Well, I did it. I managed to get two non trivial objects to form a boolean union. Admitedly, there are a few jagged edges and a few holes, but hey, I can stand a bit of manual editing of vertices when absolutly necessary. For some background read the "Carrara: convert two meshes to a single mesh?" thread. Basically, I've been attempting to make a mesh from P4 female hip&abdomen object and a skirt shaped object, to make a customised skirt. Eventually, I reduced the complexity of the skirt object (read: remade it) and deleted as much of the hip object as I could whilst retaining the necessary parts to obtain the shape I wanted. Then the boolean union worked (mostly) without giving the 'rendering failed' message. Now, a chance for you techies to redeem yourselves by answering these questions. Did this work because I reduced the distance between the various edges to a point where Carrara could cope? Or, did I just reduce the total number of vertices to a point where Carrara could cope? Would increasing the amount of RAM available (currently 128MB, 400MHz PC) make a big difference to the complexity of the boolean operations Carrara could perform? Or, is there a fundamental limit with the present boolean operations subroutines? I know that increasing the virtual memory available to over 6 Gigs had no effect whatsoever. I look forward to some interesting and hopefully encouraging answers. IsaacNewton