I guess it all depends on what you're willing to give up. Openscad doesn't do lighting, but the debug operators combined with the intersection might be good enough, if you don't mind all your lights having a red hue: [the 'color' operator doesn't seem to affect this debug operator] If you want a better modelling of lighting and/or colouring transparent cones, I'd suggest blender: http://wiki.blender.org/index.php/Doc:2.4/Manual/Lighting/Lamps/Spot -- View this message in context: http://forum.openscad.org/ies-volume-visualization-tp12522p12524.html Sent from the OpenSCAD mailing list archive at Nabble.com.