Don't all point and laugh, I know this looks crap :o( It's just a quick preliminary render to demonstrate the problem I'm having. Normally, if I'm boolean-ing, I use terrains, and everything is fine. At the moment I'm playing with ideas for roundabouts, and one of the ideas was to have a mound with cuts through the centre, all asymmetrical so there isn't a line of sight through, with a mysterious glow coming from the centre (I visit the Bryce forum too much!). Thought there'd be no prob, but lo and behold, when I try to cut through the mound using negative shapes, only the first one works. I've tried grouping all the shapes, then making the group negative, that doesn't work. I've tried adding the negative shapes one at a time to the previously-formed group, that doesn't work. Am I missing something really obvious? This cut-out I've made by doing an altitude render of the the assembled shapes, and using it as a terrain, but that's a ridiculous way to have to go about it. Advice?