Energy/Force Data for Simulated Bodies

[MuGdxy]

Hi @MuGdxy,
I have two questions regarding exporting energy/force:

1. I want to get the total energy/force for each vertex of a specific mesh (for example, the yellow cube in the contact_system_feature example). However, I'm not sure how to proceed.

Above you mentioned this
I think, in the future:

* The force can be provided as a specific attribute, like position and transform (for simplicity)

Is something like this possible now?

Or should I use a ContactInfo class like in the example, retrieve the energies for each contact primitive type (point-halfplane, point-point, ...), then filter out which energy belongs to which vertex by using the contact topo information and in the end sum the energies up?

2. I saw that the ContactSystemFeature has a contact_energy method which has the arguments constitution and prims. I tried something like csf.contact_energy(constitution=StableNeoHookean(), prims=Geometry()), but I get the warning [warning] Contact exporter for primitive type '#10' not found.

Could you show me how the method is supposed to be used? What should I use for the prims argument?

Originally posted by @DH-Ng in #112