Double-sided Normals in Mesh Bounding

[stevenLD]

We're using btTriangleMeshShape for our mesh bounding, and have observed behaviour consistent with our polygons having double-sided normals. We transitioned to Bullet from another physics engine that assumed normals based on rotation/order of the vertices passed in to make the polygons.

Does Bullet do anything similar?

Is it possible to have Bullet make (or take in) a set of "normal" normals?

Thanks.

[Erwin Coumans]

We're using btTriangleMeshShape for our mesh bounding, and have observed behaviour consistent with our polygons having double-sided normals. We transitioned to Bullet from another physics engine that assumed normals based on rotation/order of the vertices passed in to make the polygons.

Does Bullet do anything similar?

You can best use btBvhTriangleMeshShape, btTriangleMeshShape is only meant as internal (unoptimized) fixed triangle meshes. btBvhTriangleMeshShape add acceleration structure for triangle meshes.

Bullet doesn't require triangle normals, it can perform collision detection with double sided triangle meshes.

Why would you need single-sided triangles?

Thanks,
Erwin

By the way: btBvhTriangleMeshShape is only for fixed world geometry, that is not moving. If you need moving triangle meshes, either use btConvexHullShape, btCompoundShape or GIMPACT (see MovingConcaveDemo).