get btCollisionShape current transform

2013-11-17T17:32:54+00:00

Hey guys,

I have made a compound shape

Code:

compound = new btCompoundShape();

Then I have a collision shape added to the compound:

Code:

btCollisionShape* turretShape = new btBoxShape(btVector3(0.4f, 0.2f, 1.2f));btTransform turretTrans;turretTrans.setIdentity();turretTrans.setOrigin(btVector3(0.0f, 2.2f, 0.0f));compound->addChildShape(turretTrans, turretShape);

The compund shape is then transformed into a rigid body and then added to a vehicle raycaster as a chassis:

Code:

m_carChassis = CreateRigidBody(2000, tr, compound);m_vehicle = new btRaycastVehicle(m_tuning, m_carChassis, m_vehicleRayCaster);

The vehicle is moving along, together with it's wheels, chassis and turret, but I cannot seem to get hold of the updated turret transform.
Whenever I try something like this:

Code:

compound->getChildTransform(1).getOpenGLMatrix(mturret);

I always get the initial position of the turret, where it was first created.

Now, for the wheels I can do this:

Code:

m_vehicle->getWheelInfo(i).m_worldTransform.getOpenGLMatrix(mwheel);

And for the chassis I can do this:

Code:

m_vehicle->getChassisWorldTransform().getOpenGLMatrix(mchassis);

But I don't know how do I get hold of that turret collision shape updated transform?

Please note that where I need this information I have access to both the compound and the turretShape (the actual btCollisionShape).

EDIT:

I found the answer. Here's what I did:

Code:

btTransform chassisMatrix = m_vehicle->getChassisWorldTransform();btTransform turretMatrix = compound->getChildTransform(1);turretMatrix *= chassisMatrix;turretMatrix.getOpenGLMatrix(mturret);

Statistics: Posted by b0gd4n — Sun Nov 17, 2013 5:32 pm

Real-Time Physics Simulation Forum

get btCollisionShape current transform