Search found 456 matches

by Flix
Thu Apr 16, 2015 8:37 am
Forum: General Bullet Physics Support and Feedback
Topic: can constraint motors affect only one rigid body?
Replies: 3
Views: 2530

Re: can constraint motors affect only one rigid body?

This causes both the rigid bodies to rotate. Is there a way just to drive the second rigid body with the motor while remaining connected to the first? If the first object can't be static, then the only other solution I can think about is playing with the masses and/or local inertias of the two bodi...
by Flix
Thu Apr 16, 2015 8:31 am
Forum: General Bullet Physics Support and Feedback
Topic: btCompoundShape: collision detection problem! :?:
Replies: 10
Views: 4387

Re: btCompoundShape: collision detection problem! :?:

It might be an "update AABB" problem. I'd try to solve the problem this way: By NOT using btCompoundShape for static objects in the first place. Just add the child shapes directly to the world as static btRigidBodies (or plain btCollisionObjects if you like). Some tests I made some time ago showed a...
by Flix
Sat Mar 28, 2015 7:33 am
Forum: Applications, Games, Demos or Movies using Bullet
Topic: appHACDDemo (and Convex Decomposition tool)
Replies: 21
Views: 39418

Re: appHACDDemo (and Convex Decomposition tool)

I saw this V-HACD and read how to include it [...] I'm using the last version 2 from github. Then you can't use appHACDDemo tool in the first place, because I wrote: First: this "Tool/Demo" is rather old and won't work with the current "git" version of VHACD-2: I've just added a note in the first p...
by Flix
Thu Mar 26, 2015 12:54 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: appHACDDemo (and Convex Decomposition tool)
Replies: 21
Views: 39418

Re: appHACDDemo (and Convex Decomposition tool)

I'm just a beginner, so this may seem a little stupid but I couldn't set up the load .bcs method. First: this "Tool/Demo" is rather old and won't work with the current "git" version of VHACD-2: I've just added a note in the first post. I suppose you use the plain HACD version. I imported the "btBul...
by Flix
Mon Mar 02, 2015 9:20 am
Forum: General Bullet Physics Support and Feedback
Topic: GhostObject collision with narrowphase instead of AABB?
Replies: 1
Views: 1993

Re: GhostObject collision with narrowphase instead of AABB?

First, sorry, I've just read the post title (= not its content). Second, this link is rather old, but it might still work (expecially the ghost object demo included in it): please tell me if it's useful for you or not: http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=6195&hilit=ghost+...
by Flix
Fri Feb 13, 2015 10:22 am
Forum: General Bullet Physics Support and Feedback
Topic: How to represent this arena in bullet?
Replies: 4
Views: 2904

Re: How to represent this arena in bullet?

The reason i believe trigngle mesh is expensive is that if i use it, the aabb of arena will intersect with every single aabb in this arena, bullet will test the arena with every dynamic rigid body in every step(i'm not 100% sure), the test includes every face in triangle mesh(i guess), that must be...
by Flix
Thu Feb 12, 2015 10:12 am
Forum: General Bullet Physics Support and Feedback
Topic: How to represent this arena in bullet?
Replies: 4
Views: 2904

Re: How to represent this arena in bullet?

I believe it's too expensive to use Triangle mesh. It that's a static wide geometry, I don't think it's too expensive at all: you can try and see :) . However I agree that usually convex hulls behave better that btBvhTriangleMeshes: in that case you can use vhacd, as suggested by drleviathan, or ju...
by Flix
Wed Jan 28, 2015 9:38 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Simple and Efficient Approximate Convex Decomposition
Replies: 41
Views: 46606

Re: Simple and Efficient Approximate Convex Decomposition

I've updated RBD's Blender addon to support VHACD version 2.2. Here it is: object_vhacd.py.zip P.S. My knowledge of python is minimal and I tested the plugin on Ubuntu only. Hope it works on other systems as well. P.S.2 There's a visual artifact in the GUI when loading presets: the GUI does not upda...
by Flix
Sat Jan 17, 2015 10:03 am
Forum: General Bullet Physics Support and Feedback
Topic: CPU multithreading is working!
Replies: 145
Views: 79882

Re: CPU multithreading is working!

About schedule(static, 50) : This is how OpenMP partitions the threads: 50 should mean that each thread takes 50 operations at a time. static means that the partition is made ahead of time (less time to partition, but some threads may end up early and have nothing left to do). Alternatives are dynam...
by Flix
Sat Jan 10, 2015 9:47 am
Forum: General Bullet Physics Support and Feedback
Topic: void casting parameters never used
Replies: 2
Views: 1970

Re: void casting parameters never used

Hehe :) ... Lines like that are commonly used in C++ to remove possible compilation warnings caused by the fact that a method parameter is never used inside the method's scope. I don't know if that's the case here: many times programmers start adding those lines, then they actually use those variabl...
by Flix
Thu Dec 18, 2014 9:21 am
Forum: General Bullet Physics Support and Feedback
Topic: CPU multithreading is working!
Replies: 145
Views: 79882

Re: CPU multithreading is working!

:D ! Just to say I'm very happy I can use callbacks and the OpenMP version! Only one additional thing: On Linux 64bit in LinearMath/btThreads.cpp , I had to change: bool btIsAligned( const void* ptr, unsigned int alignment ) { btAssert( ( alignment & ( alignment - 1 ) ) == 0 ); // alignment should b...
by Flix
Wed Dec 17, 2014 11:31 am
Forum: General Bullet Physics Support and Feedback
Topic: CPU multithreading is working!
Replies: 145
Views: 79882

Re: CPU multithreading is working!

I don't usually like to pop-in and interrupt an ongoing discussion: however I'd like to make a few brief questions/considerations, soon after having thanked lunkhound for having restored/rewritten/reconsidered/reforked the Bullet Multithreaded branch :) . Here are my questions/considerations (I stil...
by Flix
Tue Dec 16, 2014 12:00 pm
Forum: General Bullet Physics Support and Feedback
Topic: Compound Shape's children with different Friction ?
Replies: 1
Views: 1717

Re: Compound Shape's children with different Friction ?

Using a custom material callback you can override friction on a compound child basis. I don't remember the details ATM, but AFAIR the introduction of the btCollisionObjectWrapper class into Bullet was done to extend this possibility to handle nested compound children too. However I'd stick to the pa...
by Flix
Tue Dec 16, 2014 11:50 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Simple and Efficient Approximate Convex Decomposition
Replies: 41
Views: 46606

Re: Simple and Efficient Approximate Convex Decomposition

@RBD: Thanks for posting it :) ! P.S. On Linux 64bit and Blender 2.72b (and maybe on other POSIX systems), I had to change: vhacd_process = Popen(cmd_line, bufsize=-1) to vhacd_process = Popen(cmd_line, bufsize=-1, executable=None, stdin=None, stdout=None, stderr=None, preexec_fn=None, close_fds=Tr...