Search found 7 matches

by Tadek
Tue Feb 12, 2019 8:02 pm
Forum: General Bullet Physics Support and Feedback
Topic: raycast vehicle - understanding coordinate system
Replies: 0
Views: 218

raycast vehicle - understanding coordinate system

Bullet world space coordinate system is the same as opengl world coordinate system. I have noticed that raycast vehicle has the following function: virtual void btRaycastVehicle::setCoordinateSystem(int rightIndex, int upIndex, int forwardIndex); How does that function work ? By default raycast vehi...
by Tadek
Sun Feb 10, 2019 8:54 pm
Forum: General Bullet Physics Support and Feedback
Topic: raycast vehicle - how wheel connection point and wheel width are defined
Replies: 1
Views: 180

Re: raycast vehicle - how wheel connection point and wheel width are defined

Wheel connection that's a vector from the chasis center to the wheel center. Matrix for the graphics engine is obtained this way: btTransform transform = vehicle_->getWheelInfo(wheelNumber).m_worldTransform; float openglMatrix[16]; transform.getOpenGLMatrix(openglMatrix); Raycast vehicle doesn't def...
by Tadek
Sat Feb 09, 2019 2:40 pm
Forum: General Bullet Physics Support and Feedback
Topic: raycast vehicle - how wheel connection point and wheel width are defined
Replies: 1
Views: 180

raycast vehicle - how wheel connection point and wheel width are defined

I create a raycast vehicle with a simple rectangular chassis rigid body. Box dimensions: [1, 1, 3]. btRaycastVehicle has addWheel function which has wheelConnectionPoint parameter. How it is defined ? Is it a position calculated from chassis rigid body center ? I also wonder how to define a wheel wi...
by Tadek
Sat Jun 17, 2017 4:11 pm
Forum: General Bullet Physics Support and Feedback
Topic: btRaycastVehicle - movement direction and wheels rotation
Replies: 1
Views: 1176

Re: btRaycastVehicle - movement direction and wheels rotatio

When I set the vehicle coordinate system this way: 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...
by Tadek
Fri Jun 16, 2017 5:08 pm
Forum: General Bullet Physics Support and Feedback
Topic: btRaycastVehicle - movement direction and wheels rotation
Replies: 1
Views: 1176

btRaycastVehicle - movement direction and wheels rotation

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: physicsEngine.getVehicle()->applyEngin...
by Tadek
Wed Feb 01, 2017 7:38 pm
Forum: General Bullet Physics Support and Feedback
Topic: object (rigid body) stabilization after picking
Replies: 2
Views: 1493

Re: object (rigid body) stabilization after picking

What about p2p constraint settings ? A default settings from CommonRigidBodyBase look like this: p2p->m_setting.m_impulseClamp = 30.f; p2p->m_setting.m_tau = 0.001f; I found following definitions: - the m_impulseClamp value controls how quickly the dynamic rigid body comes to rest - the m_damping va...
by Tadek
Fri Jan 27, 2017 6:05 pm
Forum: General Bullet Physics Support and Feedback
Topic: object (rigid body) stabilization after picking
Replies: 2
Views: 1493

object (rigid body) stabilization after picking

Many of the bullet examples inherit from CommonRigidBodyBase. Objects are picked based on btPoint2PointConstraint. I have analyzed a SimpleBox example. When a falling object is picked it starts rotate around a pick point but rotation decreases with time. After some time a picked object should become...