[GRASS-user] GTiff export

[Przemysław Bojczuk]

Raffaele Morelli wrote:

> I got two raster files imported in Grass using r.in.gdal, one represents a
> dem, the other is a "drape". (the files originated from ArcGIS)
> I am setting up a WebGis app (apache, mapserver, php_mapscript) and need a
> tiff layer to represent elevation and have a image background to put my
> vectors/points on.

My answer would fit better on the mapserver mailing list, but oh well...

If you have what I have, i.e. a grey-shaded relief in one file and
coloured DEM in another, the best option might be displaying the relief
in the background and overlaying it with a transparent DEM
(TRANSPARENCY 50 in LAYER section). It looks pretty good and it's
actually the only decent option I could come up with. You might also
want to set IMAGETYPE PNG24 if the colours don't look good, but be
aware it enlarges the output image size significantly.

You can see the effect of the above here:
http://gis.umcs.lublin.pl/skorowidze/ (the last two layers, hipsometria
and rzezba, are the DEM and the relief respectively).

I hope that helps.