[Radiance-general] materials in radiance software

[Axel Jacobs]

Hi Imene

> Do you khow any websites that gives many examples of materials defined by their roughness and specularity fractions and RGB reflectance (examples carpet, mdf, aluminium, marble....) ? how can we choose the RGB colors in radiance when we have multicolor mat?rial like carpet?

Somewhere within the Radiance src tree, there is a materials file of
typical building materials, including spec and rough. This has been
integrated in the Colour Picker for Radiance which you can find here:
http://www.jaloxa.eu/resources/radiance/colour_picker.shtml
Go Chooser > Building Materials

Multi-coloured materials are trickier and require some cal file. This
can be quite complicated to work out. Carsten Bauer developed some
mindbogglingly complicated examples for granit and other materials.
They were somewhere on his Radzilla web site (which is no longer
actively developed):
http://www.cb-d.de/radzilla.html

Unfortunately, all Radzilla download have been removed because the
code was getting too old. I might still have the Radzilla materials on
my hard disk at home. I shall try to get permission from Carsten and
send them to you, if you like. Please contact me off-list if you are
interested.

Determining spec and rough to any degree of accuracy is nighly
impossible. Your best bet is to do some test renders and compare them
to physical samples of the materials that you are trying to match.

Regards

Axel