Search found 32 matches

by Dominik
Thu Dec 09, 2010 11:35 am
Forum: General Bullet Physics Support and Feedback
Topic: Why is my btTriangleMeshShape nonmoving?
Replies: 5
Views: 4692

Re: Why is my btTriangleMeshShape nonmoving?

Nope, static does not mean that it can't be moved, it only means that its dynamics cannot be simulated by the physicsworld. As far as I know, it should behave exactly the same way as other shapes if you use it solely for collision detection. Could you post some code where it fails? And did you try a...
by Dominik
Wed Dec 08, 2010 9:21 am
Forum: General Bullet Physics Support and Feedback
Topic: Why is my btTriangleMeshShape nonmoving?
Replies: 5
Views: 4692

Re: Why is my btTriangleMeshShape nonmoving?

Hi mObject->getCollisionShape()->getAabb()->(identity, min, max); This always returns the AABB of the collision shape only, (since you transform it by the identity). Keep in mind that a collision shap eis only the actual shape, without a 3D position/orientation. After all, one shape could be used by...
by Dominik
Wed Dec 08, 2010 8:25 am
Forum: General Bullet Physics Support and Feedback
Topic: Pendulum in vacuum
Replies: 4
Views: 6473

Re: Pendulum in vacuum

You move your dynamic object to the position (3,0,0), so the static object is left of the dynamic one. Howeveer, you then also set the constraint's pivot to (3,0,0), which is to the right of the dynamic one. Therefore, the constraint initially tries to restore a valid position, moving the constraint...
by Dominik
Fri Nov 19, 2010 3:56 pm
Forum: General Bullet Physics Support and Feedback
Topic: Quaternion strangeness
Replies: 2
Views: 2692

Re: Quaternion strangeness

btQuaternion.h, line 33

Code: Select all

btQuaternion(const btScalar& x, const btScalar& y, const btScalar& z, const btScalar& w)
Why do you think you should pass w first?
by Dominik
Mon Sep 20, 2010 7:48 am
Forum: General Bullet Physics Support and Feedback
Topic: Gravity 10 or 9.8? and weight calculations for dummies
Replies: 1
Views: 4364

Re: Gravity 10 or 9.8? and weight calculations for dummies

9.8 is pretty close to 10, so its just a rounded value. Why do you want to use 9.8? The normallly used standard value is 9.81, even more precise is the global average of 9.80665m/s^2. ANd even this varies depending on the location. So it's always just an estimate. if you want a more precise one - wh...
by Dominik
Thu Sep 09, 2010 8:10 am
Forum: General Bullet Physics Support and Feedback
Topic: DirectX9 and Bullet
Replies: 4
Views: 5510

Re: DirectX9 and Bullet

The problem is that you are mixing different of code generation settings. If you check MSVC in the project settings under C/C++>Code Generation>Runtime Library, you can set either Multithreaded/MultithreadedDebug, or MultithreadedDLL/MultithreadedDebugDLL. This setting has to be the same also for th...
by Dominik
Wed Aug 25, 2010 10:31 am
Forum: General Bullet Physics Support and Feedback
Topic: Re: Bullet performance on Android - Determinism problem
Replies: 11
Views: 10735

Re: Bullet performance on Android - Determinism problem

About the sleeping bodys - if you know that some bodies start in a position where they won't be moved by the simulation, so that they would be put to sleep soon, you might want to About the determinism: As far as I understand, both your examples of calling stepSimulation should be deterministic. A w...
by Dominik
Tue Aug 24, 2010 10:41 am
Forum: General Bullet Physics Support and Feedback
Topic: Re: Bullet performance on Android - Determinism problem
Replies: 11
Views: 10735

Re: Bullet performance on Android

The problem is that in the beginning, bullet simulates all the 150 boxes on the ground - which is pretty much for a small phone :P
After some time, bullet sees that the boxes on the floor don't move, and puts them to sleep, thus the performance increase
by Dominik
Tue Jun 15, 2010 11:46 am
Forum: General Bullet Physics Support and Feedback
Topic: Help: Ball floating ontop of and Maze
Replies: 4
Views: 4902

Re: Help: Ball floating ontop of and Maze

Is it possible that your mesh contains quadrilateral faces? If you interprete a quad-face array as triangles, weird stuff like on your screenshot can happen.
by Dominik
Tue Dec 01, 2009 12:15 pm
Forum: General Bullet Physics Support and Feedback
Topic: BUG Report:LINK2001 and BT_USE_DOUBLE_PRECISION
Replies: 1
Views: 3208

Re: BUG Report:LINK2001 and BT_USE_DOUBLE_PRECISION

Try linking against the double-precision bullet libraries in E:\dev\physics\bullet\2.75\out\debug_dbl8\libs instea of the libs in the dir you gave
However, I think they are build with Mtd instead of MDd as the libs in the *_dll8, so you may have to adjust this manually in the bullet projects
by Dominik
Sun Oct 04, 2009 4:36 pm
Forum: General Bullet Physics Support and Feedback
Topic: btMatrix3x3::setFromOpenGLSubMatrix transpose the matrix
Replies: 3
Views: 5642

Re: btMatrix3x3::setFromOpenGLSubMatrix transpose the matrix

sorry, mixed up row- and clumn-major... Still, its correct that opengl uses the "transposed" notation as seen from bullet (and most other toolkits) an OpenGL | a b c d | | e f g h | | i j k l| | m n o p | is stored as mat[16]={ a e i m b f j n c g k o d h l p } while most other use the row...
by Dominik
Thu Oct 01, 2009 9:10 am
Forum: General Bullet Physics Support and Feedback
Topic: results of rayTest vs Multiple Objects
Replies: 3
Views: 4671

Re: results of rayTest vs Multiple Objects

Bullet's ray test uses the btCollisionWorld::RayResultCallback, whose function addSingleResult is called for each found ray intersection. Sinply inherit this class, and add your own code to addSingleResult, where you check if the object's user pointer is non-NULL, and then store it somewhere (prefer...
by Dominik
Fri Jul 17, 2009 12:11 pm
Forum: General Bullet Physics Support and Feedback
Topic: Simplest possible C/D between two objects?
Replies: 7
Views: 6452

Re: Simplest possible C/D between two objects?

Thanks for pointing out the mem leak. Putting this at the end of the function should fix it... pAlgorithm->~btCollisionAlgorithm(); pBtWorld->getDispatcher()->freeCollisionAlgorithm( pAlgorithm ); pManifold should usually be non-NULL after the call (except, as it seems, for GIMPACT shape tests, wher...
by Dominik
Wed Jun 24, 2009 11:33 am
Forum: General Bullet Physics Support and Feedback
Topic: Hello World...
Replies: 6
Views: 53989

Re: Hello World...

if you use #include <*.h>, you do not use a library. In the header files, there are only declarations, while the libraries include the actual definitions (the stuff in the .cpp-files). So, you have to tell your application to use the bullet libraries (which is done during linking, when the compiler ...
by Dominik
Wed Jun 24, 2009 7:31 am
Forum: General Bullet Physics Support and Feedback
Topic: Hello World...
Replies: 6
Views: 53989

Re: Hello World...

btAxisSweep3(const btVector3& worldAabbMin,const btVector3& worldAabbMax, unsigned short int maxHandles = 16384, btOverlappingPairCache* pairCache = 0, bool disableRaycastAccelerator = false) The btAxisSweep3 construcot uses default arguments, so you don't have to specify the last ones. You...