Search found 16 matches

by Antonz
Thu Jan 16, 2014 8:28 am
Forum: General Bullet Physics Support and Feedback
Topic: btSliderConstraint
Replies: 9
Views: 3017

Re: btSliderConstraint

Can you answer a few questions about Bullet 3 plans, please (or maybe better to create separate topic?). I want to contribute from time to time and already submitted few minor patches but don't have much experience in advanced physics simulation topics, but can do some optimizations or fixes. For ex...
by Antonz
Wed Jan 15, 2014 11:30 am
Forum: General Bullet Physics Support and Feedback
Topic: btSliderConstraint
Replies: 9
Views: 3017

Re: btSliderConstraint

I'm also wanted to integrate Slider constraint because currently I'm using Generic 6DOF Constraint in a mode with one linear limit constrained and other 5 limits are locked. And it looks that G6DOF constrain has some quirks/bugs that are hard to describe/test : it's like a dead zone where constraint...
by Antonz
Wed Jan 15, 2014 11:03 am
Forum: General Bullet Physics Support and Feedback
Topic: How to copy btTypedConstraint ?
Replies: 1
Views: 1057

Re: How to copy btTypedConstraint ?

Of course you should not be able to copy such complex object because it's assigned in btDiscreteWorld and also binds one or two btRigidBody'es, has internal runtime state etc... so allowing copying semantic for them will be dangerous. That's why copy constructor and assignment operators are disabled...
by Antonz
Tue Dec 17, 2013 9:27 am
Forum: General Bullet Physics Support and Feedback
Topic: bind ghostObject to rigid body
Replies: 1
Views: 2040

Re: bind ghostObject to rigid body

greetings! is there a way to attach a ghost object to a rigid body? I'd like my game object to have a trigger zone around it. Should I simply change ghostobject's transform every tick? I have decided to abandon Ghost objects usage in our game, because I think that their design is all wrong - it's s...
by Antonz
Mon Oct 28, 2013 9:07 am
Forum: General Bullet Physics Support and Feedback
Topic: preparing for 2.82 release
Replies: 19
Views: 7948

Re: preparing for 2.82 release

What about Android? Forget about Android: Google and in particular Tim Murray (who is working on Renderscript at Google, and ex-NVIDIA employee from the CUDA team) is actively blocking OpenCL, because they try to push Renderscript, despite the fact that Qualcomm and ARM and other mobile driver deve...
by Antonz
Thu Oct 24, 2013 2:28 pm
Forum: General Bullet Physics Support and Feedback
Topic: preparing for 2.82 release
Replies: 19
Views: 7948

Re: preparing for 2.82 release

Cg is not generic enough to develop general purpose collision detection and constraint solver. You could use Cg for a simplified implementation. What do you mean by "architecture free"? OpenCL works on NVIDIA, AMD and Intel GPUs on all operating systems. What about Android? There is reports on Inte...
by Antonz
Tue Apr 03, 2012 9:16 am
Forum: Release Announcements
Topic: Bullet 2.80 SP1 release :OpenCL rigid bodies & Android
Replies: 17
Views: 121752

Re: Bullet 2.80 SP1 release :OpenCL rigid bodies & Android

Erwin, can you describe in details what Physics Effects are and also about Android/NEON optimization. My questions are: 1. What part of Bullet those "Physics Effects" library replaces or extends? 2. I can have NEON optimizations only with "Physics Effects"? I thought this is vector math optimization...
by Antonz
Mon Apr 02, 2012 10:07 am
Forum: General Bullet Physics Support and Feedback
Topic: MotionState Data Structure
Replies: 1
Views: 1194

Re: MotionState Data Structure

What are you really want to achieve? btMotionState is just a two-funcs interfaces: one for getting "user" matrix from user to physics (usually kinematic objects), and one for setting it from physics to user (dynamic objects). Obviously it's better to extend/wrap this class for additional functionali...
by Antonz
Mon Apr 02, 2012 9:59 am
Forum: General Bullet Physics Support and Feedback
Topic: Need help with bullet contact triggers
Replies: 8
Views: 3855

Re: Need help with bullet contact triggers

Just my 5 cents... Here's how I'm wrapping contact callbacks : http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?p=27489#p27489 I just don't like Singletons and try to avoid them if possible. Simple ones are problematic, and complex ones (like based on Loki Singleton) are also have their prob...
by Antonz
Wed Mar 28, 2012 1:01 pm
Forum: General Bullet Physics Support and Feedback
Topic: Collision Callbacks??
Replies: 2
Views: 1739

Re: Collision Callbacks??

Are Ghost objects really useful for implementing things like triggers? They needs to be polled for changes and it will be a lot of overhead. Also I don't like them because it's a separate type of object, it's not static object, not kinematic, not dynamic, but "ghost" object, phew. So I cannot really...
by Antonz
Wed Mar 28, 2012 11:11 am
Forum: General Bullet Physics Support and Feedback
Topic: CCD / motion clamping values
Replies: 0
Views: 1277

CCD / motion clamping values

Hi. What are the best values for "CCD Motion threshold" and "Swept sphere radius" if my moving object is a ball? As I understood swept sphere radius should be contained within rigid body, so for my case it should be a bit smaller than actual ball radius. But how much smaller? Is 1-2% smaller than ac...
by Antonz
Mon Dec 13, 2010 6:04 pm
Forum: General Bullet Physics Support and Feedback
Topic: Triggers and contact breaking.
Replies: 0
Views: 878

Triggers and contact breaking.

Hi. I want to use a convex collision object with and check for touch events with particular type of objects (with a given mask). I found it convenient to use global callbacks gContactAddedCallback and gContactDestroyedCallback . So, this trigger has btCollisionObject::CF_CUSTOM_MATERIAL_CALLBACK set...
by Antonz
Sat Nov 20, 2010 12:04 pm
Forum: General Bullet Physics Support and Feedback
Topic: Newbie help: CCD and tunneling
Replies: 5
Views: 2677

Re: Newbie help: CCD and tunneling

Is there an example with moving/rotating kinematic/ghost object pushing a rigid body using forces when they collide?
by Antonz
Sat Nov 20, 2010 11:57 am
Forum: General Bullet Physics Support and Feedback
Topic: Newbie help: CCD and tunneling
Replies: 5
Views: 2677

Re: Newbie help: CCD and tunneling

Looked into CCD code of Bullet. OK, so CCD is working for ball when it's moving fast and collides with static geometry or non-moving flipper. But obviously it's not working for kinematic rotating flipper (no movement, and also sphere shape used for CCD will not help here). Seems that I can do a conv...