I have hypsometric model of relief, and I need to visualize shadows. I was suggested to use GRASS command r.sunmask, so I tried to set time values and run command, but it gives me an error
"ERROR: Neither sun position nor east/north, date/time/timezone definition are complete"
So then I tried to put values in Position tab, which I founded by SOLPOS Calculator (http://www.nrel.gov/midc/solpos/solpos.html)
r.sunmask elevation=model@PLANINA output=model_sunmask year=2011 month=1 day=15 hour=9 timezone=1 east=45.909361 north=15.965538
But it didn't work out, too, it says "Calculating shadows from DEM..." but nothing's going on for hours of waiting. So I ask if that command works at all in GRASS, or I'm doing something wrong?
You can suggest some other application for same thing, except ArcGIS applications. Thank you.