Contribution - Infinigen to Isaac Sim Converter

[shiven2001]

Hi, I want to make a contribution to isaac sim. I created a script which can allow for fixing the issues of the generated infinigen usd files (used in replicator examples of isaac sim) for better SDG pipelines or other use cases. There seems to be a lot of issues with directly importing the indoor apartments made my infinigen to isaac sim. The following fixes can be introduced using my script:

1. Creating new meshes for GeomSubsets imported from Infinigen into individual meshes for better segmentation and rendering.
2. Added distant lighting to the rooms and also shadow casting fixes to the windows so that light can pass through the windows.
3. Changed the lighting of ceiling lights and fixed ceiling lighting issues with intensity
4. Support for changing asset materials given by infinigen with custom textures for compatibility issues fix (using premade .mdl files).
5. Fixing defect UV positions during import from Infinigen to Isaac Sim
6. Updating camera centric properties for imported camera rigs for larger field of view (aperture to 1.0)
7. Fixed the wall shader material assignment issue

Please let me know if my contribution is possible.