Search found 26 matches

by rrck
Sun Dec 13, 2009 11:20 am
Forum: Applications, Games, Demos or Movies using Bullet
Topic: Bullet integration with Cocos2D, review?
Replies: 3
Views: 4348

Re: Bullet integration with Cocos2D, review?

In latest Bullet trunk (or maybe even in 2.75 version) was introduced some improvements for 2D.
You can use setAngularFactor and setLinearFactor to limit velocities in desired axises, also was added 2D shapes, try to look Bullet/Demos/Box2dDemo
by rrck
Sat Dec 12, 2009 1:10 pm
Forum: General Bullet Physics Support and Feedback
Topic: Bounding Volume
Replies: 5
Views: 3031

Re: Bounding Volume

Hello, I'am only Bullet user, so I may be not fully correct. :) As I know AABB are used mostly for broadphase part of collision detection, and I have not noticed in documentation any mentions about possibility to use other bounding volumes (as I know AABB is most optimal for broadphase). May be you ...
by rrck
Sat Dec 12, 2009 12:33 pm
Forum: General Bullet Physics Support and Feedback
Topic: New issue with gContactAddedCallback in Bullet 2.75
Replies: 40
Views: 11490

Re: New issue with gContactAddedCallback in Bullet 2.75

indexId represents child id of compound shape. As I know partId is used for tri meshes to point which triangles array is collided.
by rrck
Wed Dec 09, 2009 7:08 pm
Forum: General Bullet Physics Support and Feedback
Topic: New issue with gContactAddedCallback in Bullet 2.75
Replies: 40
Views: 11490

Re: New issue with gContactAddedCallback in Bullet 2.75

I think that partId for compounds are always set to -1.
by rrck
Mon Dec 07, 2009 11:54 am
Forum: General Bullet Physics Support and Feedback
Topic: New issue with gContactAddedCallback in Bullet 2.75
Replies: 40
Views: 11490

Re: New issue with gContactAddedCallback in Bullet 2.75

I have filled new issue(316) in google.code. Issue includes small patch which fixed, this problem for me. But it was only tested for trimesh vs compunds, and I'am not 100% sure that this solutions is right :).
by rrck
Thu Nov 26, 2009 7:23 pm
Forum: General Bullet Physics Support and Feedback
Topic: Reseting dynamic object's motion?
Replies: 3
Views: 1655

Re: Reseting dynamic object's motion?

Try to set transform using setCenterOfMassTransform (instead of setTransform) after resetting velocities.
by rrck
Sat Nov 21, 2009 11:03 pm
Forum: General Bullet Physics Support and Feedback
Topic: How do you use Ghost Objects?
Replies: 25
Views: 17384

Re: How do you use Ghost Objects?

Hello, Yes, that`s it, but in my specific case, our ghost object collision flag is set to CF_NO_CONTACT_RESPONSE because we only want to use the ghost object as a wheel sensor to detect the wheel contacts with static(concave or convex) or dynamic objects. So in this perspective, the collision filter...
by rrck
Sat Nov 21, 2009 7:30 pm
Forum: General Bullet Physics Support and Feedback
Topic: Joint and Contact points Feedback
Replies: 9
Views: 2802

Re: Joint and Contact points Feedback

As for joints, as I understand joints are inherited from btTypedConstraint, which also have m_appliedImpulse member. Does this mean i can implement a callback for when a specified force has been breached in the constraint? This will be useful e.g. for decoupling trains, ripping off car doors, rippi...
by rrck
Sat Nov 21, 2009 1:23 pm
Forum: General Bullet Physics Support and Feedback
Topic: Joint and Contact points Feedback
Replies: 9
Views: 2802

Re: Joint and Contact points Feedback

You can get collision shape from body. getCollisionShape() or getRootCollisionShape(). Also manifold point have members partId and indexId. indexId store triangle id if it was collision with trimesh. partId contains index of shape if collision was with compoundShape (If I correctly understand when w...
by rrck
Sat Nov 21, 2009 10:37 am
Forum: General Bullet Physics Support and Feedback
Topic: How do you use Ghost Objects?
Replies: 25
Views: 17384

Re: How do you use Ghost Objects?

If I correctly understand the problem is that ghost objects are not colliding with static objects? (Sorry maybe I not correctly understand the problem.) May be reason is that with default collision filter static objects don't collide with other static objects? As I understand btCollisionObject(and b...
by rrck
Fri Nov 20, 2009 7:24 pm
Forum: General Bullet Physics Support and Feedback
Topic: Joint and Contact points Feedback
Replies: 9
Views: 2802

Re: Joint and Contact points Feedback

For contacts force: http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=4136&start=0 As for joints, as I understand joints are inherited from btTypedConstraint, which also have m_appliedImpulse member. EDIT: By joints I mean constraints. As I understand joints in ODE are constraints in Bullet.
by rrck
Sat Nov 14, 2009 1:24 pm
Forum: General Bullet Physics Support and Feedback
Topic: btRigidBody angular factor
Replies: 3
Views: 1394

Re: btRigidBody angular factor

As far as I can tell is that this is simply checking to make sure that the angular factor is not a null pointer before continuing. But m_angularFactor is btVector3 (in previous Bullet versions it was btSalar) and not pointer. If I properly understand angular factor purpose, maybe code should be som...
by rrck
Mon Nov 02, 2009 8:25 pm
Forum: General Bullet Physics Support and Feedback
Topic: btRigidBody angular factor
Replies: 3
Views: 1394

btRigidBody angular factor

Hello, I noticed some code in btRigidBody, which I can't understand. In applyImpulse() functions there is such code: if (m_angularFactor){...} After last rbtRigidBody changes m_angularFactor become btVector3. I debug that code and it seems that btScalar*() operator is called in that if. Is that supp...
by rrck
Tue Oct 13, 2009 4:33 pm
Forum: General Bullet Physics Support and Feedback
Topic: btRaycastVehicle wheel engine force
Replies: 0
Views: 697

btRaycastVehicle wheel engine force

Hello. I was looking through raycast vehicle code and noticed that when wheel engine force != 0, and wheel is not sliding, forward impulse applied from that wheel to chassis is engineForce * timestep. Shouldn't impulse dependent from wheel radius, like impulse = (engineForce / wheelRadius) * timeSte...