Search found 456 matches

by Flix
Fri Dec 12, 2014 11:44 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Simple and Efficient Approximate Convex Decomposition
Replies: 41
Views: 46482

Re: Simple and Efficient Approximate Convex Decomposition

@khaled Just three quick questions: 1) Are you going to explain the meaning of the V-HACD2 params in your blog ? 2) I might be wrong, but in my early tests on the old V-HACD library, it seemed to me that it returned concave shards (i.e. verts and inds of concave solids: even if of course I could si...
by Flix
Mon Dec 08, 2014 10:05 am
Forum: General Bullet Physics Support and Feedback
Topic: btHeightfieldTerrainShape : item collides but falls through
Replies: 11
Views: 10658

Re: btHeightfieldTerrainShape : item collides but falls thro

I've not tried the fix proposed by lunkhound yet, but it looks interesting and I guess it could be useful for fixing problems with small bodies (such as parts of convex-decomposed shapes) getting stuck under the ground (when the ground mesh has a proper winding). Thanks for sharing it :D There are s...
by Flix
Thu Dec 04, 2014 9:49 am
Forum: General Bullet Physics Support and Feedback
Topic: RigidBodys remain asleep when ground static body is removed
Replies: 9
Views: 4695

Re: RigidBodys remain asleep when ground static body is remo

Slight0 wrote:Is this something I'm supposed to handle explicitly?
In short, yes.
by Flix
Tue Nov 25, 2014 4:16 pm
Forum: General Bullet Physics Support and Feedback
Topic: Softbody collision problem
Replies: 1
Views: 1648

Re: Softbody collision problem

No wonder! It's always been like that :) And that's one of the two reasons why I've stopped using soft bodies some year ago (the other reason is that soft bodies never go to sleep). P.S. Some user might argue that there could be other ways to check for collisions between rigid bodies and soft bodies...
by Flix
Thu Nov 20, 2014 9:05 am
Forum: General Bullet Physics Support and Feedback
Topic: Joint constraint friction
Replies: 11
Views: 6206

Re: Joint constraint friction

I don't know if this is appropriate or not, but there's an old thread about something similiar that could be helpful: http://www.bulletphysics.org/Bullet/php ... otor+force.
by Flix
Wed Nov 19, 2014 9:42 am
Forum: General Bullet Physics Support and Feedback
Topic: Volume of btConvexHullShape
Replies: 2
Views: 2127

Re: Volume of btConvexHullShape

I'm probably not enough "geometry-expert" to answer this. Anyways: What I'd do: 1) using btConvexHullComputer to compute vertices/triangle indices from the btConvexHullShape (*). 2) after that, you can use for example Stan Melax's code here http://www.melax.com/volint (I'm not sure, but I AFAIR it s...
by Flix
Wed Nov 19, 2014 9:19 am
Forum: General Bullet Physics Support and Feedback
Topic: Trying to bounce a box with a plane using DirectX 11.1
Replies: 2
Views: 2004

Re: Trying to bounce a box with a plane using DirectX 11.1

I'm trying to simulate a box that bounces with a plane and I'm beginner with bullet physics. I created a plane (box) and and a box that is falling Ok, you got a box and a plane. The problem is the ball is stalled while colliding with the plane I suppose you mean, the box is stalled... Here is my co...
by Flix
Tue Nov 18, 2014 12:20 pm
Forum: General Bullet Physics Support and Feedback
Topic: DebugDraw - no cylinders drawn for raycast vehicle's wheels?
Replies: 3
Views: 2498

Re: DebugDraw - no cylinders drawn for raycast vehicle's whe

Because that isn't something Bullet does by default. If you look at the Bullet VehicleDemo, in VehicleDemo::renderme(): void VehicleDemo::renderme() { updateCamera(); btScalar m[16];int i; btVector3 wheelColor(1,0,0); btVector3 worldBoundsMin,worldBoundsMax; getDynamicsWorld()->getBroadphase()->getB...
by Flix
Wed Nov 12, 2014 10:17 am
Forum: General Bullet Physics Support and Feedback
Topic: How to access a triangle from a GImpactMeshShape?
Replies: 6
Views: 4595

Re: How to access a triangle from a GImpactMeshShape?

Now I just have to figure out how to use the index with the mesh interface... In HitTriangleDemo.cpp (from the link I posted above), the relevant code is present in the last method HitTriangleDemo::process_triangle(...) (takes a hitTriangleIndex, a collision shape that can be GImpactMeshShape or bt...
by Flix
Tue Nov 11, 2014 2:18 pm
Forum: General Bullet Physics Support and Feedback
Topic: How to access a triangle from a GImpactMeshShape?
Replies: 6
Views: 4595

Re: How to access a triangle from a GImpactMeshShape?

Actually I think you should'n call shape->getBulletTriangle(index, triangle); in the first place. I think you should handle GImpactMeshShapes simply like btBvhTriangleMeshShapes: you must still have the (persistent) btStridingMeshInterface (or derived class) you have used to create the shape: it's t...
by Flix
Fri Oct 31, 2014 10:43 am
Forum: General Bullet Physics Support and Feedback
Topic: How to access a triangle from a GImpactMeshShape?
Replies: 6
Views: 4595

Re: How to access a triangle from a GImpactMeshShape?

I don't have an explicit answer to your question right now (I've not been using GImpactMeshShapes for a while :( ). However I just wanted to say that I remember a (very old) demo with source code that detected the hit triangle of a GImpactMeshShape. It's still here: http://www.bulletphysics.org/Bull...
by Flix
Tue Oct 14, 2014 11:12 am
Forum: General Bullet Physics Support and Feedback
Topic: [Solved] Softbody mesh has seams
Replies: 4
Views: 4377

Re: Softbody mesh has seams

I was hoping for some setting in the api which helps with this issue. Well unluckily there's no universal way to define a "graphic mesh". These's a more universal way to define a "physic mesh" (= vertices + (triangle) indices). What I mean is that any graphic engine/program can define vertices and ...
by Flix
Mon Oct 13, 2014 8:50 am
Forum: General Bullet Physics Support and Feedback
Topic: [Solved] Softbody mesh has seams
Replies: 4
Views: 4377

Re: Softbody mesh has seams

It's been a long time since I last used btSoftBodies... (BTW: I stopped using them mainly because they don't seem to go to sleep AFAIK, and collisions are not reported through the normal collision manifold processing (still AFAIR)). I haven't read a single line of the code you posted (lazy me :oops:...
by Flix
Fri Sep 26, 2014 11:29 am
Forum: General Bullet Physics Support and Feedback
Topic: sailplane RigidBody wheel - constraint setup
Replies: 10
Views: 6381

Re: sailplane RigidBody wheel - constraint setup

Now, I'am trying to add RigidBody wheels connected to main body using constraints. Like here: http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=17&t=4660. As far as I can remember about that link (not much to tell the truth :oops:), the constraint I used (I don't remember the type right no...
by Flix
Thu Sep 18, 2014 7:28 am
Forum: General Bullet Physics Support and Feedback
Topic: Change Height/Radius of Capsule Object when Loaded in world?
Replies: 2
Views: 2102

Re: Change Height/Radius of Capsule Object when Loaded in wo

Never tried, but I'd try the following steps: 1) remove the rigid body/collision object from the world 2) shape->setLocalScaling(btVector3(myScaling));// remember that capsule can be scaled in 2 dimensions only (e.g. btVector3(1.2,4.0,1.2) for Y capsule) 3) readd the rigid body/collision object to t...