Hello.
I have a question.
Downloadable Asset Packs — Omniverse USD
I downloaded a USD Explorer Sample Assets Pack file from above link. (A factory environment)
It doesnt have any omnigraph or script in that USD.
But it can play simulation. Facilities move chasis of car, Robots respot and handle part of car too.
How to simulate facilities in this USD.
Is there a special way to simulate except omnigraph or script?
The factory environment you downloaded from the USD Explorer Sample Assets Pack relies on pre-baked (keyframed) animation data, not true dynamic physics simulation. Specifically, the USD file makes use of TimeSamples, which are arrays of values at different frames/timestamps that store the animation curves for object transforms and motion.
This means that when you “run” the simulation in Omniverse Isaac Sim, you are seeing objects follow predetermined motion paths that were authored in advance, rather than reacting to physics forces or simulation in real-time.
If you inspect the USD file, you can look for "timeSamples" fields under transform or animation-related attributes—these list explicit values at given timecodes, as described in the OpenUSD documentation on TimeCodes and TimeSamples.