Ray Cast Vehicle not colliding with ground

[dumbo2007]

I am trying to make a simple demo based on the VehicleDemo sample project provided with the SDK. At the moment I am simply trying to add a btRaycastVehicle and solid ground to the dynamics world. But after adding the vehicle and ground , when I step the physics world, then the vehicle seems to fall straight through. Here is my code(its in a class called BulletVehicle)

Code: Select all

//Car and wheel properties
#define CUBE_HALF_EXTENTS 1
int rightIndex = 0;
int upIndex = 1;
int forwardIndex = 2;
btVector3 wheelDirectionCS0(0,-1,0);
btVector3 wheelAxleCS(-1,0,0);

float	gEngineForce = 0.f;
float	gBreakingForce = 0.f;

float	maxEngineForce = 1000.f;//this should be engine/velocity dependent
float	maxBreakingForce = 100.f;

float	gVehicleSteering = 0.f;
float	steeringIncrement = 0.04f;
float	steeringClamp = 0.3f;
float	wheelRadius = 0.5f;
float	wheelWidth = 0.4f;
float	wheelFriction = 1000;//BT_LARGE_FLOAT;
float	suspensionStiffness = 20.f;
float	suspensionDamping = 2.3f;
float	suspensionCompression = 4.4f;
float	rollInfluence = 0.1f;//1.0f;

btScalar suspensionRestLength(0.6);

void	BulletVehicle::initPhysics()
{
	int i;	

	btCollisionShape* groundShape = new btBoxShape(btVector3(50,3,50));
	m_collisionShapes.push_back(groundShape);
	m_collisionConfiguration = new btDefaultCollisionConfiguration();
	m_dispatcher = new btCollisionDispatcher(m_collisionConfiguration);
	btVector3 worldMin(-1000,-1000,-1000);
	btVector3 worldMax(1000,1000,1000);
	m_overlappingPairCache = new btAxisSweep3(worldMin,worldMax);//add
	m_constraintSolver = new btSequentialImpulseConstraintSolver();
	m_dynamicsWorld = new   btDiscreteDynamicsWorld(m_dispatcher,m_overlappingPairCache,m_constraintSolver,m_collisionConfiguration);


	//m_dynamicsWorld->setGravity(btVector3(0,0,0));
	btTransform tr;
	tr.setIdentity();

	//create ground collision shape
	groundShape = new btStaticPlaneShape(btVector3(0,1,0),1);
       m_collisionShapes.push_back(groundShape);

	//create ground object
	localCreateRigidBody(0,btTransform(btQuaternion(0,0,0,1),btVector3(0,-10,0)),groundShape);


	btCollisionShape* chassisShape = new btBoxShape(btVector3(1.f,0.5f,2.f));
	m_collisionShapes.push_back(chassisShape);

	btCompoundShape* compound = new btCompoundShape();
	m_collisionShapes.push_back(compound);
	btTransform localTrans;
	localTrans.setIdentity();
	//localTrans effectively shifts the center of mass with respect to the chassis
	localTrans.setOrigin(btVector3(0,1,0));


	compound->addChildShape(localTrans,chassisShape);

	//Start making car : position is below
	tr.setOrigin(btVector3(0,10.f,0));
	m_carChassis = localCreateRigidBody(800,tr,compound);//chassisShape);
	//m_carChassis->setDamping(0.2,0.2);
	
	m_wheelShape = new btCylinderShapeX(btVector3(wheelWidth,wheelRadius,wheelRadius));

	// create vehicle
	{
		
		m_vehicleRayCaster = new btDefaultVehicleRaycaster(m_dynamicsWorld);
		m_vehicle = new btRaycastVehicle(m_tuning,m_carChassis,m_vehicleRayCaster);
		
		//never deactivate the vehicle
		m_carChassis->setActivationState(DISABLE_DEACTIVATION);

		m_dynamicsWorld->addVehicle(m_vehicle);


		//Now for the wheels : choose coordinate system
		m_vehicle->setCoordinateSystem(rightIndex,upIndex,forwardIndex);
		float connectionHeight = 1.2f;
		
