Future plans for collider_type options in UrdfImporter

[YongcanZhou]

Hi everyone,

I noticed that in Isaac Lab 2.2, the mesh_converter_cfg used the parameter

collision_approximation: str = "convexDecomposition"

with several valid options: "convexDecomposition", "convexHull", "boundingCube", "boundingSphere", "meshSimplification", and "none".

In version 2.3, this has been replaced by

mesh_collision_props: schemas_cfg.MeshCollisionPropertiesCfg = None

which allows setting detailed mesh approximation properties such as

ConvexHullPropertiesCfg, ConvexDecompositionPropertiesCfg, BoundingCubePropertiesCfg, TriangleMeshSimplificationPropertiesCfg, and SDFMeshPropertiesCfg.

This gives much more flexibility and control over the collider shape.

However, in both isaaclab2.2 and 2.3, the urdf_converter_cfg still defines:

collider_type: Literal["convex_hull", "convex_decomposition"] = "convex_hull"

which only supports two collider types.

I wanted to ask if there are any plans to extend the urdf_converter_cfg to support additional collider types, for example, mesh simplification or other approximation methods, similar to what’s now available in the mesh converter configuration.

This would help when converting URDF models with complex shapes that are not well represented by convex hull or convex decomposition methods.

Thanks!
source:  https://github.com/isaac-sim/IsaacLab/discussions/3863

I tried modifying the code, but I found that this part requires isaacsim to implement:

                    if (config.convexDecomp == true)
                    {
                        physicsMeshAPI.CreateApproximationAttr().Set(pxr::UsdPhysicsTokens.Get()->convexDecomposition);
                    }
                    else
                    {
                        physicsMeshAPI.CreateApproximationAttr().Set(pxr::UsdPhysicsTokens.Get()->convexHull);
                    }
source: https://github.com/isaac-sim/IsaacSim/blob/main/source/extensions/isaacsim.asset.importer.urdf/plugins/isaacsim.asset.importer.urdf/UrdfImporter.cpp#L584

Is it possible to implement this for better use of self-collision detection?

[vick-yu]

Thanks for raising this and for linking the Isaac Lab discussion.

This topic is already being tracked in the Isaac Lab discussion here: isaac-sim/IsaacLab#3863, which covers the same request about extending urdf_converter_cfg/UrdfImporter to support additional collider approximation types similar to the mesh converter configuration.

To keep the conversation and any updates in one place, this thread will be closed as a duplicate of that discussion. Please follow and continue the discussion there (and if an issue is opened from it, that will be the canonical place for status updates).