Use the Convert Tets SOP to build a 2D polygonal surface around a tetrahedral solid.

If you write out the simulation to disk, write the tetrahedral geometry, not the surfaced geometry. The topology and point numbers of the surfaced geometry will change as the object fractures. If you want to add debris/dust, you probably want stable point numbers to emit from.

Always surface the geometry before rendering.

If have deforming geometry and issues with texture maps, use a cloth capture.