Physics Simulation Forum

 

All times are UTC




Post new topic Reply to topic  [ 2 posts ] 
Author Message
PostPosted: Fri Jun 16, 2017 5:08 pm 
Offline

Joined: Sun Jan 22, 2017 5:41 pm
Posts: 4
I'm trying to use btRaycastVehicle in my opengl engine. Bullet world space coordinate system is the same as opengl world space coordinate system, i.e. -z axis goes forward (right handed). btTransform places rigid bodies as I expect.

When I add the engine force:
Code:
physicsEngine.getVehicle()->applyEngineForce(500, 2);
physicsEngine.getVehicle()->applyEngineForce(500, 3);
the vehicle moves in +z direction but wheels don't rotate.

A third parameter of addWheel function(wheelAxleCS) is defined as [-1, 0, 0]. I have noticed that by default a vehicle forward vector (vehicle->getForwardVector()) is defined as [0, 1, 0], so how it is possible that the car moves in +z direction at all?
How to achieve a movement in -z direction and wheels rotation?

I get transformations this way:
Code:
//vehicle body
vehicle->getRigidBody()->getMotionState()->getWorldTransform(transform);
transform.getOpenGLMatrix(mat);
//for each wheel
vehicle->updateWheelTransform(index, true);
transform = vehicle->getWheelInfo(index).m_worldTransform;
transform.getOpenGLMatrix(mat);


Top
 Profile  
 
PostPosted: Sat Jun 17, 2017 4:11 pm 
Offline

Joined: Sun Jan 22, 2017 5:41 pm
Posts: 4
When I set the vehicle coordinate system this way:
Code:
int rightIndex = 0;
int upIndex = 1;
int forwardIndex = 2;
physicsEngine.getVehicle()->setCoordinateSystem(rightIndex,upIndex,forwardIndex);

then the forward vector is [0,0,1] and the car moves in +z direction with correct wheels rotation but I have still following questions:
- Why the car move in +z direction without wheels rotation when forward vector is [0,1,0] ?
- How to achieve movement in -z direction ?


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 

All times are UTC


Who is online

Users browsing this forum: Baidu [Spider] and 15 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group