1. Revit likes to model glass as a solid plate, not a flat surface. So a bit of glass is a rectangular solid, not a flat plane. So when I try to make the windows into Illum's so that they spread light into the room, I'm getting errors and problems because I think it's looking for a flat plane with the normal pointing into the building. How important is it to have the Windows be a lightsource for interior renderings? Is there some way, via Mkillum or something, that I could quickly work around this issue? I can flatten the glass in Max, but that's an extra step and one that seems to also cause issues with zero-area light surfaces.
Ugh. Yeah, programs like Revit and 3DS, et al. make glazing planes as 3D objects with six polygons. No good. Your errors and problems are definitely related to this. mkillum expects a single polygon, looking in. Not sure how you're flattening the planes, but I'll bet you're still ending up with a pair of triangular polys representing the glass plane, and who the hell knows which way they're facing. mkillum likes regular polygons. Page 577 of Rendering with Radiance has the gory details. Not sure the answer to your problem, just stating the issues.
2. When I export out of Max, I get a .OBJ and a corresponding .MTL materials file. I currently use Grep and such to pull out all the material definition names out of the RAD file I get from OBJ2RAD, and then creating the .MAT radiance material file by hand. I'd love to hear a way to take the exported .MTL file and turn it into a starting point for my .MAT (short of having to write my own tool to do so...).
If you can grep the stuff out, I'd bet you could write something to take the result(s) and generate a corresponding .mat file, with shell scripting techniques, or python or perl, or whatever.
Now, we're just designers, and looking for design feedback not hard numbers. We'd be happy with something somewhat-accurate, for if/when we need 'real numbers' we'll typically turn to a lighting designer who know how to generate accurate numbers. But I figure, heck, we're generating these models anyways, why not try to put that to better use?
Sounds like a plan. The thing is, you are closer to real numbers than most lighting designers, by having the wherewithal to tackle Radiance. Don't short-change yourself. A good model and sound parameters in Radiance beats any of the tools commonly used in lighting design, IMO.
On May 10, 2006, at 9:13 PM, Jeffrey McGrew wrote: