Search found 145 matches

by AlexSilverman
Wed Nov 04, 2009 7:07 pm
Forum: General Bullet Physics Support and Feedback
Topic: Collision callbacks questions
Replies: 28
Views: 41782

Re: Collision callbacks questions

Such callbacks might not even be available, especially when the collision detection happens on SPU (PlayStation 3) or GPU (upcoming OpenCL version of Bullet 3.x). Not to take this thread too far off topic, but is that to say that the function won't get called, or simply that the function won't be a...
by AlexSilverman
Wed Nov 04, 2009 4:18 pm
Forum: General Bullet Physics Support and Feedback
Topic: Collision callbacks questions
Replies: 28
Views: 41782

Re: Collision callbacks questions

It seems to me that overriding the broad/nearphase functions would result in lots of false positives. Did you perhaps mean registering a ContactAddedCallback? That will get fired for every collision (as you mentioned) but not for every potential collision, as would be the case with the broad/nearpha...
by AlexSilverman
Tue Nov 03, 2009 6:00 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: How to access Wii and Xbox360
Replies: 2
Views: 3738

Re: How to access Wii and Xbox360

As far as I know, there is no Wii/360 version, as there is a PS3 version. Integration with the Wii is exceedingly simple, and I'd be surprised if it's any more difficult to get it running on the 360.

- Alex
by AlexSilverman
Tue Sep 15, 2009 1:53 pm
Forum: General Bullet Physics Support and Feedback
Topic: BVH question
Replies: 6
Views: 3538

Re: BVH question

I talked with the guy experiencing this problem about the makeup of the scene and it turns out he was manually holding several boxes in positions where they were penetrating the wall mesh, thus the slowdown and resulting fix when the wall was enlarged. Sorry for the misdirection, but thanks for the ...
by AlexSilverman
Sat Sep 05, 2009 2:09 am
Forum: General Bullet Physics Support and Feedback
Topic: BVH question
Replies: 6
Views: 3538

Re: BVH question

I didn't profile it at the time, as we ended up removing most of the unnecessary triangles (and there were quite a few :) ) from the mesh to save the framerate as quickly as possible. My guess is that they were about 10 meters away. Well outside the AABB of the wall, and the objects themselves were ...
by AlexSilverman
Fri Sep 04, 2009 10:11 pm
Forum: General Bullet Physics Support and Feedback
Topic: BVH question
Replies: 6
Views: 3538

Re: BVH question

sparkprime,

The slowdown was as soon as other objects were added to the scene, not just when collisions happened.
by AlexSilverman
Fri Sep 04, 2009 4:37 pm
Forum: General Bullet Physics Support and Feedback
Topic: BVH question
Replies: 6
Views: 3538

BVH question

Hello, I'm not sure if this is a BVH question in general or something specific to Bullets use of them, but here goes. We have a wall with some holes in it and we're using a btBvhTriangleMeshShape to represent it. It's about 9x18x4 (all meters), so it isn't all that large. We added some more detail t...
by AlexSilverman
Thu Jul 30, 2009 1:46 pm
Forum: General Bullet Physics Support and Feedback
Topic: Locking a dynamic object in place.
Replies: 10
Views: 4789

Re: Locking a dynamic object in place.

What's worked for me in the past is removing the body before changing anything, then adding it afterwards.

Code: Select all

    _pSimulationWorld->removeRigidBody(obj->GetBody());
    obj->GetBody()->setMassProps(0, btVector3(0,0,0));
    _pSimulationWorld->addRigidBody(obj->GetBody());
- Alex
by AlexSilverman
Tue Jul 28, 2009 3:03 pm
Forum: General Bullet Physics Support and Feedback
Topic: Correct way to move objects around in game
Replies: 7
Views: 6579

Re: Correct way to move objects around in game

Will this still produce an event so I can use a callback or trigger to do what I am looking for? Static -> static collision is ruled out by the broadphase collision filter I believe. I'm not positive about all of the reprecussions of this, but you could probably explicitly set the collision filters...
by AlexSilverman
Thu Jul 16, 2009 7:59 pm
Forum: General Bullet Physics Support and Feedback
Topic: RigidBody settings for golf ball style bouncing
Replies: 6
Views: 5643

Re: RigidBody settings for golf ball style bouncing

You could override the contact manifold collision normal by writing your own ContactAddedCallback and setting gContactAddedCallback to point to it. There's an example of this in the Multimaterial demo (and several others, but I can't remember which offhand so search for "gContactAddedCallback&q...
by AlexSilverman
Thu Jul 02, 2009 3:02 pm
Forum: General Bullet Physics Support and Feedback
Topic: Building the bullet libraries with codewarrior for Wii
Replies: 2
Views: 1828

Re: Building the bullet libraries with codewarrior for Wii

Building Bullet for the Wii has been very simple in my experience. I haven't used any automatic project generation, but you'll need to make slight changes to the library (mostly around the timers/profiling if I remember correctly) so it probably won't be a 100% hands off experience anyway. I just ma...
by AlexSilverman
Wed May 20, 2009 9:36 pm
Forum: General Bullet Physics Support and Feedback
Topic: KinimaticController can push RigidBody into static Object
Replies: 1
Views: 2215

Re: KinimaticController can push RigidBody into static Object

While the behavior you're seeing might not be desired, it's not technically wrong. A Kinematic object is a type of static object, and it will not get pushed around by any dynamic objects, so the dynamic boxes in your scene will respond no matter how far into the wall. We used a sphere for our charac...
by AlexSilverman
Thu Mar 19, 2009 7:34 pm
Forum: General Bullet Physics Support and Feedback
Topic: Bullet logo?
Replies: 5
Views: 3703

Re: Bullet logo?

Can't you just convert the pdf to whatever resolution you want? It's vector so there should be no quality concerns.

- Alex
by AlexSilverman
Mon Mar 16, 2009 2:47 pm
Forum: General Bullet Physics Support and Feedback
Topic: Callback & btMotionState performance [Known Issue]
Replies: 6
Views: 3510

Re: Callback & btMotionState

As I understand it, there is currently no callback for when objects have moved since the last frame. btMotionState::setWorldTransform() is currently called fairly often (once per frame per body per simulation substep, plus once more per frame per body after all simulation has been done). Note that t...
by AlexSilverman
Tue Mar 10, 2009 8:53 pm
Forum: Non-technical forum and license/patent discussion
Topic: Another license question
Replies: 4
Views: 10338

Re: Another license question

Contributions to Bullet are very welcome, but before accepting contributions we do some basic review to make sure it doesn't obviously violate patents. Glad to hear there's some oversight beyond what I think is all right :) Do you have any idea what authoring tools to use for shattering/fracture? I...