I have a code that creates surfaces and I export an stl using stlwrite. I was wondering if there is a way to convert the surface mesh into a volume mesh (tetra mesh). At the moment, I am re-importing the Stl and using the generatemesh function. It plots the resulting mesh and it looks nicely. However, I cant find a way to just export that mesh to Abaqus. I tried a different approach using matlab2abaqus and similar codes but nothing seems to work. I must be missing something. Can you please help me out.