterial();

		ContactData.mvContactNormal = ContactData.mvContactNormal / (float)lContactNum;
		ContactData.mvContactPosition = ContactData.mvContactPosition / (float)lContactNum;

		pMaterial1->GetSurfaceData()->CreateImpactEffect(ContactData.mfMaxContactNormalSpeed,
													ContactData.mvContactPosition,
													lContactNum,pMaterial2->GetSurfaceData());

		int lPrio1 = pMaterial1->GetSurfaceData()->GetPriority();
		int lPrio2 = pMaterial2->GetSurfaceData()->GetPriority();

		if(lPrio1 >= lPrio2)
		{
			if(std::abs(ContactData.mfMaxContactNormalSpeed) > 0)
				pMaterial1->GetSurfaceData()->OnImpact(ContactData.mfMaxContactNormalSpeed,
														ContactData.mvContactPosition,
														lContactNum,pContactBody1);
			if(std::abs(ContactData.mfMaxContactTangentSpeed) > 0)
				pMaterial1->GetSurfaceData()->OnSlide(ContactData.mfMaxContactTangentSpeed,
														ContactData.mvContactPosition,
														lContactNum,pContactBody1,pContactBody2);
		}

		if(lPrio2 >= lPrio1 && pMaterial2 != pMaterial1)
		{
			if(std::abs(ContactData.mfMaxContactNormalSpeed) > 0)
				pMaterial2->GetSurfaceData()->OnImpact(ContactData.mfMaxContactNormalSpeed,
														ContactData.mvContactPosition,
														lContactNum,pContactBody2);
			if(std::abs(ContactData.mfMaxContactTangentSpeed) > 0)
				pMaterial2->GetSurfaceData()->OnSlide(ContactData.mfMaxContactTangentSpeed,
														ContactData.mvContactPosition,
														lContactNum,pContactBody2,pContactBody1);
		}

		pContactBody1->OnCollide(pContactBody2,&ContactData);
		pContactBody2->OnCollide(pContactBody1,&ContactData);
	}
		void ApplyTracktionForce (dFloat timestep, const NewtonBody* track)
		{
			dVector veloc;
			dVector omega;
			dMatrix matrix;

			NewtonBodyGetOmega(m_body0, &omega[0]);
			NewtonBodyGetVelocity(m_body0, &veloc[0]);
			NewtonBodyGetMatrix (m_body0, &matrix[0][0]);
			

			// itetate over the contact list and condition each contact direction anc contact acclerations
			for (NewtonJoint* contactJoint = NewtonBodyGetFirstContactJoint (track); contactJoint; contactJoint = NewtonBodyGetNextContactJoint (track, contactJoint)) {
				_ASSERTE ((NewtonJointGetBody0 (contactJoint) == track) || (NewtonJointGetBody1 (contactJoint) == track));

				#ifdef REMOVE_REDUNDAT_CONTACT	
				int contactCount;
				contactCount = NewtonContactJointGetContactCount(contactJoint);
				if (contactCount > 2) {
					// project the contact to the bounday of the conve hull o fteh trhread foot ptint 
					dFloat maxDist;
					dFloat minDist;
					void* minContact;
					void* maxContact;
					
					dMatrix matrix;
			
					minContact = NULL;
				    maxContact = NULL;
					NewtonBodyGetMatrix (track, &matrix[0][0]);

					maxDist = -1.0e10f;
					minDist = -1.0e10f;
					//find the best two contacts and remove all others
					for (void* contact = NewtonContactJointGetFirstContact (contactJoint); contact; contact = NewtonContactJointGetNextContact (contactJoint, contact)) {
						dFloat dist;
						dVector point;
						dVector normal;
						NewtonMaterial* material;

					    material = NewtonContactGetMaterial (contact);
						NewtonMaterialGetContactPositionAndNormal(material, &point[0], &normal[0]);
						
						dist = matrix.m_front % point;
						if (dist > maxDist) {
							maxDist = dist;
							maxContact = contact;
						} 
						if (-dist > minDist) {
							minDist = -dist;
							minContact = contact;
						}
						
					}

					// now delete all reduntact contacts
					void* nextContact;
					NewtonWorld* world;

					world = NewtonBodyGetWorld (track);
					NewtonWorldCriticalSectionLock(world);
					for (void* contact = NewtonContactJointGetFirstContact (contactJoint); contact; contact = nextContact) {
						nextContact = NewtonContactJointGetNextContact (contactJoint, contact);
						if (!((contact == minContact) || (contact == maxContact))) {
							NewtonContactJointRemoveContact (contactJoint, contact);
						}
					}
					NewtonWorldCriticalSectionUnlock(world);
				}

				#endif

			
				for (void* contact = NewtonContactJointGetFirstContact (contactJoint); contact; contact = NewtonContactJointGetNextContact (contactJoint, contact)) {
					dFloat speed;
					dFloat accel;
					dVector point;
					dVector normal;
					dVector dir0;
					dVector dir1;
					NewtonMaterial* material;

				    material = NewtonContactGetMaterial (contact);
					NewtonMaterialContactRotateTangentDirections (material, &matrix.m_front[0]);
					NewtonMaterialGetContactPositionAndNormal(material, &point[0], &normal[0]);
					NewtonMaterialGetContactTangentDirections (material, &dir0[0], &dir1[0]);


					dVector posit (point - matrix.m_posit);
					veloc += omega * posit;
					speed = veloc % dir0;
				//	accel = m_accel - 0.1f * speed + (((posit % m_matrix.m_right) > 0.0f) ? m_turnAccel : - m_turnAccel);
					accel = m_veloc + (((posit % matrix.m_right) > 0.0f) ? m_turnVeloc : - m_turnVeloc);

					accel = (accel - speed) * 0.5f / timestep;

			//		NewtonMaterialSetContactStaticFrictionCoef (material, 1.0f, 0);
			//		NewtonMaterialSetContactKineticFrictionCoef (material, 1.0f, 0);
					NewtonMaterialSetContactFrictionCoef (material, 1.0f, 1.0f, 0);

			//		NewtonMaterialSetContactStaticFrictionCoef (material, 0.5f, 1);
			//		NewtonMaterialSetContactKineticFrictionCoef (material, 0.5f, 1);
					NewtonMaterialSetContactFrictionCoef (material, 0.5f, 0.5f, 1);
					
					NewtonMaterialSetContactTangentAcceleration (material, accel, 0);
				}

				// for debug purpose show the contact
				ShowJointContacts (contactJoint);
			}
		}
dNewtonBody* dNewtonContactMaterial::GetBody1 () const
{
	NewtonBody* const body = NewtonJointGetBody1 ((NewtonJoint*)m_materialHandle);
	return (dNewtonBody*) NewtonBodyGetUserData (body);
}