Search found 456 matches

by Flix
Wed Dec 14, 2016 11:22 am
Forum: General Bullet Physics Support and Feedback
Topic: [SOLVED]Beginner Q re parameters to setMotorTarget()
Replies: 2
Views: 1360

Re: Beginner Q re parameters to setMotorTarget()

AFAIR (from some year ago... :? ): My question is: if the motor's velocity is getting set to the total distance per delta time... Nope, the motor's target velocity is getting set. Bullet does not set it instantly, but sets some force that is based on the MaxMotorForce every timestep to try to get to...
by Flix
Mon Nov 07, 2016 12:08 pm
Forum: General Bullet Physics Support and Feedback
Topic: Using broadphase collision detection only
Replies: 8
Views: 3212

Re: Using broadphase collision detection only

Specifically, I want a fast way to: 1. determine which objects are in my view volume (so I can render only these objects) 2. determine which objects are inside of a light volume (so I can use just these objects for shadow calculations) My thinking is to use Bullet's broadphase algorithms for this T...
by Flix
Wed Jun 22, 2016 12:51 pm
Forum: General Bullet Physics Support and Feedback
Topic: Incorrect collision normal in sphere/triangle mesh collision
Replies: 5
Views: 3438

Re: Incorrect collision normal in sphere/triangle mesh colli

Thanks for taking the time to test the btMultisphereShape too :) . P.S. To make your patch depend on Bullet Collisions only, btCollisionObject.h should have a isStaticOrKinematicObject() method that just depends on its own collision flags. It could be used instead of checking the mass (and should be...
by Flix
Tue Jun 21, 2016 12:05 pm
Forum: General Bullet Physics Support and Feedback
Topic: Incorrect collision normal in sphere/triangle mesh collision
Replies: 5
Views: 3438

Re: Incorrect collision normal in sphere/triangle mesh colli

It's basically the same patch applied at two locations (once for sphere triangle collision, the other for convex vs triangle). Then I guess it affects spheres made with one btMultiSphereShape too, isn't t? In any case I think it's better if you post a issue to the bullet3 issue section ( https://gi...
by Flix
Mon May 30, 2016 12:27 pm
Forum: General Bullet Physics Support and Feedback
Topic: Why is there no onCollision callback for collision shapes?
Replies: 2
Views: 1220

Re: Why is there no onCollision callback for collision shape

I had made (5 year ago) a demo on how to easily do that without modifying the Bullet source code. However, it's 5 years old... and worked with the old libBulletOpenGL. Maybe you can still reuse most of the files in it... I posted the demo here (see last post): http://www.bulletphysics.org/Bullet/php...
by Flix
Sat Apr 30, 2016 11:19 am
Forum: General Bullet Physics Support and Feedback
Topic: Debug Draw btCollisionObject
Replies: 1
Views: 1246

Re: Debug Draw btCollisionObject

btGImpactMeshShape* shape = static_cast<btGImpactMeshShape*>(co->getCollisionShape()); btStridingMeshInterface* mi = shape->>getMeshInterface(); // get vertices and indices from the btStridingMeshInterface (see: btStridingMeshInterface.h) The same is valid for btBvhTriangleMeshShapes. P.S. And, as ...
by Flix
Wed Apr 13, 2016 7:28 pm
Forum: General Bullet Physics Support and Feedback
Topic: Arbitrary Mesh - how to create collision shape?
Replies: 4
Views: 2156

Re: Arbitrary Mesh - how to create collision shape?

Yes, that demo has not been ported to the Bullet3 package... However, there's still a libConvexDecomposition (that is built by default and it's based on John Ratcliff's work) and there are still the two files: btGImpactConvexDecompositionShape.h btGImpactConvexDecompositionShape.cpp: AFAIR they were...
by Flix
Wed Apr 13, 2016 11:28 am
Forum: General Bullet Physics Support and Feedback
Topic: Arbitrary Mesh - how to create collision shape?
Replies: 4
Views: 2156

Re: Arbitrary Mesh - how to create collision shape?

1) btGImpactShape 2) Convex decomposition: decompose the mesh into convex child shapes of a btCompoundShape (or of a btGImpactConvexDecompositionShape that's probably deprecated...). Known algorithms: -> V-HACD: https://github.com/kmammou/v-hacd (good for closed (=waterproof) meshes) -> includes a B...
by Flix
Mon Apr 11, 2016 12:21 pm
Forum: General Bullet Physics Support and Feedback
Topic: How to volume/thick ray test? ,ClosestRayResultCallback?
Replies: 2
Views: 1640

Re: How to volume/thick ray test? ,ClosestRayResultCallback?

hyyou wrote:Bullet has point ray test functions :-
Code:
btCollisionWorld::ClosestRayResultCallback RayCallback(Start, End);

But in a situation where a bazooka shoot a very fast big rocket (e.g. rigidBody), does BulletPhysic has any function to ray test that volume?
A convex cast instead of a ray cast ?
by Flix
Thu Mar 24, 2016 2:35 pm
Forum: General Bullet Physics Support and Feedback
Topic: Scan area for intersecting shapes.
Replies: 8
Views: 2316

Re: Scan area for intersecting shapes.

It is pity that Bullet don't have AABB query like Box2D. I haven't read the whole series of posts, but maybe you can try: btDbvtBroadphase::aabbTest (const btVector3 &aabbMin, const btVector3 &aabbMax, btBroadphaseAabbCallback &callback) P.S. I have never tried it and I don't know if it works and/o...
by Flix
Wed Mar 16, 2016 4:53 pm
Forum: General Bullet Physics Support and Feedback
Topic: Get vertex of btGImpactMeshShape
Replies: 2
Views: 1702

Re: Get vertex of btGImpactMeshShape

As usual, another already-answered question:

http://bulletphysics.org/Bullet/phpBB3/ ... ace#p34363

P.S. Maybe we should ask users to use the "Search" button before posting.
by Flix
Thu Feb 25, 2016 9:39 am
Forum: General Bullet Physics Support and Feedback
Topic: Is rayTest thread safe?
Replies: 9
Views: 3041

Re: Is rayTest thread safe?

Is rayTest thread safe? I've never tried, but, according to: http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=10232&start=30&hilit=ray , to make it thread safe some changes must be applied. Probably these changes (but I don't know if these are the ONLY changes required): https://github.co...
by Flix
Wed Feb 03, 2016 12:40 pm
Forum: General Bullet Physics Support and Feedback
Topic: Slider properties
Replies: 15
Views: 4569

Re: Slider properties

One more stupid question is is it possible to switch a body from dynamic to static? Or do you need to destroy and recreate it? It's probably better to remove it from the world and reinsert it after modifying all the required flags. I don't remember exactly how to do it, however it should be possibl...
by Flix
Tue Feb 02, 2016 12:51 pm
Forum: General Bullet Physics Support and Feedback
Topic: Slider properties
Replies: 15
Views: 4569

Re: Slider properties

Okay sorry so I'm a little confused. Is there specifically a state you can set to cause the object to be static? I think we are just setting an infinite mass, so does the object still count as dynamic even though it is an infinite mass, or is it now implicitly static? In Bullet rigid bodies can be ...
by Flix
Mon Feb 01, 2016 7:37 pm
Forum: General Bullet Physics Support and Feedback
Topic: Slider properties
Replies: 15
Views: 4569

Re: Slider properties

Well, I guess it's not a mass-difference problem: it's just that a static object is probably not considered simply as an infinite mass body, but Bullet has some "specialized way" to treat it (actually I'm just guessing: I should see the code to tell it :) ). For sure the inertia of static bodies is ...