USD->SDF problem converting a stage to a sdf world from Isaacsim5 to Gazebo Harmonic

[LeonardoMontella]

When I convert a .usd world created in Isaac Sim 5 into an .sdf file to be opened in Gazebo Harmonic, all the assets present in the world disappear after the conversion. As a result, the resulting .sdf file represents an empty world.

I have tried saving the .usd stage in several ways — both with and without flattening, and using relative paths to the models (for which I have both .usd and .sdf versions) — but none of these approaches have worked.

[Xinyu-Sheng]

I'm encountering a similar issue when converting a .usd scene created in Isaac Sim 4.5.0 to an .sdf file for use in Gazebo Harmonic. The resulting .sdf file contains models with extremely small geometric volumes and completely missing textures—everything appears as solid black in Gazebo.

Notably, in Isaac Sim, the original mesh scale is explicitly set to (0.003, 0.1, 0.001), but after conversion using usd2sdf, the generated SDF contains the following:
<geometry> <mesh> <uri>StairsSlope/Cube_01/StairsSlope/Stairs/Cube_01/Cube_01.dae</uri> <scale>9.0000001564621932e-06 0.010000000298023226 1.0000000949949049e-06</scale> </mesh> </geometry>
These scale values differ from the original by several orders of magnitude, causing the models to become nearly invisible or effectively "disappear" in Gazebo.