[Radiance-general] Materials Library

[Greg Ward]

Hi Randolph,

The CURET database is an impressive resource, with about 60 measured  
materials.  This was the original bidirectional texture function  
measurement work undertaken by Kristin Dana during her Ph.D.  
studies.  I believe she plans a follow-up to this, but I don't know  
the schedule.  Another good resource is the Bonn BTF database, which  
though it only offers a few surfaces (10 by my count), they are  
captured at more angles, and the data are pre-aligned, making their  
application much simpler:

	http://btf.cs.uni-bonn.de/

However, adapting BTF data to a Radiance model is something I've  
never tried, and my guess is that the memory requirements would kill  
you.  Most researchers try for some kind of PCA (principal component  
analysis) or tensor representation to reduce the memory footprint.   
For example, see:

	http://btf.cs.uni-bonn.de/documentation.html
and
	http://mrl.nyu.edu/~alex/research_index.html

How you would incorporate a general Monte Carlo sampling algorithm is  
a big question.  Bottom line, if all you want is a set of materials  
to use in Radiance, I don't think a BTF representation is the  
shortest path.

Cheers,
-Greg

> From: R Fritz <rfritz at u.washington.edu>
> Date: May 1, 2008 2:17:13 PM PDT
>
> Greg, how do you judge the difficulties of using the CUReT data to  
> start a materials library? Is this a plausible project, or is it  
> likely to run into serious problems?
>
> Randolph
>
> Ref: <http://www1.cs.columbia.edu/CAVE/software/curet/index.php>