floating point grass rasters and mapserver

[Neil Best]

On Tue, 11 Oct 2005 09:18:06 -0500, William Kyngesburye
<woklist at KYNGCHAOS.COM> wrote:

>I thought I heard that you could use a grass image group in
>mapserver.  Have 3 bands in the group with 0-255 each for RGB.  Never
>got around to trying it.  Since MapServer doesn't doesn't use the
>GRASS color info, I guess it would only work for image-type data
>directly, you would have to manually transform something like
>elevation data into 3 bands.
>
>

Hello, all.  I am trying to understand if/how MapServer can take advantage
of GDAL's abillity to read GRASS groups per
http://www.gdal.org/frmt_grass.html  Is it possible to display RGB
composites as William surmises above?  Do the GRASS layers have to be 0-255
integers strictly or will a float work as long as it has 256 levels?  How do
the PROCESSING directives play into this?  It's not clear to me which, if
any, of the directives are relevant to GRASS layers -- maybe there is
another page somewhere with more details beyond the "Raster Data Access"
page.  BTW, I believe MS _does_ now use the GRASS color tables.  

How much interest is out there for these features?  For us, it would be a
great boon to be able to point directly at native GRASS layers and not have
to export them out and double our archive maintenance overhead.

Neil