[Proposal] Add support for spawning meshes from obj and stl files

[han-xudong]

Proposal

Adding support for spawning meshes from .obj and .stl files.

Motivation

When I was trying to spawn a mesh, I found that only several kinds of geometries were supported instead of complex structures from OBJ or STL files. And I also found that these geometries were generated by trimesh which can load meshes from OBJ and STL files. Therefore, it's available to create a function based on trimesh to make it work.

Alternatives

• Add spawn_mesh_file in source/isaaclab/isaaclab/sim/spawners/meshes/meshes.py
• Add MeshFileCfg in source/isaaclab/isaaclab/sim/spawners/meshes/meshes_cfg.py
• Update source/isaaclab/isaaclab/sim/spawners/meshes/__init__.py

Checklist

• [x] I have checked that there is no similar issue in the repo (required)

Acceptance Criteria

Add the criteria for which this task is considered done. If not known at issue creation time, you can add this once the issue is assigned.

• [ ] Support spawning meshes from OBJ and STL files.

[RandomOakForest]

Thank you for posting this proposal. The team will review it.

[han-xudong]

@RandomOakForest Hi~ Is there any updates? I think the PR is quite clear.