I have a robot model as URDF file, the import and conversion to a .usd file worked so far.
To start the simulation, I work with the Python API and a write a Python script with some different classes. I use the “robot” class from Isaac Sim API to create a robot object and equip it with suitable controllers in a later step (using the apply_action method from the Articulation class).
However, after calling the world.reset() method, the robot behaves very weird, flying around in the environment instead of “falling” down to the groundplane due to gravity.
I am currently working with the Isaac Sim 2022.2.0 release. I have analyzed the robot model again in detail and found that there was an overlap of two components in the collision mesh, I have corrected this and since this moment this works.
Maybe it could be helpful in a later release to include some kind of check if the collision mesh was created correctly.