URDF: Automatic Computation of Mass/Inertia

Hi there!

It seems that both masses and inertia tensors can be computed automatically in both Isaac Gym and Sim:

https://docs.omniverse.nvidia.com/app_isaacsim/app_isaacsim/ext_omni_isaac_urdf.html#parser-settings

For example in the Isaac Gym assets, both versions are present: In the Franka Panda URDF masses/inertias are not provided, while in many other cases these quantities are explicitly represented.

Two related questions:

  1. Are there any drawback in having masses/inertias computed automatically, e.g. computational effects on the real-time performance?
  2. What would be the motivation for deriving masses/inertias manually and extending the URDF with these?

Thanks in advance!
Julian

Hi!
Could you share in isaacgym how to get the value of mass and inertia tensor when it’s not provided in URDF file(only the density is provided)

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