[Radiance-general] Re: Related (maybe) to "Strange Glowing Buildings"

[Greg Ward]

Surface normals are definitely a hack, but a worthwhile one in many  
cases.  Radiance does it's level best to deal with perturbed normals in  
the ambient calculation and elsewhere.  Results aren't always perfect,  
but hey -- it's Radiance, not Renderman!

To remove surface normal interpolation from a .OBJ file (converted with  
obj2rad), apply the -f option.  To eliminate them from 3DS files when  
you used 3ds2mgf, you can use the little-known mgfilt program after  
3ds2mgf and before mgf2rad (there really should be a -f option added to  
mgf2rad, I suppose).  Here's an example:

	3ds2mgf building.3ds
	mgfilt  
'#,c,cct,cone,cmix,cspec,cxy,cyl,ed,f,ies,ir,m,o,p,prism,rd,ring,rs,side 
s,sph,td,torus,ts,v,xf,fh' building.mgf | mgf2rad > building.rad

A nasty command just to remove surface normals, but it beats writing a  
script (for most people).

-Greg