trad.tar.Z @ 138719 bytes,
	A TCL/TK interface shell for the Radiance Raytracer.
This is *not* a modeler,  but is a great GUI for radiance 
operations. You will need a working Tcl7.3 and Tk3.6, but that
is available in binaries all around.. And of course, the 
Radiance raytracing package itself.