[Radiance-general] Carsten Bauer marble cal file

[Carsten Bauer]

Hi Christiano,

its interesting to read that there is at least one person out there who
actually uses some of the stuff I've published on my site :-)

Concerning the pattern files, I think I cannot repeat it often enough
that they where made in an 'experimental' phase, when I started to get
aquainted with the radiance functional language.
So they are everything else but well worked out (this applies
unfortunately also to editing and handling), and they are not supported
by me in this form anymore.

To answer your two questions:

color:
In many pattern files (not only in marble) the color pattern is produced
with a 'color map' and random noise functions. Means, a random noise
function gives you a value between 0 and 1 (or -1 and 1),and dependent
on that a color is drawn / interpolated from a handful of values.

Often I use 5 color-maps, so you have 4 'division' values, between 0 and
1 (the fifth is always 1.0, so it is left out), and of course a color
rgb tripel for each division)
Changing the color of a pattern thus means the tedious job of changing
all the 5 color values. As a first start, simply leave the division
values as the are (i.e. arg 1,5,9,13) and just change the color tripels.
As an additional awkwardness, some patterns are set up as a mixture of
two layers, so you have to do this color-editing twice, once for each
layer..

tiles:
The problem with the whole pattern file business is that you need lots
of calculations files for each different pattern or variant of a it,
and, well, that small collection I've produced covers only a few cases.
In the tiles/no tiles case, however, there is a trick:
just make the tile x and y step (arg(40) and arg(41) for the marble
pattern) very large, larger than the object made out of that material,
(and maybe use a translation transformation also),
so that no tile grouts appear on your object.

Hope this helps
-Carsten




-- 
---------------------------------------------------------

"Der Deckel muß zugehen."    (P.Kölsch)

---------------------------------------------------------