I did a simple mesh of twisted yarn, I am supposed to use this mesh for FEM simulation in SOFA software. In order to be being able to deform the mesh, I must have a discrete version of its volume which is VTK mesh.
I am using GMSH, and I got the following error: the mesh doesn't have a Tetrahedric topology: this means that I have a problem in the mesh at blender, I don't know what is the problem, here the files:
Here is the OBJ file:https://gofile.io/?c=X0Hm6U
Here the VTK file: https://gofile.io/?c=gFZfJ0
I would be grateful for help in figuring out the mistake in the mesh.
Thanks in advance.