I had a few questions regarding collision meshes in Isaac Sim. To provide brief context, we are trying to import many household objects into Isaac Sim, natively from their URDF format into omniverse’s native USD format.
The Convex Decomposition flag in the URDF importer seems to be broken. Toggling it seems to produce no difference in output behavior (I observed that the visualized collider mesh is the default “convexHull”.)
Manually setting the collider for an already-imported URDF to be “convexDecomposition” seems to significantly slow down runtime performance. This decomposition does not seem to be saved offline, as far as I can tell.
Manually setting the collider for an already-imported URDF to be “meshSimplification” appears to be unusable by the isaac dynamics module (I get a warning that says that it is “falling back to convexHull” since meshSimplification is not supported.)
^This additionally produces strange behavior, such as mismatch between the collision mesh and visual mesh if I scale and move the object around a scene.
The “convexDecomposition” method would be the most ideal, but the significant runtime slowdown is inhibiting.
So, my main question:
How can I keep the already-convex-decomposed .obj collision mesh linked to the USD file generated from an imported URDF? These have already been decomposed into convex components, which I can even visualize by adding a reference to this file in the stage, but I don’t know the proper way to make sure isaac sim treats these individual mesh components as a collision mesh. (The APIs + docs don’t seem to provide much help, unfortunately).
Any help would be greatly appreciated! Thanks!