[GRASSLIST:2398] Re: Sun illuminated bathymetry

[Markus Neteler]

On Wed, Sep 05, 2001 at 11:20:12AM +1000, Gordon Keith wrote:
> I have a digital terrain model derived from bathymetry data which I
> have imported into grass.
> 
> I would like to be able to generate and view a sun-illuminated view of
> the data. Most bathymetry handling packages have this capability and
> you normally specify the direction you want the illumination to come
> from and the degree of vertical exageration required.
> 
> I'm looking for this in grass and haven't found it yet.
> 
> I tried using r.sunmask, it reached 24% after over 24 hours CPU and 1GB 
> memory then sometime over the next night it segfaulted on me.

Just a comment here:

r.sunmask is intended to calculate *shadows*, not illuminated views.
For the next release it should be stable (but still very slow for
floating point DEMs).

shade.rel.sh will be your friend.

Markus Neteler