Search found 31 matches

by zarlox
Wed Aug 08, 2012 6:26 pm
Forum: General Bullet Physics Support and Feedback
Topic: Confused on how to set up a simple dynamics world
Replies: 4
Views: 3182

Re: Confused on how to set up a simple dynamics world

I see that you have commented out the activation state setting on the ball. Did you try it with disabling deactivation?

Code: Select all

_sphereBody->setActivationState(DISABLE_DEACTIVATION);
Because the sphere freezing might just be the rigid body deactivating
by zarlox
Thu Aug 02, 2012 9:37 pm
Forum: General Bullet Physics Support and Feedback
Topic: btContinuousDynamicsWorld disappeared
Replies: 2
Views: 1779

Re: btContinuousDynamicsWorld disappeared

Yes i think the btContinuousDynamicsWorld was removed. Now the proper way to deal with fast moving object is to use CCD (Continuous Collision Detection) on those objects. You use this with the normal btDiscreteDynamicsWorld. http://bulletphysics.org/mediawiki-1.5.8/index.php/Anti_tunneling_by_Motion...
by zarlox
Thu Aug 02, 2012 7:06 pm
Forum: General Bullet Physics Support and Feedback
Topic: Bodies inside other bodies.
Replies: 2
Views: 1493

Re: Bodies inside other bodies.

Well, bullet usually push back when a body get inside another one a little bit as part of its solver but this is really meant for bodies that were initially apart and got intersected via forces and collisions. I do not think bullet was meant to handle bodies that were initially added intersecting ea...
by zarlox
Thu Aug 02, 2012 7:01 pm
Forum: General Bullet Physics Support and Feedback
Topic: possible to make a "one way" wall...
Replies: 2
Views: 2001

Re: possible to make a "one way" wall...

One possible way of doing this would be to use a collision callback. Inside the callback, you check your dynamic body and see which side of the object is he coming from (looking at velocity direction). Depending on the direction, you cancel the collision or you let it collide. There might be better ...
by zarlox
Thu Oct 27, 2011 6:45 pm
Forum: General Bullet Physics Support and Feedback
Topic: btTriangleMeshShape to btTriangleShape (InternalEdges prob)
Replies: 10
Views: 4414

Re: btTriangleMeshShape to btTriangleShape (InternalEdges pr

Sorry i misunderstood the question. I'm affraid i do not know much on that side either :?
by zarlox
Thu Oct 27, 2011 3:05 pm
Forum: General Bullet Physics Support and Feedback
Topic: setLinearVelocity
Replies: 2
Views: 9471

Re: setLinearVelocity

Hi, I'm putting more checks in my code, and wanted to know the effect on a btRigidBody that has its CF_KINEMATIC_OBJECT or CF_STATIC_OBJECT flag raised? Should I be not allowing a call to setLinearVelocity on rigidBodies that have those flags set? Does linearvelocity, mass, inertialtensors, and all...
by zarlox
Thu Oct 27, 2011 3:00 pm
Forum: General Bullet Physics Support and Feedback
Topic: btTriangleMeshShape to btTriangleShape (InternalEdges prob)
Replies: 10
Views: 4414

Re: btTriangleMeshShape to btTriangleShape (InternalEdges pr

Or in other words: How do I fix the internal edge problem if I only have a btBvhTriangleMeshShape (which is concave). Well, as a matter of fact, btBvhTriangleMeshShape is the shape that you need to pass to the internal edge utility function. So i do not understand why you think you can't. Look at t...
by zarlox
Mon Oct 17, 2011 10:00 pm
Forum: General Bullet Physics Support and Feedback
Topic: Character on steep hills
Replies: 4
Views: 2339

Re: Character on steep hills

Maybe i am totally off, but maybe you are propulsing your character via impulse/force which vector do not take account of the Y (UP) element? So moving the character in zigzag would have less slope so the straight force vector (forward,side without up element) would have less resistance (dot product...
by zarlox
Mon Oct 17, 2011 9:29 pm
Forum: General Bullet Physics Support and Feedback
Topic: Player bounce when walking on flat surface
Replies: 6
Views: 2976

Re: Player bounce when walking on flat surface

Of course, you always should use with better fit your needs :) In my project, i first used the btHeightfieldTerrainShape. It is quite easy to setup from a height array and is fast. However i had those internal edge contact normal issues and to fix them using the current btInternalEdgeUtility, the ut...
by zarlox
Mon Oct 17, 2011 2:21 pm
Forum: General Bullet Physics Support and Feedback
Topic: Player bounce when walking on flat surface
Replies: 6
Views: 2976

Re: Player bounce when walking on flat surface

Maybe I'm a bit pedantic but I'd also consider the chance to get the rid of the triangle mesh and try simple collision shapes. Well, as long as you want a flat terrain, you can swap your triangle mesh with a plane shape. this will fix the internal edge collision. But if you want to shape your terra...
by zarlox
Fri Oct 14, 2011 7:02 pm
Forum: General Bullet Physics Support and Feedback
Topic: btBvhTriangleMeshShape problem
Replies: 2
Views: 1445

Re: btBvhTriangleMeshShape problem

This is due to the contact response on internal edges. The solution has been posted many time. Check this thread and implement the solution exactly as Argez showed. This should fix your cylinder jumpiness. http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=6662&p=24566&hilit=internal+edge#p2...
by zarlox
Fri Oct 14, 2011 6:47 pm
Forum: General Bullet Physics Support and Feedback
Topic: Fixed Point implementation
Replies: 4
Views: 2003

Re: Fixed Point implementation

I think he means using integer instead of float or double for the btScalar data type.

As far as i know, you can not. You can only choose single or double precision floating point.
by zarlox
Fri Oct 07, 2011 9:09 pm
Forum: General Bullet Physics Support and Feedback
Topic: Mesh as collision detector but not physical object
Replies: 18
Views: 10394

Re: Mesh as collision detector but not physical object

One thing you could do is use the dynamic body AABB (or better, OBB) and see if it intersect with the water volume AABB/OBB. You would have to do that test on your frame update. Hi, dude, I would like to know more about this point, could you tell me some more or is it convenient to paste some code ...
by zarlox
Fri Oct 07, 2011 8:15 pm
Forum: General Bullet Physics Support and Feedback
Topic: Mesh as collision detector but not physical object
Replies: 18
Views: 10394

Re: Mesh as collision detector but not physical object

I've created a ghostobject and tried that but didn't have any success. This is could be caused by me doing something wrong. So I was trying the other solution described above. I'm thinking that it would be more easier to simply check if an body is inside the water body. Then I don't have to care if...
by zarlox
Wed Sep 07, 2011 1:15 pm
Forum: General Bullet Physics Support and Feedback
Topic: contactTest thread-safety?
Replies: 0
Views: 2007

contactTest thread-safety?

Does anyone know if it is safe to do multiple btCollisionWorld::contactTest() from multiple threads?