[ADR] Revision of simulation model creation procedure

[Nicogene]

Background & Objectives

In the iCub Tech facility we have defined a procedure for creating the CAD of the simulation model, to be used by software such as creo2urdf for creating the URDF of the robot.

Until now, during the shrinkwrap creation phase we used the Facet solid method, because it allowed to generate quickly the meshes, and have meshes that does not have an impact on the simulation (e.g. gazebo, gz-sim).

Recently @pillai-s i and @Supermonkey-design managed to define a procedure that, starting from the "real" cad, export the meshes that are nice looking and lightweight in terms of impact in the simulation:

• Add the nice meshes for ergocub V1/V1_1/V1_2 ergocub-software#266

The idea of this study is to see if we can change our procedure in order to create a simulation model that can be used by creo2urdf for the kinematic and dynamic representation (URDF), and by the script designed by @pillai-s

Outcomes

Eventually, we will deliver a new procedure, new simulation models CAD and the required changes in creo2urdf and URDF generation pipeline

Task Breakdown

From our preliminary brainstorming, it came out that we will tackle the feat with the following incremental deliveries.

⚙ MVP-1 – ETA PI22

• Try the new shrinkwrap technique on a simple assembly of ergocub (chest + head)
• Make creo2urdf export the urdf and the steps and then export it to obj manually or w/ Silvio suggestion
• Parallelly make creo2urdf export the meshes as obj wrt the correct frame (link frame).
  • Worst case: export wrt the wrong csys and we put the transform in the urdf

cc @fiorisi @pattacini @maggia80 @salvi-mattia @traversaro