Search found 32 matches

by topcomer
Thu Aug 18, 2011 8:28 pm
Forum: General Bullet Physics Support and Feedback
Topic: how to use gimpact trimesh-trimesh?
Replies: 14
Views: 8999

Re: how to use gimpact trimesh-trimesh?

I know this is coming a bit late (4 years late haha), but did you ever get it working. That is, get the program to output the colliding vertices? If so, care to share the solution? Thanks I think I did but I don't remember how and I am on holiday and don't have my external HDD with my old code with...
by topcomer
Mon May 05, 2008 6:43 pm
Forum: Non-technical forum and license/patent discussion
Topic: Soft bodies early preview, legal?
Replies: 1
Views: 9253

Soft bodies early preview, legal?

Nathanael wrote: Thanks,

Yes, the solver itself is based on Matthias Muller's work, mainly because its simple to implement and provide velocities which are needed for some future features.
it may sound stupid since I'm not a lawyer but is that legal?
by topcomer
Wed Dec 19, 2007 9:02 am
Forum: General Bullet Physics Support and Feedback
Topic: erase static flag from kinematic bodies
Replies: 3
Views: 2211

Re: erase static flag from kinematic bodies

I have noticed the same thing (making a body kinematic by changing the collision flags to include CF_KINEMATIC does not remove the CF_STATIC flag) and thought it odd. However, it does work for me. Apparently, kinematic bodies are "special case" versions of static bodies. Thanks for the reply. In my...
by topcomer
Fri Dec 14, 2007 2:37 pm
Forum: General Bullet Physics Support and Feedback
Topic: erase static flag from kinematic bodies
Replies: 3
Views: 2211

erase static flag from kinematic bodies

I see that btRigidBody.cpp contains the following: void btRigidBody::setMassProps(btScalar mass, const btVector3& inertia) { if (mass == btScalar(0.)) { m_collisionFlags |= btCollisionObject::CF_STATIC_OBJECT; m_inverseMass = btScalar(0.); } else { m_collisionFlags &= (~btCollisionObject::CF_STATIC_...
by topcomer
Wed Nov 28, 2007 10:36 am
Forum: General Bullet Physics Support and Feedback
Topic: inner simulation steps and callback
Replies: 1
Views: 1010

inner simulation steps and callback

I managed to write a collision callback which gives me all the contact info I need, however I get a seamless stream of contacts coming from the inner simulation steps and I'm hence not able to understand when one of this substeps finishes and the other starts. Is there a way to know that without hav...
by topcomer
Wed Nov 28, 2007 9:50 am
Forum: Release Announcements
Topic: Bullet 2.64 released: all-in-one demos, memory allocators
Replies: 3
Views: 9570

Re: Bullet 2.64 released: all-in-one demos, memory allocators

Just in case one has the same problem, the solution is to change line 44 in btGImpactShape.h from:

typedef btGImpactQuantizedBvh btGImpactBoxSet;

to:

typedef btGImpactBvh btGImpactBoxSet;
by topcomer
Mon Nov 26, 2007 8:55 am
Forum: General Bullet Physics Support and Feedback
Topic: C#/XNA BulletX: Why there is no Contact point sometimes?
Replies: 2
Views: 1322

Re: Why there is no Contact point sometimes?

there are no contact points or no collision response at all?
by topcomer
Fri Nov 16, 2007 9:35 am
Forum: Release Announcements
Topic: Bullet 2.64 released: all-in-one demos, memory allocators
Replies: 3
Views: 9570

Re: Bullet 2.64 released: all-in-one demos, memory allocators

I have a small test case in which collisions cease to work after a while. If you take a virgin version of Bullet (2.63 or later), inside movingConcaveDemo replace the functions shootTrimesh() and clientMoveAndDisplay() with: void ConcaveDemo::shootTrimesh(const btVector3& destination) { if (m_dynami...
by topcomer
Fri Nov 16, 2007 9:34 am
Forum: General Bullet Physics Support and Feedback
Topic: kinematic issue again
Replies: 2
Views: 1600

