[Radiance-general] Strange Glowing Buildings... Ack.

[Jeffrey McGrew]

Hello all,

	I'm having a problem with my buildings I'm exporting out of Revit, 
and am trying to figure out where the problem is coming from. I'm 
hoping someone out there can help me out a little with this issue, for 
I don't understand enough about Radiance to really know why this is 
happening, and can only guess at why.

	Just for the record, if I make a model from scratch using textfiles I 
don't have any of these problems. Additionally, the problem crops up 
whether I'm using Radiance on Cygwin, OS X, or Mandrake Linux, so it's 
obviously something I'm doing or a problem with the models coming out 
of Revit.

	My problem is the fact that my buildings all appear as if they are 
'glowing'. Things like the site, and any Radiance-created objects or 
instances render correctly, however the buildings, especial the large 
flat surfaces such as walls and such, almost appear to be glowing 
because they seem to be bouncing so much light off of them, almost as 
if they are made of perfect white gypsum in broad daylight.

	The material definitions for the walls aren't set too high, the 
colors are typically .8 or .7 for the RGB values, and the roughness is 
usually set to .15 or so- both values that don't seem too far off. 
Also the Exposure for the scene tends to be about right for other 
Exterior Radiance scenes and the sun is a simple Gensky straight from 
the first tutorial file. Yet however the building will be bouncing 
almost twice the light off of it of anything else in the scene!

	The way I get my models from Revit to Radiance might be the key to 
why the models are behaving the way they are. I export the models to a 
DWG file that I then bring into AutoCAD and then use RADOUT to produce 
the models. However there are issues with this, for RADOUT or TORAD 
don't work quite right in the latest version of AutoCAD that I'm 
using. I've tried to use dxf2rad, but it always seems to choke on the 
models. They are very large, very complex, and have many surfaces. So 
I'm wondering if that's the root of my problem; is something in the 
export process possibly causing this?

Thanks for your time,

Jeffrey McGrew