void CarHandlingDemo::addWheels(
btVector3* halfExtents,
btRaycastVehicle* vehicle,
btRaycastVehicle::btVehicleTuning tuning)
{
//The direction of the raycast, the btRaycastVehicle uses raycasts instead of simiulating the wheels with rigid bodies
btVector3 wheelDirectionCS0(0, -1, 0);
//The axis which the wheel rotates arround
btVector3 wheelAxleCS(-1, 0, 0);
btScalar suspensionRestLength(0.7);
btScalar wheelWidth(0.4);
btScalar wheelRadius(0.5);
//The height where the wheels are connected to the chassis
btScalar connectionHeight(1.2);
//All the wheel configuration assumes the vehicle is centered at the origin and a right handed coordinate system is used
btVector3 wheelConnectionPoint(halfExtents->x() - wheelRadius, connectionHeight, halfExtents->z() - wheelWidth);
//Adds the front wheels
vehicle->addWheel(wheelConnectionPoint, wheelDirectionCS0, wheelAxleCS, suspensionRestLength, wheelRadius, tuning, true);
vehicle->addWheel(wheelConnectionPoint * btVector3(-1, 1, 1), wheelDirectionCS0, wheelAxleCS, suspensionRestLength, wheelRadius, tuning, true);
//Adds the rear wheels
vehicle->addWheel(wheelConnectionPoint* btVector3(1, 1, -1), wheelDirectionCS0, wheelAxleCS, suspensionRestLength, wheelRadius, tuning, false);
vehicle->addWheel(wheelConnectionPoint * btVector3(-1, 1, -1), wheelDirectionCS0, wheelAxleCS, suspensionRestLength, wheelRadius, tuning, false);
//Configures each wheel of our vehicle, setting its friction, damping compression, etc.
//For more details on what each parameter does, refer to the docs
for (int i = 0; i < vehicle->getNumWheels(); i++)
{
btWheelInfo& wheel = vehicle->getWheelInfo(i);
wheel.m_suspensionStiffness = 50;
wheel.m_wheelsDampingCompression = btScalar(0.3) * 2 * btSqrt(wheel.m_suspensionStiffness);//btScalar(0.8);
wheel.m_wheelsDampingRelaxation = btScalar(0.5) * 2 * btSqrt(wheel.m_suspensionStiffness);//1;
//Larger friction slips will result in better handling
wheel.m_frictionSlip = btScalar(1.2);
wheel.m_rollInfluence = 1;
}
}
bool Vehicle::LoadContent(DxGraphics* dx, ResourceManager& resources)
{
m_dynamicsWorld = resources.GetPhysicsManager()->GetWorld();
//Loads the content of all the modules
if (!m_body->LoadContent(dx, m_body->GetPosition(), resources, m_body->GetYaw(), m_body->GetPitch(),
m_body->GetRoll(), m_scale + m_body->GetScale()))
{
return false;
}
for (unsigned int i = 0; i < 4; i++)
{
if (i == 0 || i == 1)
{
if (!m_retros[i]->LoadContent(dx, m_retros[i]->GetPosition(), resources, m_retros[i]->GetYaw(),
m_retros[i]->GetPitch(), m_retros[i]->GetRoll(), m_scale + m_retros[i]->GetScale()))
{
return false;
}
}
if (!m_wheels[i]->LoadContent(dx, m_wheels[i]->GetPosition(), resources, m_wheels[i]->GetYaw(),
m_wheels[i]->GetPitch(), m_wheels[i]->GetRoll(), m_scale + m_wheels[i]->GetScale()))
{
return false;
}
}
if (!m_spoiler->LoadContent(dx, m_spoiler->GetPosition(), resources, m_spoiler->GetYaw(),
m_spoiler->GetPitch(), m_spoiler->GetRoll(), m_scale + m_spoiler->GetScale()))
{
return false;
}
//ASSIGN CAR INFORMATION
m_vehicleInfo.m_engineForce = m_retros[0]->engineForce;
m_vehicleInfo.m_defaultEngineForce = m_retros[0]->engineForce;
m_vehicleInfo.m_frictionSlip = BT_LARGE_FLOAT;
m_vehicleInfo.m_rollInfluence = 0.0001f;
m_vehicleInfo.m_suspensionRestLength1 = 0.2f;
m_vehicleInfo.m_suspensionStiffness = 40.0f;
m_vehicleInfo.m_wheelsDampingCompression = 4.4f; //4.4
m_vehicleInfo.m_wheelsDampingRelaxation = 10.2f; //20
m_vehicleInfo.m_steeringForce = 0.05f;
m_vehicleInfo.m_breakingForce = 100;
m_vehicleInfo.m_maxSteeringAngle = 0.10f;
//Calcualte mass of the car, based on components.
m_mass = m_body->GetWeight() + m_spoiler->GetWeight() + (m_wheels[0]->GetWeight() * 4) + (m_retros[0]->GetWeight() * 2);
//initialize the compound, start adding all the aprts together
m_vehicleCompound = new btCompoundShape();
//CREATE VEHICLE PARTS
//BODY
m_vehicleCompound->addChildShape(m_body->GetLocalTranslation(), m_body->CreateCollisionShape());
//RETROS
for (int x = 0; x < 2; x++)
{
m_vehicleCompound->addChildShape(m_retros[x]->GetLocalTranslation(), m_retros[x]->CreateCollisionShape());
}
//SPOILER
m_vehicleCompound->addChildShape(m_spoiler->GetLocalTranslation(), m_spoiler->CreateCollisionShape());
//set the car Transform
btTransform tr;
tr.setIdentity();
tr.setOrigin(btVector3(m_position.x, m_position.y, m_position.z));
//Combine all the parts into a rigid body object.
m_rigidBody = localCreateRigidBody(m_mass, tr, m_vehicleCompound);
/// Create raycasting for the vechicle and attach it to the car
{
m_vehicleRayCaster = new btDefaultVehicleRaycaster(m_dynamicsWorld);
m_vehicle = new btRaycastVehicle(m_tuning, m_rigidBody, m_vehicleRayCaster);
///never deactivate the vehicle
m_rigidBody->setActivationState(DISABLE_DEACTIVATION);
//add the vehicle to the simualtion.
m_dynamicsWorld->addVehicle(m_vehicle);
//Set up coordiante system , Y-up, Z-forward
int rightIndex = 0;
int upIndex = 1;
int forwardIndex = 2;
m_vehicle->setCoordinateSystem(rightIndex, upIndex, forwardIndex);
bool isFrontWheel = true;
btVector3 wheelDirectionCS0(0.0f, -1.0f, 0.0f);
btVector3 wheelAxleCS(-1.0f, 0.0f, 0.0f);
btScalar suspensionRestLength(0.2f);
//initialize wheels
for (int x = 0; x < 4; x++)
{
XMFLOAT3 colExt = m_wheels[x]->GetCollisionExtents();
float wheelRadius = colExt.y;
float wheelWidth = colExt.z;
//determine which wheels are at the back
if (x > 2) isFrontWheel = false;
XMFLOAT3 offset = m_wheels[x]->GetOffset();
btVector3 connectionPointCS0 = btVector3(offset.x, offset.y, offset.z);
m_vehicle->addWheel(connectionPointCS0, wheelDirectionCS0, wheelAxleCS, suspensionRestLength, wheelRadius, m_tuning, isFrontWheel);
}
//Rotate the wheel for the other side.
m_wheels[1]->SetYaw(m_wheels[2]->GetYaw() + XM_PI);
m_wheels[3]->SetYaw(m_wheels[3]->GetYaw() + XM_PI);
//Wheel parameters.
for (int i = 0; i < m_vehicle->getNumWheels(); i++)
{
btWheelInfo& wheel = m_vehicle->getWheelInfo(i);
wheel.m_suspensionStiffness = m_vehicleInfo.m_suspensionStiffness;
wheel.m_wheelsDampingRelaxation = m_vehicleInfo.m_wheelsDampingRelaxation;
wheel.m_wheelsDampingCompression = m_vehicleInfo.m_wheelsDampingCompression;
wheel.m_frictionSlip = m_vehicleInfo.m_frictionSlip;
wheel.m_rollInfluence = m_vehicleInfo.m_rollInfluence;
wheel.m_suspensionRestLength1 = m_vehicleInfo.m_suspensionRestLength1;
}
}
m_loaded = true;
return true;
}
