SOFAv21.12 : TetrahedronFEMForceField(forcefield)], apparent missing tetrahedric topology

[cdelor02]

Hello all. In reconfiguring the CableGripper example from the SoftRobots plugin to use my own finger design, I am encountering this error: [ERROR] [TetrahedronFEMForceField(forcefield)] object must have a tetrahedric topology. The component is inactivated. To remove this error message please add a tetrahedric topology component to your scene. My understanding is that my .msh file/my files must be generated in a specific way to be compatible with the FEM procedures being done in my Python script. I have done what I believe is correct by referencing this post to the forum about needing a tetrahedral topology available, as commented by @hugtalbot. I have generated what I think is a .msh that would satisfy this but I am still encountering this error and it is not clear as to where in my SofaPython script this is happening. If anyone has an idea as to where the issue is originating as well as how to actually produce a tetrahedral mesh, that would be greatly appreciated. Thank you. I have attached a .zip of all my files, including my py3scn script and the finger model files I am using. Certain files are not included, however they should be available from the SOFA basis (SoftRobots, namely).

myactuator_sim_files.zip

[hugtalbot]

Hey @cdelor02
This error has the same explanation than your other post here. The TetrahedronFEMForceField is a SOFA component expecting to have a tetrahedric topology, e.g. your mesh file must include tetrahedra discretizing the space of your object. Here your topology may only include triangles but no tetra.

The way the simulation community usually does things is to generate a volumetric mesh (including here tetrahedra) using a mesh tool.

In SOFA, we have something very basic (which I discourage to use on the long-term) to generate a tetra topology from a triangle mesh: the MeshTetraStuffing (example available here)

Hope this helps