Real-Time Physics Simulation Forum

I know .... it was 3 years ago .....

Flix wrote:However what about the "gCompoundChildShapePairCallback" ? Does it work or not ?

It works, thank!

Edit: Don't forget to set "gCompoundCompoundChildShapePairCallback" too.

it seems odd to me that the I can see the rigidBody shape moving first and then the bullet moving afterwards at each step. Is that okay? Yes, it is ok. I do that for more than a year without any problem. If I manage "order of update" well enough, I will not suffer 1-frame-lag that you con...

1. Your image is too big, it breaks my screen. :lol: 2. You accidentally created the thread twice (another one without attachment). Delete that before any admin can see! 3. Did you test it with a more simple model e.g. a cube with in a compound? 4. Did you test it with a simple shape (not compound a...

btRigidBody::setLinearFactor ?

The second part in http://bulletphysics.org/mediawiki-1.5. ... e_Snippets .

It doesn't solve the issue directly though.

Agree, I want to know too.
Similar feature like AABB query also doesn't work for subshape, I think.

I think I have to calculate it based on a btCompoundShape myself.

I think the easiest way is to applyImpulse(customGravity) every time-step.

I doubt whether it has any disadvantage compared to drleviathan's answer.

I think, in benelot's scene, it should be in equilibrium. Roughly speaking, I think OP wants a special hard (glue) constraint. Hard constraint doesn't exist in Bullet. (Please fix me if I am wrong.) The easiest way is what Benelot mentioned (average v,w,position,orient ?), but the result would be mo...

I called btMatrix3x3::diagonalized() and find unexpected return value. Input: (Note that it is almost diagonal.) In btMatrix3x3::diagonalize(btMatrix3x3& rot, btScalar threshold, int maxSteps) :- this = {6.66666674e-05, 9.09494702e-13, 0.000000000, 0.000000000} {-9.09494702e-13, 6.66666674e-05, ...

Sorry, I don't think "collision filters" can solve OP's problem. Agree with Benelot that what OP asked for is potentially against Physics rule - OP is probably developing a game. The solution should be "custom collision response", but I don't know how, specificially. There may be...

I think Bullet doesn't support 0-thickness shape very well, except infinite plane.
Almost all shapes should have thickness and it is the best to be watertight (enclose a certain volume).
I guess your shape should be extruded a bit.
I don't know any other ways, and I am just a beginner.

Wow, it is such an honor for me that the legendary scorpion81 reply, thank! I want to find all plain shapes (of enemy) in a certain world's AABB. They will be damaged by hero's area-damage weapon in a game. I am afraid that finding adjacent shapes (from connections of compoundConstraint) is not what...

In a world that contains many btRigidBody , and each btRigidBody has btCompoundShape as its shape, how can I know which plain shapes (small shape inside btCompoundShape ) are in a certain AABB volume? Here is how I currently call. It works, but I can only get callback as body, not shape. bool proces...

remove rigidBody before constraint from the world?

6000 vertices x 10-20 bodies I have tested : 4000 dynamic cubes can reach the system limit of Bullet for a simple game. According to official guide, triangle meshes management is poorly optimized relative to cube. Thus your situation may reach the threshold. Higher amount of bodies & lower amou...

How many vertex per body?