Search found 133 matches

by John McCutchan
Wed Dec 09, 2009 3:39 pm
Forum: General Bullet Physics Support and Feedback
Topic: Detect collision between swept kinematic objects?
Replies: 1
Views: 1974

Re: Detect collision between swept kinematic objects?

Hi Ola,

You can use a linear convex cast and possibly a ghost object to cull out far away objects. Please see the kinematic character controller for example code.

John
by John McCutchan
Mon Oct 26, 2009 3:30 pm
Forum: General Bullet Physics Support and Feedback
Topic: btRigidBody and Heightfield fluid
Replies: 10
Views: 4447

Re: btRigidBody and Heightfield fluid

Hi, Buoyant objects can have any convex collision shape (not just spheres). At some point I would like to revisit this and expand on it. Performance is a major issue. Supporting non-convex shapes should be fairly easy and there was a paper at SIGGRAPH this year that talked about an algorithm for non...
by John McCutchan
Fri Oct 23, 2009 3:36 pm
Forum: General Bullet Physics Support and Feedback
Topic: btRigidBody and Heightfield fluid
Replies: 10
Views: 4447

Re: btRigidBody and Heightfield fluid

Sorry, I meant it shouldn't.

John
by John McCutchan
Tue Oct 20, 2009 3:27 pm
Forum: General Bullet Physics Support and Feedback
Topic: btRigidBody and Heightfield fluid
Replies: 10
Views: 4447

Re: btRigidBody and Heightfield fluid

Hi,

You should have a crash there.

Does the btHfFluid demo work properly for you?

John
by John McCutchan
Mon Oct 19, 2009 5:15 pm
Forum: General Bullet Physics Support and Feedback
Topic: btRigidBody and Heightfield fluid
Replies: 10
Views: 4447

Re: btRigidBody and Heightfield fluid

Hi,

You need to use the btHfFluidBuoantConvexShape as well as set the "floatyness".

John
by John McCutchan
Fri Oct 16, 2009 4:08 pm
Forum: General Bullet Physics Support and Feedback
Topic: Heightfield fluid demo questions
Replies: 2
Views: 1976

Re: Heightfield fluid demo questions

Hi,

gridCellWidth is in meters and the width of the water surface is in gridCellWidth * numNodesWidth. The height is similar. The m_volumeDisplacementScale controls what percentage of displaced water is moved per frame. m_horizontalVelocityScale is unused.

John
by John McCutchan
Thu Oct 15, 2009 3:01 pm
Forum: General Bullet Physics Support and Feedback
Topic: Weird Code, maybe buffer overrun in btBoxBoxDetector::inte..
Replies: 3
Views: 2082

Re: Weird Code, maybe buffer overrun in btBoxBoxDetector::inte..

Hi teravus,

Just run your build under valgrind, it will immediately tell you if your assumption is right.

John
by John McCutchan
Tue Mar 31, 2009 8:09 pm
Forum: General Bullet Physics Support and Feedback
Topic: Using MotionState with CharacterController
Replies: 6
Views: 4454

Re: Using MotionState with CharacterController

Hi,

btMotionState is currently only available for rigid bodies. You can always manually synchronize your graphics transformation with one obtained from the character controller.

As Sorlaize said, you can use getWorldTransform() to obtain the current transformation of the btGhostObject.

HTH,
John
by John McCutchan
Tue Feb 10, 2009 4:01 pm
Forum: General Bullet Physics Support and Feedback
Topic: Placement new check bug..
Replies: 2
Views: 1801

Re: Placement new check bug..

Hi,

Could you post the output from the compiler?

Thanks,
John
by John McCutchan
Mon Jan 26, 2009 9:18 pm
Forum: General Bullet Physics Support and Feedback
Topic: Current SVN Cmake HtFluidDemo broke
Replies: 6
Views: 2886

Re: Current SVN Cmake HtFluidDemo broke

FYI,

I just committed a fix for this problem. I had fixed it last week but I forgot to commit it.

Thanks,
John
by John McCutchan
Mon Jan 26, 2009 4:37 pm
Forum: General Bullet Physics Support and Feedback
Topic: Current SVN Cmake HtFluidDemo broke
Replies: 6
Views: 2886

Re: Current SVN Cmake HtFluidDemo broke

Hi,

The preferred method for submitting bug fixes to Bullet is to file an issue in the google issue tracker and attach any patches there.

Thanks,
John
by John McCutchan
Thu Jan 22, 2009 3:57 pm
Forum: General Bullet Physics Support and Feedback
Topic: Updated CharacterDemo?
Replies: 2
Views: 1873

Re: Updated CharacterDemo?

Hey Tom,

Could you open an issue in the google code tracker and post your changes there? We can then discuss merging them.

We are aware of the crash and are working on it.

Thanks,
John
by John McCutchan
Mon Dec 22, 2008 6:20 pm
Forum: General Bullet Physics Support and Feedback
Topic: Collision between kinematic and static objects
Replies: 9
Views: 10637

Re: Collision between kinematic and static objects

Jonan, The kinematic character controller does interact with dynamic objects. Dynamic objects will bounce off the KCC and the KCC will move around dynamic objects. The KCC could be extended to say "kick" the dynamic objects instead of moving around them (like static walls.) Kinematic objects are ess...