> it doesn't seam as that damn advanced, with things like the boolean
> mental ray shader,which can make non-polygonal booleans at rendertime...

Hi ELF - well, a lot of times a boolean is more useful at modeling time than only rendering time, because there are a lot of different additional operations that you might want to apply to the intersection curve, for example rounding it with a fillet, or using it to construct additional shapes by sweeping along it, etc...

With a render-time boolean, you can only get a basic sharp-edged boolean cut and that's it. So that is a lot more limited in terms of model construction options.

- Michael