The contact shape deserves its own inspection
A visual mesh is designed to show the object. A collision representation is used by the physics engine to determine contact. They may share geometry, but that choice must suit the runtime and task.
Display colliders independently when reviewing an asset. Pay particular attention to narrow handles, gaps, shelves, container interiors and contact surfaces. A convincing render can hide a collision shape that closes an opening the robot needs.
Choose approximation around the interaction
The UsdPhysics mesh-collision API defines different approximation requests. Actual runtime support must be checked in the selected simulator. A single convex shape cannot represent every cavity in a concave object; a decomposition may preserve more of the structure at additional cost.
NVIDIA's physics fundamentals explain collision representations and their simulation constraints in Isaac Sim. Consult the documentation for your installed version instead of assuming that every USD approximation is handled identically.
Review three task areas
Grasp regions: Can the gripper reach the intended surfaces without colliding with an invisible enclosure? Test the approach as well as the final grasp pose.
Openings: Does the collision representation preserve the free space needed for insertion, placement or retrieval? Check the full path, not only the destination.
Moving parts: Do colliders remain aligned through joint motion? Inspect interactions with neighboring parts near both endpoints.
Keep performance changes measurable
Start with one asset and one representative action. Save a baseline, simplify a collision representation, then repeat the action under the same settings. Compare both task success and runtime cost. Fewer shapes are useful only if they preserve the behavior you need.
If collision tests fail, document the problematic prim, starting pose and interaction. That gives the author a specific correction to make instead of a general request for a higher-quality model.
The free validator can help inspect supported content requirements. Follow that with a runtime test; a schema check cannot establish every contact outcome. Browse the asset library for available package specifications.