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NVIDIA / warp

A Python framework for high performance GPU simulation and graphics
https://nvidia.github.io/warp/
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Unstable integration with Symplectic Euler #144

Closed ClemensSchwarke closed 1 year ago

ClemensSchwarke commented 1 year ago

Hi,

I am trying to run the quadruped example using the provided SemiImplicitIntegrator but the simulation is highly unstable. I tried to tune the stiffness parameters but with no success. In my understanding, this behavior is mainly caused by the constraint forces between joints. Is there anything I might be overlooking?

Thanks in advance!

eric-heiden commented 1 year ago

Hi Clemens,

The Euler integrator needs a finer time resolution to remain stable. So you can try a higher number of sim_substeps here (e.g. 16 worked for me): https://github.com/NVIDIA/warp/blob/main/examples/example_sim_quadruped.py#L35

ClemensSchwarke commented 1 year ago

Thanks a lot for the quick and helpful response Eric! And sorry for missing the obvious.

Cheers, Clemens