Is it possible to add Mujoco's sites?

[MRiabov]

Hello, I'm trying to set up a simulation where I need to track not just general body positions, but highly specific locations within those bodies - I want to simulate conductivity of electrical devices (via external sim).

In MuJoCo (as far as I understand), the best way to do it is by adding a site - i.e. a point constrained to a body.

I'm reading through gs.morphs.MJCF and seeing:

class MJCF(FileMorph):
    """
    Morph loaded from a MJCF file. This morph only supports `RigidEntity`

So no site support to genesis, as I understand.

Sites should be a simple feature. is there no way of adding them to genesis atm?

Thank you!

[duburcqa]

It seems that what you are looking for is a fixed frame (aka a link without inertia, nor visual and collision geometries). That is all. This is already supported, just make sure to set the optional argument links_to_keep in MJCF morph!