Hi, I am trying to use the DEM/hillshading option. You can specify a path to the DEM tiles, but it seems that there is a hardcoded assumption about the naming format of the .hgt files. I want to use an existing set of .hgt files used by another application which has a slightly different naming convention - in this case just a prefix. Of course it would be possible to copy all files to a new name, but it seems rather wasteful to copy such a large amount of data just because of naming issues. So it would be very helpful to be able to not only specify a path but also a naming pattern to use, e.g. something like --dem=p:/dem/prefix_N{$lat.2}E{$lon.3}.hgt I would be willing to contribute the feature myself, but I am encountering difficulties - see separate mail. bye, Nop