(My VFX) TOS - The Doomsday Machine WIP4

I still need to add the little rock that comes apart when it hits the Constellations hull. I've been trying to figure out how to create the chunks, I've used some free scripts (like  Fracture Voronoi), but they make the inside surface smooth shards and they don't look right... how can I make chunks that fit together, but aren't smooth surfaced on the inside.

The last shot isn't remotely finished... I'm thinking of making the DDM hull look more blue than purple.

See video here: www.youtube.com/watch?v=FKavQ_…