Also why is it that I get a error when trying to find the local inertia for triangle meshes, also when setting the meshes's mass to anything other then 0 why does everything fall threw it.
btBvhTriangleMeshShape is only for static, non-moving, non-dynamic objects with mass zero. If you want to use moving objects, you can better approximate the shape using a btConvexHullShape, or btCompoundShape with multiple simple shapes. Alternatively use btGimpactMeshShape, see MovingConcaveDemo how to use this.
Does anyone know how to properly add to a triangle mesh that has already been added to the world. Found out that the addTrianglesToMesh and updateMesh functions dont really work :S.. I have the drawing ofcouse but the collision body isnt updated, or something...
You cannot add triangles to it, after construction.
Hope this helps,