[Radiance-general] Mesh smoothing

[Georg Mischler]

Russell Maunder wrote:

> I have a question about smoothing. If you add the -s switch in gensurf you
> can get a smooth shaded surface. Is there any way I can insert this smoothing
> to a surface that I have imported from AutoCAD? I do not want to increase the
> polygon count but i do want to smooth out the faceted glare on the surface.

The "correct" solution would check if any normals are defined
already in Autocad/DXF, and use those to generate texfunc
modifiers similar to the ones gensurf creates from that
information. I have some unproven code to add this feature to
Radout and dxf2rad, but have never had the time to look into it
more deeply, in order to understand how and if it actually works.

Theoretically, you could also try to analyze the polygons in a
radiance scene file, find out which ones have common edges, and
if the difference between their normals is below a certain
margin, apply a texfunc to them, smoothing out that difference.
Not very elegant, but possible. Note that Rayfront removes
all modifiers when it imports geometry data, so that you will
have to edit the imported files in place.

If anyone can point me to really solid and understandable
information about how to work with the "barycentric coordinates"
that gensurf uses for this purpose, then I'll try to get it to
work with the next releases of Radout and dxf2rad.


> On a side note I am also looking at modelling light redirection systems
> (horizantal/vertical glazing) and refractive systems. I have looked at some
> of the designs on www.schorsch.com and attempted to model them using AutoCAD
> or a gen program then assigning a dielectric material. Does any else have
> experience with creating these and would it be possible to use a different
> modifier? I am looking for the most accurate calculation.

Those illustrations are on my site because I'm currently working
on a plug-in to Rayfront that will allow a full and correct
simulation of (most of) those systems. Simulating them with
Radiance alone is very exhaustive, and likely inaccurate in most
cases. Radiance is not designed to handle multiple mirror
reflections in tight spaces effectively. Of course, this doesn't
have to keep you from trying, just that you shouldn't put too
much trust into the results.


-schorsch

PS: Didn't forget your other mail...

-- 
Georg Mischler  --  simulations developer  --  schorsch at schorsch.com
+schorsch.com+  --  lighting design tools  --  http://www.schorsch.com/