Per shape collision group

[IvanEfimov]

Hi,
First of all want say thanks for the great physics library!

I have body with btCompoundShape, which contains many shapes. Need to have ability to define contact group for each shape in the body.
Please tell, how best to make per shape contact group filtering?

I found old similar topic about it, but this is not helps: http://bulletphysics.org/Bullet/phpBB3/ ... f=9&t=1324
btUniformScalingShape can't contain btBvhTriangleMeshShape because this class is not delivered from btConvexShape.
Our bodies can contain btBvhTriangleMeshShape.

[IvanEfimov]

up

[kloplop321]

Only bodies can have their own contact/collision groups. Not shapes.
If you want to have different collision flags, you need to treat each desired collision group as its own possibly compound body.
Then, if you want the body to stay together, use constraints.

[mi076]

I have body with btCompoundShape, which contains many shapes.
...
Our bodies can contain btBvhTriangleMeshShape.

afaik btBvhTriangleMeshShape is not supported as child shape for compound, gimpact too....
(use convex hull). You can also use several submeshes in mesh shapes instead.
Collision tests return part id and index id, so you can identify child shape of compound or submesh of mesh shape with it.

[IvanEfimov]

Thanks for replies!

Oh, It is impossible make body with two Box shapes, each of which will have its own contact group?
PhysX, ODE can.
Maybe exists a sightly way?