Hi OJM I use Truespace 4 If I have understood your question correctly what you need to do is use the Boolean tool to union the parts together. This will eliminate all the surplus mesh inside the object. Also, generally try to keep the polygon count as low as possible. If you are using NURBS operations this can run exteremly high. Whilst I'm here I'll recommend John Wind's Compose utility which will convert between COB and OBJ format. It will also perform grouping operations. If I can be of further help I'm happy for you to email me at pcooke@mis.net or view my pages at http://www.users.globalnet.co.uk/~pcooke/graphics/examples.htm