Re: kinematic issue again

Ok I will use a callback then. I'm only afraid to process redundant contacts, that is something that is detected during the simulation loop but discarded by the solver. Let's say for example that two blocks P and Q collide together but P also with the trimesh at the point A. To avoid penetration, bo...
by topcomer
Thu Nov 08, 2007 4:03 pm
Forum: General Bullet Physics Support and Feedback
Topic: kinematic issue again
Replies: 2
Views: 1600

kinematic issue again

I'm using ConcavePhysicsDemo.ccp with the following modification inside shootTrimesh(): mass =0.f; body->setCollisionFlags( body->getCollisionFlags() | btCollisionObject::CF_KINEMATIC_OBJECT ); body->setActivationState(DISABLE_DEACTIVATION); and the follwing function called just after renderme() in ...
by topcomer
Fri Oct 26, 2007 3:28 pm
Forum: Release Announcements
Topic: Bullet 2.63 released: New Pair Cache, GIMPACT 0.3, Libspe2
Replies: 5
Views: 12292

Re: Bullet 2.63 released: New Pair Cache, GIMPACT 0.3, Libspe2

the issue appears in a virgin version of 2.63 inside movingConcaveDemo just adding: body->setCollisionFlags( body->getCollisionFlags() | btCollisionObject::CF_KINEMATIC_OBJECT ); body->setActivationState(DISABLE_DEACTIVATION); inside shootTrimesh(). Kinematic objects are supposed to have a mass of ...
by topcomer
Thu Oct 25, 2007 8:58 am
Forum: Release Announcements
Topic: Bullet 2.63 released: New Pair Cache, GIMPACT 0.3, Libspe2
Replies: 5
Views: 12292

Re: Bullet 2.63 released: New Pair Cache, GIMPACT 0.3, Libspe2

Not sure what can cause your issue. Can you reproduce it in a Bullet demo, CcdPhysicsDemo? That has a kinematic moving floor with dynamic objects, if you enable the #define USE_KINEMATIC_GROUND Does Bullet 2.64 RC2 still have this issue? Thanks for the report! Erwin the issue appears in a virgin ve...
by topcomer
Wed Oct 24, 2007 8:10 pm
Forum: Release Announcements
Topic: Bullet 2.63 released: New Pair Cache, GIMPACT 0.3, Libspe2
Replies: 5
Views: 12292

Re: Bullet 2.63 released: New Pair Cache, GIMPACT 0.3, Libspe2

are these changes related to kinematic vs dynamic collisions? I just ported my code from 2.6.2 to 2.6.3 and kinematic bodies collide with static objects but not with dynamics, so before looking for the problem I'd like to know if this could be due to some new major change. thanks for the help, alessio
by topcomer
Wed Oct 17, 2007 2:37 pm
Forum: Links, Papers, Libraries, Demos, Movies, Comparisons
Topic: PAL : Physics engine comparison : Source code and results
Replies: 14
Views: 9975

Re: PAL : Physics engine comparison : Source code and results

AntonioMartini wrote:
aboeing wrote: And some of the result data can be graphed here:
http://www.adrianboeing.com/pal/pal_bench_graph.html
it doesn't seem to work, i just see an empty "graph". Am i missing something?

cheers,
Antonio
in my case I missed that it was check the engines you do NOT want to include.
by topcomer
Thu Oct 04, 2007 2:11 pm
Forum: General Bullet Physics Support and Feedback
Topic: how to use gimpact trimesh-trimesh?
Replies: 14
Views: 8999

Re: how to use gimpact trimesh-trimesh?

For each pair of contact points, how many normals I get? In the case this is just one, it can't be normal to both the triangle faces, so it's just the direction of the line connecting the two points? I hope the question is clear. A pair of 'closest points' has one normal that points from point in o...