Hi Henning, yes, that matches my findings. So far I found a small difference in the encoding of plateau lenghts but even when I changed my code to match that of BuildDEMFile I did not see an improvement. I am now trying to find out why BuildDEMFile sometimes interpolates a different height value. The values differ by a few cm and thus sometimes mkgmap rounds down while BuildDEMFile rounds up (or vice versa). I am pretty sure that this is not a problem but it makes it nearly impossible to compare the resulting bit streams. Just a matter of time ... Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Henning Scholland <osm@hscholland.de> Gesendet: Donnerstag, 21. Dezember 2017 00:59:38 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: Re: [mkgmap-dev] r4006: 1st alpha version to write DEM data Hi Gerd, just a brief feedback: Overall it seems to be fine. In MapSource and Basecamp most of the DEM-Data is displayed. But there a many squares completely empty (I guess not read at all by Garmin). Of these tiles a lot are along the coast and nearby lake-area. Maybe this is related to large areas with no changing elevation. But also there are some coast-tiles working well. If you need additional information, please let me know. Bye Henning On 21.12.2017 00:36, Gerd Petermann wrote:
Hi Henning,
please try with r4008 which implements that and also interpolation of hgt values. There seems to be a major bug somewhere in the encoder, sometimes MapSource displays only parts of the map and relief looks wrong. I did not yet find out where exactly the problem is. I tried to compare the results from mkgmp with those from BuildDEMFile. It seems that mkgmap sometimes calculates different positions because of rounding differences. I tried to do most calculations with integers while BuildDEMFile uses doubles. Will try again tomorrow.
Gerd
________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Henning Scholland <osm@hscholland.de> Gesendet: Mittwoch, 20. Dezember 2017 17:06:25 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: Re: [mkgmap-dev] r4006: 1st alpha version to write DEM data
Hi Gerd, it's a great news. I wanted to try it on my map of China. But unfortunately failed because of missing files in the sea area between Korea and Japan. Maybe it's a good 1st approach to interpret a missing file as an area with 0 elevation.
Anyway, thanks for all the research work on DEM!!!
Bye, Henning _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
_______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev