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leggedrobotics / raisimLib

RAISIM, A PHYSICS ENGINE FOR ROBOTICS AND AI RESEARCH
http://www.raisim.com
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Segmentation fault for articulated system with 0 movable joints #51

Closed wxmerkt closed 4 years ago

wxmerkt commented 4 years ago

While this may sound like a contradiction, it's perhaps useful to debug a URDF that only contains fixed or no joints at all (root link only).

To reproduce: call addArticulatedSystem on a URDF with a base link and no further joints or links.

Observed behaviour: Segmentation fault.

Expected behaviour: Adds the system with no movable joint (single rigid body) or throws an exception saying that at least one movable (revolute, continuous, prismatic, spherical) joint is required.

jhwangbo commented 4 years ago

I know this does not work in raisim. I doubt if this can be useful but I'll fix this in v1.0.

Does your URDF have no movable joints?

wxmerkt commented 4 years ago

No, this happened when trying to work on a minimum working example for #50. I have seen URDFs with no movable joints though (some people use them to load collision environments, e.g., tables or thelike).

jhwangbo commented 4 years ago

This will give me a segfault for a different reason. Such a system is not supported in RaiSim.

It will be supported in v1.0. It is going to be an easy fix. I just couldn't anticipate that all fixed systems can be useful for some people...

wxmerkt commented 4 years ago

Okay - I was more keen to have an exception thrown or error shown than a segmentation fault :-).