		//Front wheels : only affected by steering
		bool isFrontWheel=true;
		btVector3 connectionPointCS0(CUBE_HALF_EXTENTS-(0.3*wheelWidth),connectionHeight,2*CUBE_HALF_EXTENTS-wheelRadius);
		m_vehicle->addWheel(connectionPointCS0,wheelDirectionCS0,wheelAxleCS,suspensionRestLength,wheelRadius,m_tuning,isFrontWheel);

		connectionPointCS0 = btVector3(-CUBE_HALF_EXTENTS+(0.3*wheelWidth),connectionHeight,2*CUBE_HALF_EXTENTS-wheelRadius);
		m_vehicle->addWheel(connectionPointCS0,wheelDirectionCS0,wheelAxleCS,suspensionRestLength,wheelRadius,m_tuning,isFrontWheel);
		
		//Back wheels : only affected by engines
		isFrontWheel = false;
		connectionPointCS0 = btVector3(-CUBE_HALF_EXTENTS+(0.3*wheelWidth),connectionHeight,-2*CUBE_HALF_EXTENTS+wheelRadius);
		m_vehicle->addWheel(connectionPointCS0,wheelDirectionCS0,wheelAxleCS,suspensionRestLength,wheelRadius,m_tuning,isFrontWheel);

		connectionPointCS0 = btVector3(CUBE_HALF_EXTENTS-(0.3*wheelWidth),connectionHeight,-2*CUBE_HALF_EXTENTS+wheelRadius);
		m_vehicle->addWheel(connectionPointCS0,wheelDirectionCS0,wheelAxleCS,suspensionRestLength,wheelRadius,m_tuning,isFrontWheel);
		
		//Wheel properties : adjust globals
		for (int i=0;i<m_vehicle->getNumWheels();i++)
		{
			btWheelInfo& wheel = m_vehicle->getWheelInfo(i);
			wheel.m_suspensionStiffness = suspensionStiffness;
			wheel.m_wheelsDampingRelaxation = suspensionDamping;
			wheel.m_wheelsDampingCompression = suspensionCompression;
			wheel.m_frictionSlip = wheelFriction;
			wheel.m_rollInfluence = rollInfluence;
		}
	}

	
	//setCameraDistance(26.f);
	

}

I take care of the rendering myself using opengl. So when I try to render the wheels, they appear in the correct position and also turn as directed. But the chassis is not rendering correctly. I render the wheels and chassis like this(I havent yet rendered all sides of the chassis cuboid, but I ll do that once I am certain it will appear in the right position) :

Code: Select all

//draw the chassis
		glColor3f(1, 1, 0);
		m_vehicle->getChassisWorldTransform().getOpenGLMatrix(m);
		glMultMatrixf(m);	
		glBegin(GL_QUADS);							// Start Drawing A Textured Quad
			glVertex3f(-0.5f, 0.25f,  1.0f);	// Bottom Left
			glVertex3f( 0.5f, 0.25f,  1.0f);	// Bottom Right
			glVertex3f( 0.5f, -0.25f,  1.0f);	// Top Right
			glVertex3f( -0.5f, -0.25f, 1.0f);	// Top Left
		glEnd();	
				
		
		glColor3f(1, 1, 1);	
		glEnable(GL_TEXTURE_2D);
		glBindTexture(GL_TEXTURE_2D, texture[0]);
		for (i=0;i<m_vehicle->getNumWheels();i++){
			//synchronize the wheels with the (interpolated) chassis worldtransform
			m_vehicle->updateWheelTransform(i,true);
			//draw wheels (cylinders)
			m_vehicle->getWheelInfo(i).m_worldTransform.getOpenGLMatrix(m);
			//m_shapeDrawer->drawOpenGL(m,m_wheelShape,wheelColor,getDebugMode(),worldBoundsMin,worldBoundsMax);

			//draw cylinder by pushing current matrix and mult m
			
			glPushMatrix();
				glMultMatrixf(m);			
				gluSphere(quadratic,1.0f,16,16);
			glPopMatrix();
		}	

Here is a picture of the render :


I have attached the code for the class BulletVehicle which initializes the physics world and uses opengl for rendering.