usd2sdf collapses mesh scale by 1000x #47
Description
Describe the bug
When converting a .usd scene from Isaac Sim 4.5.0 to .sdf using usd2sdf ( gz-usd ), the resulting models exhibit extremely small geometry and completely missing textures — appearing as solid black or invisible in Gazebo Harmonic.
This appears to be caused by incorrect scale transformation during conversion, leading to rendering and usability failure in simulation.
To Reproduce：Ubuntu 22.04 , ROS2 Humble , Gazebo Harmonic
Create a scene in Isaac Sim 4.5.0 with a mesh scaled to (0.003, 0.1, 0.001)
Export as .usd
Run: usd2sdf input.usd output.sdf
Load output.sdf in Gazebo Harmonic
Expected Behavior:
The mesh should retain its original scale proportions
Textures and materials should be preserved or mapped appropriately
Model should be visible and correctly sized in Gazebo
Actual Behavior
The generated SDF contains drastically incorrect scale values:
The X and Z scale values are ~1000x smaller than expected
Models become microscopic or invisible in Gazebo