Search found 26 matches

by thloh85
Tue Jan 12, 2010 12:47 am
Forum: General Bullet Physics Support and Feedback
Topic: Bug report on tGeneric6DOFSpringConstraint with solution
Replies: 1
Views: 1006

Bug report on tGeneric6DOFSpringConstraint with solution

Small fix btGeneric6DOFSpringConstraint's setEquilibriumPoint has an issue. It's too small of a fix, I'm lazy to create a patch. void btGeneric6DofSpringConstraint::setEquilibriumPoint(int index) { btAssert((index >= 0) && (index < 6)); calculateTransforms(); if(index < 3) { m_equilibriumPoint[index...
by thloh85
Wed Dec 02, 2009 9:22 am
Forum: General Bullet Physics Support and Feedback
Topic: btGeneric6DofSpringConstraint explodes
Replies: 2
Views: 1396

Re: btGeneric6DofSpringConstraint explodes

Hi, Thanks for the testing. And I'm sorry for my late reply. I think I did some mistake describing my problem. Actually, I added a spring to body A and B, and further added another spring to body B and C, where body A, B, C all has mass of 1. Then the spring begin to become unstable. Is there any al...
by thloh85
Mon Nov 16, 2009 2:30 pm
Forum: General Bullet Physics Support and Feedback
Topic: btGeneric6DofSpringConstraint explodes
Replies: 2
Views: 1396

btGeneric6DofSpringConstraint explodes

Hi all, I was just trying out the stability of btGeneric6DofSpringConstraint, but it seems that when the setStiffness is set too high, the spring starts to explode. My current wild guess is that the spring springs to and fro too fast, causing them to go unstable. To reproduce this, just simply creat...
by thloh85
Thu Nov 05, 2009 12:28 am
Forum: General Bullet Physics Support and Feedback
Topic: addConstraint explodes
Replies: 1
Views: 829

addConstraint explodes

Hi all, I've got a problem with addConstraint, which I believe is a bug. The reproduction case is simple 1. create 2 rigid body 2. body->setCollisionFlags(body->getCollisionFlags() | btCollisionObject::CF_NO_CONTACT_RESPONSE) for one of them 3. setCenterOfMassTransform so that they overlap each othe...
by thloh85
Thu Jul 23, 2009 3:39 am
Forum: General Bullet Physics Support and Feedback
Topic: Bullet 2.75-rc3 build errors AND CONGRATULATIONS TO ERWIN!
Replies: 5
Views: 1633

Re: Bullet 2.75-rc3 build errors AND CONGRATULATIONS TO ERWIN!

Congratulations Erwin. Let's welcome Erwin jr. to the bullet world :)
by thloh85
Wed Jul 22, 2009 2:01 am
Forum: General Bullet Physics Support and Feedback
Topic: How can i detect which Objects (ID's) collide in Bullet??
Replies: 3
Views: 1218

Re: How can i detect which Objects (ID's) collide in Bullet??

There is a function called setUserPointer in btRigidBody(or somewhere if it's not there, I couldn't recall) AFAIK, therefore, use setUserPointer with whatever that identifies your body, and getUserPointer to check them.

Hope this helps
by thloh85
Wed Jul 22, 2009 1:57 am
Forum: General Bullet Physics Support and Feedback
Topic: Correct way to move objects around in game
Replies: 7
Views: 4179

Re: Correct way to move objects around in game

No you DON'T have to do collision detection manually for kinematic body, there will be collision by default. The thing with kinematic body is that when other object hits it (or "pushes" it), this kinematic body will NOT move in anyway, so, if you want your kinematic object to react to those, you'll ...
by thloh85
Mon Jun 29, 2009 7:39 am
Forum: General Bullet Physics Support and Feedback
Topic: Performance optimization with btDiscreteDynamicsWorld.cpp
Replies: 4
Views: 1728

Re: Performance optimization with btDiscreteDynamicsWorld.cpp

Looks like a nice one. Hope your patch gets integrated.
by thloh85
Mon Jun 22, 2009 3:34 am
Forum: General Bullet Physics Support and Feedback
Topic: btGImpactMeshShape bouncing for first collision?
Replies: 7
Views: 3391

Re: btGImpactMeshShape bouncing for first collision?

Hello projectileman,

I'm wondering when can we use SAT instead of GJK in GImpact? Looking forward to this :)

Thanks
by thloh85
Mon Jun 15, 2009 7:25 am
Forum: General Bullet Physics Support and Feedback
Topic: Possible heap corruption with 2.75?
Replies: 4
Views: 1300

Re: Possible heap corruption with 2.75?

I moved my code from 2.5X -> 2.7X -> 2.75, nothing much changed on my side, no heap corruption. I'm not 100% sure it doesn't have any problem, I'm just saying my code (which is only about 5000 effective lines) doesn't have any.
by thloh85
Mon Jun 15, 2009 1:09 am
Forum: General Bullet Physics Support and Feedback
Topic: ApplyCentralForce
Replies: 1
Views: 1099

Re: ApplyCentralForce

It all depends on whether you want to apply a force continuously or just one time. For one timer, just use the applyForce or applyCentralForce. For continuous force application, you could calculate the dt, or you could just set the applyForceImpulse of the rigid body. I'm not a guru of bullet, but A...
by thloh85
Sun Jun 14, 2009 3:11 pm
Forum: General Bullet Physics Support and Feedback
Topic: btGImpactMeshShape bouncing for first collision?
Replies: 7
Views: 3391

Re: btGImpactMeshShape bouncing for first collision?

The problem is with the margin of the shape, set it to 0.05, everything works.
Bullet rocks, GImpact rocks as well!!!

Thanks Erwin, projectileman, and the whole bullet team!!!
by thloh85
Sun Jun 14, 2009 2:36 pm
Forum: General Bullet Physics Support and Feedback
Topic: btGImpactMeshShape bouncing for first collision?
Replies: 7
Views: 3391

Re: btGImpactMeshShape bouncing for first collision?

It helped for the non-bouncing stuffs, but the created shape became extremely unstable(ie. it shakes indefinitely on the ground), any idea?
by thloh85
Thu Jun 11, 2009 1:44 pm
Forum: General Bullet Physics Support and Feedback
Topic: btConvexHullShape unstable when resting
Replies: 1
Views: 767

Re: btConvexHullShape unstable when resting

Problem solved. After debugging for a whole day, it turns out I'm doing a stupid mistake, description below. Note to users that might have this problem. If you ever register InternalStepCallback, do NOT clear the manifold there (clearManifold function). It'll cause stability issue. Thanks a lot for ...
by thloh85
Wed Jun 10, 2009 3:37 pm
Forum: General Bullet Physics Support and Feedback
Topic: btConvexHullShape unstable when resting
Replies: 1
Views: 767

btConvexHullShape unstable when resting

Hello, I used btConvexHullShape (with btTriangleMesh as the tris interface) to construct a couple of stuffs (starting with box). The problem is, when it landed on the floor (a static object), it keeps on dancing around. The video below shows my problem. The same problem goes when a shape stacks on t...