3ds Max :: Rendering Two Sided Materials?

I am attempting to create a short animation of two asteroids colliding and exploding. I created two spheres with noise and used a bomb to break them apart and added a sphere gizmo for the explosion. Everything is working great, however when I render, the normals are an issue. My asteroid pieces are see though on one side despite checking two-sided in the standard material parameters and checking force two sided on the render options panel.