Convert Tets generates the oriented surface of a tetrahedron structure by analyzing which tetrahedra share a triangle surface. Polygons are created for the triangle surfaces of tetrahedra that are not shared. These polygons are then oriented so the normals point away from the vertex of the tetrahedra not a part of the triangle.
Use this SOP in order to create a surface that is able to be rendered from tetrahedra.
Build Polygon Soups
Instead of creating separate polygon primitives, create polygon soup primitives.