Wasn't it marabou who wrote:
>>parts of code follow (read from buttom to top):
As I said earlier, you need to specify a sensible max_trace count, or
use all_intersections, in any isosurface that's involved in CSG
operations (like your "difference").
The default max_trace is too low for the CSG.
--
Mike (why does nobody ever listen to me) Williams
