Marcin, This is really great work and I'm thrilled this has been included in the 0.6.0 release.
I'm also very impressing with your detailed explanations and assistance - thanks! A few more comments inline... > > > hillshade is basically from demtools with simple modification to > move mean value (ie. gray value of flat land) to middle of scale > (128) by adding correction: > >> cang -= sin(alt*degreesToRadians)-0.5; > > This way grain merge will leave intensity unchanged on flat areas > and mean intensity of map will be similar to one before shading. > Here is version I modified and used: > http://marcom.homeip.net/ump-www/demtools.tgz > Will be great to work on integration of some of the dem tools into mapnik (and color ramps/gradients!) I guess we would benefit from a trac ticket for discussing that, so I've stubbed one here: http://trac.mapnik.org/ticket/290 (correct the name if needed) > For areas bigger then Poland (are there bigger Countries then > Poland? ;) ) problem could be aligning separate rasters. I use one > big tiff (200MB) and gdal should allow much bigger files, but I'm > not sure if mapnik does. Mapnik currently does not support using GDAL overviews, so that may help with larger files: http://trac.mapnik.org/ticket/54 > > BTW. as for big tiffs, I have some problems with segmentation > faults. I believe its thread unsafe libtiff (60% of stacktraces are > there originated) on mapnik initialization step, when big geotiff is > analyzed for the first time (reading tiff headers and tags?). The > bigger tiffs, more time it takes to initialize and bigger chance for > segmentation faults. If renderd finally reads osm.xml file in each > thread, everything is fine, only parsing/loading > step(load_map(...) ) is multithread unstable. When I added 2-3s > delay between thread creations, I have almost no such problems, so I > ignored it meantime. > I think with latest(1 month ago svn) mapnik and mod_tile/renderd I > had the same problem & "solution" (delayed thread creation). Anyway > for day to day generating Poland I still use self-patched > mapnik-0.5.1, and quite old mod_tile apache module. > Interesting. Marcin, could you post details of this to a trac ticket? > Regards, > Marcin Rudowski Thanks! Dane _______________________________________________ Mapnik-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/mapnik-users
