Runtime friction and restitution randomization bug with GPU simulation fixed in Isaac Sim 2022.2.1

Hi everyone,

I’m pleased to announce that after quite a bit of effort, the Isaac Sim and PhysX teams were able to track down and fix an important bug that could impact runtime domain randomization of physics material properties.

In previous versions of both Isaac Sim as well as the standalone Isaac Gym preview releases, attempts to randomize friction or restitution rigid_shape_properties parameters at runtime using the IsaacGymEnvs or OmniIsaacGymEnvs Domain Randomization APIs would not actually update those physics properties in the default GPU simulation pipeline. Setting random friction or restitution values at start-up time was working normally, but no updates once simulation started would actually propagate to the physics simulation.

This bug has the potential to impact sim-to-real performance when training with small numbers of environments, though our evaluation of the fix has not shown substantial differences when training the Shadow Hand or Allegro Dextreme environments which use 16k or more environments during training. If you’re not able to upgrade to Isaac Sim 2022.2.1 for Sim-to-real work, we suggest that you increase the number of environments you are training simultaneously.

Many kind thanks to @user58271, NJ-WuSiyang, @HarryYang and others in the forums and on GitHub who noticed this problem and reported it!

Take care,

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