Mysteriously can't load Robot URDF, no helpful error messages

I am trying to load a custom URDF into RobotBuilder in UnrealEngine following these directions https://docs.nvidia.com/isaac/isaac_sim/plugins/robot_builder/urdf.html#new-urdf-setup It is not based on any of the example robots.

I have the Isaac sim source from here: https://github.com/NvPhysX/UnrealEngine/tree/IsaacSim_1.2

When I tried it, Unreal crashed. When I debug it, in Robot.cpp at line 1278 the call to importModel returns nullptr. There is nothing in the output to suggest what the problem might be with my URDF. importModel is closed source.

Does anyone have any suggestions on what I can do to debug this?

Hi Robert,

We no longer support the Isaac Sim based on UE4.
Why don’t you try the latest Isaac Sim 2020.1 which is built on Omniverse.
Here is the link: [https://developer.nvidia.com/isaac-sim]

Kindly,
Liila

Thanks for getting back to me. I was finally able to get the model to load by removing the inertial sections. Unfortunately UE4 is a hard requirement so I’ve moved on to another solution. Would have been nice if the main Isaac pages had been updated to note the Unreal discontinuation, would have saved me 4 days wasted.

Hi Robert,

Yes, you are right, we will add that note.

Kindly,
Liila