Fail to load built-in material

Hi, I added some built-in materials into an object.
I can’t load these materials now

 [Error] [omni.usd] [Watcher] Failed to resolve USD Asset Identifier '' from prim '/World/_01_chassis_pcb/Looks/Green_Glass/Shader'

How to fix this, thanks!

Hi - Sorry for the delay in the response. Let us know if you still having this issue/question with the latest Isaac Sim 2022.2.1 release.

Failed to create MDL shade node for prim ‘/World/Apriltags/Looks/AprilTag_ID_02/Shader’. Unsupported identifiers.

Hey all I have a similar problem but with the apriltag

I got the similar error as doing this example

2023-07-19 01:36:03 [Error] [omni.usd] [Watcher] Failed to resolve USD Asset Identifier ‘./materials/Pine_bark.mdl’ from prim ‘/Replicator/SampledAssets/Population_ed33029f/Cached31_Prim_pi/Looks/Pine_bark/Pine_bark’

Hi @hannah.schieber - The error message you’re seeing suggests that there’s an issue with the Material Definition Language (MDL) shader node for the AprilTag. This could be due to a few reasons:

  1. The shader file might not be found: Ensure that the shader file is in the correct location and the path to it is correctly specified in your USD file.
  2. The shader might not be compatible: The shader might be written in a version of MDL that is not supported by the version of Isaac Sim you’re using. You might need to update your Isaac Sim or modify the shader to a compatible version.
  3. The shader might have errors: There might be syntax errors or other issues in the shader file itself. You can try opening the shader in a text editor and checking for any obvious issues.

Hi @darien.wei - The error message you’re seeing indicates that the system is unable to find the Material Definition Language (MDL) file Pine_bark.mdl in the ./materials/ directory relative to the location of your USD file.

Here are a few things you can check:

  1. File Location: Make sure that the Pine_bark.mdl file is indeed located in the ./materials/ directory relative to your USD file. If it’s not, you’ll need to move it there or adjust the path in your USD file to point to the correct location.
  2. File Name: Check that the file name is spelled correctly and matches exactly with the name in your USD file. File names are case-sensitive, so make sure the capitalization matches as well.
  3. File Path: The path to the MDL file in your USD file is a relative path (as indicated by the ./ at the start). This means it’s relative to the location of the USD file. If your USD file and MDL file are not in the expected locations relative to each other, you’ll need to adjust the path.
  4. File Format: Make sure that the Pine_bark.mdl file is a valid MDL file. You can try opening it in a text editor to see if it contains valid MDL code.