I've been rendering for about 7-8 years (and still prefer to work in AutoCAD 2000 in this instance), but I still haven't figured out to either create a shaped light source, or to declare a solid as a light source (if either of these is possible). I'm getting into rendering office buildings in conjunction with specialty warehousing we design, and a ceiling grid (and the corresponding light fixtures) would make a great touch.

Any help on this one would be appreciated.