[GRASS-user] Shadow maps...

[Markus Neteler]

On Jan 9, 2008 12:28 AM, Jonathan Greenberg <greenberg at ucdavis.edu> wrote:
> Quick question: is there a functional difference between the shadow
> algorithm found in r.sun and r.sunmask?

Yes.

> I'd like to use a ray-trace
> based shadowing algorithm -- if r.sunmask does this (the documentation
> doesn't indicate whether or not it does), it seems that would be a
> faster alternative to running the entire r.sun algorithm.

r.sunmask is WAY slower.

r.sun -s is fast and includes also earth curvature.

Additionally, we have r.horizon/r.sun2 which might be of interest:
 http://trac.osgeo.org/grass/browser/grass-addons/r.sun_horizon
I assume that r.sun2 is again faster since r.horizon was separated
out and needs to be run only one time.

Markus