Le mardi 30 juin 2015 19:05:58, Ruth Simm a écrit : > Hm. Well the prj is 3857 ...but I reprojected it from 4326....would - > > I did run this on one tile - came out fine: > gdaldem hillshade DCM_N00E116.tif hillshade_test.tif -compute_edges -z 5 -s > 111120 -az 90 but this returned the same result on the global file: > > gdaldem hillshade -of GTiff infile_3857.tif hillshade.tif -compute_edges -z > 5 -s 111120 -az 90
For EPSG:3857, you shouldn't add -s 111120 as the horizontal units are already meters. > > > > > > On Tuesday, June 30, 2015 2:41 AM, Even Rouault > <[email protected]> wrote: > > > #yiv0977550860 p, #yiv0977550860 li {white-space:pre-wrap;}Le mardi 30 > juin 2015 01:20:13, Ruth Simm a écrit :> I ran this command on a > completely NORMAL (but large) global .tiff with a> few tiles missing - but > nothing else suspicious - and after 40 minutes it> returned a dud file > with '181' being the only value. Has this ever> happened to anyone > before?> gdaldem hillshade -of GTiff infile.tif hillshd.tifRuth,I guess > this might be an issue with the ratio of vertical units to > horizontal.http://gdal.org/gdaldem.html#gdaldem_hillshade:-s scale:ratio > of vertical units to horizontal. If the horizontal unit of the source DEM > is degrees (e.g Lat/Long WGS84 projection), you can use scale=111120 if > the vertical units are meters (or scale=370400 if they are in feet) I'd > suggest you experiment a bit on a subwindow of your big raster or a > subsampled version of it first.Even-- Spatialys - Geospatial professional > serviceshttp://www.spatialys.com -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
