[Radiance-general] colorpict and materials

[Lars O. Grobe]

Hi!

I have a question regarding the proper use of colorpicts.

I have "calibrated" pics of materials (using macbethcal) that I used to 
get the rgb-values for material definitions. These samples have 
typically dimensions of about 30 x 20 cm (similar to the Macbeth 
colorchecker). I rendered using the materials colors obtained from 
these samples.

Now I want to map pictures onto the surfaces. I still want to use the 
color as obtained from the sample. But the mapped picture is usually 
much larger than the sample. So I would need a way to bring the average 
color of the picture to the (average) color of the calibrated sample. 
Is there a way to do that with Radiance's tools? I could use these 
mappings on a clear white (.9 .9 .9) surface than, right?

Is there a way to use the pic only as variation of the color? E.g. 
converting from radiance pic to a file that could be used by 
brightdata? I could use the color from the calibrated (small) sample 
than, and the big pattern only to map some structure.

The way I used so far: applying normpat to a grayscale pattern, and 
mapping that onto the surface which has the color measured from the 
sample. Similar to using brightdata, and not able to reflect the color 
variation.

Thanks, CU Lars.
--
Lars O. Grobe, grobe at gmx.net, ++90-212-2458330

Kardesler Apartment, Turnacibasi Sokak 28
Galatasaray - Beyoglu, 34433 Istanbul