Create skeleton from existing manipulator files (skel vs. manually)

Hi everyone :nerd_face:

I got a little confused on how to properly import an existing geometry of my manipulator.

Current situation:
I have got a complete description of a given manipulator:

  • kinematics
  • mass and inertia information for each body node
  • stiffness and damping properties of the joints
  • .obj files for visualization

I need to model the joints as ball joints, so importing an URDF file does not work to my understanding, since URDF only supports revolute joints up to now.

Open question:
What is the easiest way to create a full model of my manipulator?

Possible approaches:
From my point of view, I see two possible ways:

  • manually parsing through my manipulator description and creating joints and body nodes in C++.
    Open question for me here is: How to create simple body node and I load the existing .obj file manually to these body nodes? I couln’t figure that out from the tutorials. This approach also seems to be very labor-intensive…

  • creating an .skel file for my manipulator. As your documentation indicates, skel files support ball joints and seem to be implemented pretty much straight forward. Unfortunately, I have no clue how to include .obj files either, the examples only use boxes etc. for geometry descriptions…

Thank you very much in advance and best regards


I figured it out: I imported the URDF model to import the kinematics and geometry and replaced the revolute joints with ball joints.