Search found 32 matches

by topcomer
Fri Sep 28, 2007 9:36 pm
Forum: General Bullet Physics Support and Feedback
Topic: how to use gimpact trimesh-trimesh?
Replies: 14
Views: 12136

Re: how to use gimpact trimesh-trimesh?

I tried the callback: bool CustomMaterialCombinerCallback(btManifoldPoint& cp, const btCollisionObject* colObj0, int partId0, int index0, const btCollisionObject* colObj1, int partId1, int index1) { if( colObj0->isKinematicObject() ) std::cout << "*************TRIANGLE ID: " << index0 << std::endl; ...
by topcomer
Fri Sep 28, 2007 7:36 am
Forum: General Bullet Physics Support and Feedback
Topic: how to use gimpact trimesh-trimesh?
Replies: 14
Views: 12136

Re: how to use gimpact trimesh-trimesh?

Actually, it seems you are not just asking for more contact points, you want a mapping between vertices of the mesh, and contact points. When a concave trimesh versus trimesh is colliding/overlapping, ultimately this ends up in multiple triangle versus triangle tests. This gives one or more contact...
by topcomer
Thu Sep 27, 2007 3:12 pm
Forum: General Bullet Physics Support and Feedback
Topic: how to use gimpact trimesh-trimesh?
Replies: 14
Views: 12136

Re: how to use gimpact trimesh-trimesh?

GIMPACT 0.2 and GIMPACT 0.3 use the btPersistentManifold and btManifoldResult for reducing the number of collision contacts, so you'll get a very little number of contact points (no more than four). This kind of result is very useful for physics collisions But your request of more points its more a...
by topcomer
Thu Sep 27, 2007 6:46 am
Forum: General Bullet Physics Support and Feedback
Topic: how to use gimpact trimesh-trimesh?
Replies: 14
Views: 12136

Re: how to use gimpact trimesh-trimesh?

I've been using that code you posted for the last 4 days, but it seems that I get only 4 vertices, so I still have to iterate through all the triangles to see which are colliding. Also, the four points I get do not correspond to any vertex of my mesh, but they seem to just lay on the triangles surfa...
by topcomer
Wed Sep 26, 2007 5:10 pm
Forum: General Bullet Physics Support and Feedback
Topic: how to use gimpact trimesh-trimesh?
Replies: 14
Views: 12136

how to use gimpact trimesh-trimesh?

I'm using bullet and gimpact (as you can see in some other post) but I really don't understand how to use the informations provided by the contact manifold. If I get 4 collision points for each pair, then I have to make a search and several tests using normals and points-on-a-triangle checks to see ...
by topcomer
Wed Sep 26, 2007 9:14 am
Forum: General Bullet Physics Support and Feedback
Topic: gimpact and deformable meshes
Replies: 4
Views: 2470

Re: gimpact and deformable meshes

any hint? if I have to check all the collision points against all my triangles to find which are colliding it's pointless to use a fast collision detection..
by topcomer
Tue Sep 25, 2007 8:52 am
Forum: General Bullet Physics Support and Feedback
Topic: Concave trimesh contact points reduction
Replies: 5
Views: 5058

Re:

You can use multiple contact manifolds for concave versus concave: The optional GIMPACT integration in Bullet uses an array of contact manifolds. See MovingConcaveDemo, and Bullet/Extras\GIMPACTBullet\btConcaveConcaveCollisionAlgorithm.cpp One approach you can try is to cluster/group contact points...
by topcomer
Mon Sep 24, 2007 6:09 pm
Forum: General Bullet Physics Support and Feedback
Topic: gimpact and deformable meshes
Replies: 4
Views: 2470

Re: gimpact and deformable meshes

I have a problem in the contact between a kinematic trimesh and the static ground present in MovingConcaveDemo. I managed to get the collisions using the following calls at each time step: m_trimeshShape->postUpdate(); m_trimeshShape->updateBound(); body->setActivationState(DISABLE_DEACTIVATION); ho...
by topcomer
Sat Sep 22, 2007 12:18 am
Forum: General Bullet Physics Support and Feedback
Topic: gimpact and deformable meshes
Replies: 4
Views: 2470

Re: gimpact and deformable meshes

With GImpact shapes you must call postUpdate() and then updateBound() after altering the mesh vertices. Please take a look to the documentation: http://gimpact.sourceforge.net/reference_html/programmers_guide.html Thanks. Att : Francisco thanks for the reply. I thought that postUpdate() and updateB...
by topcomer
Fri Sep 21, 2007 12:08 pm
Forum: General Bullet Physics Support and Feedback
Topic: gimpact and deformable meshes
Replies: 4
Views: 2470

gimpact and deformable meshes

I've started to use GIMPACT and I thought it would be good to edit the MovingConcaveDemo replacing the bunny with my mesh. I could create the mesh using initGImpactCollision() and move my mesh around with the mouse as a rigid body. So the next step was to move the vertices coordinates to deform the ...
by topcomer
Mon Sep 17, 2007 2:29 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: soft body solver + ?
Replies: 11
Views: 5441

Re: soft body solver + ?

Is it a good idea to use ODE+Bullet+Gimpact? Bullet and Gimpact would handle collisions and ODE the rigid bodies and terrains of whatever shape. Does someone have a better solution? Thanks. You could go for just Bullet and GImpact. It wonder why you would introduce ODE to this mix, as Bullet can do...
by topcomer
Mon Sep 17, 2007 9:44 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: soft body solver + ?
Replies: 11
Views: 5441

Re: soft body solver + ?

Is it a good idea to use ODE+Bullet+Gimpact? Bullet and Gimpact would handle collisions and ODE the rigid bodies and terrains of whatever shape. Does someone have a better solution? Thanks. You could go for just Bullet and GImpact. It wonder why you would introduce ODE to this mix, as Bullet can do...
by topcomer
Thu Sep 13, 2007 5:06 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: soft body solver + ?
Replies: 11
Views: 5441

Re: soft body solver + ?

If you already have a wrapper for ODE, it should be even more simple to switch to Bullet. (you only need to make the changes inside wrapper). It would make support easier, just use this forum. Hope this helps, Erwin The main reason I want to use bullet rather than ODE is indeed this very forum (and...
by topcomer
Thu Sep 13, 2007 2:15 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: soft body solver + ?
Replies: 11
Views: 5441

Re: soft body solver + ?

Is it a good idea to use ODE+Bullet+Gimpact? Bullet and Gimpact would handle collisions and ODE the rigid bodies and terrains of whatever shape. Does someone have a better solution? Thanks. You could go for just Bullet and GImpact. It wonder why you would introduce ODE to this mix, as Bullet can do...
by topcomer
Fri Sep 07, 2007 3:05 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: soft body solver + ?
Replies: 11
Views: 5441

soft body solver + ?

Hi everyone, I've developed a soft body stand-alone solver for volumetric meshes (with AABBvsAABB collision detection which is independent from the solver itself) which needs now to be interfaced with a rigid body world. I have already implemented an interface class from the follwing idea: 1- collis...