Hi Gerd Patch attached that, where possible, keeps ~straight roads unchanged and widens the sharp angle on the other road. This should fix the particular example and generally be better, although it is difficult to test. I try and note where I get incorrect turn instructions and later work out why and, since the arcHeading_v2.patch in Oct 2020 I haven't found any that are fixable; I couldn't find a solution where the major road continues at an angle and the minor side road continues straight on. Ticker On Mon, 2024-08-05 at 19:14 +0100, Ticker Berkin wrote:
Hi Gerd
I presume you are just changing SHARP_DEGREES, leaving COMPACT_DIR_DEGREES alone.
In this example the arcs on either side of the sharp angle have the same priority (class/speed) so there isn't an obvious one to adjust so the logic adjusts both.
Also in this example, and very common, is a side turn off a basically straight road and the proportions that each arc is adjusted isn't ideal in that the straight road is bent slightly more than the side turn is adjusted.
This could be spotted as a special case: when there are 3 arcs and the available angle on one side or the other (initial value of deltaPred or deltaNext) is close to 180 degrees then just the other side should be adjusted. Maybe the 3 arcs doesn't really matter as long as there is sufficient space to adjust the other side.
I'll do some experiments.
Ticker
On Mon, 2024-08-05 at 08:55 +0000, Gerd Petermann wrote:
Hi Ticker,
thanks, I didn't test much, but with a value of 22.5 (or 23) the problem disappeared. It also disappears with --x-ignore-sharp-angles. Downgrade is that the NOD size increases a bit, but I think that is better than wrong turn instructions.
Let me know if you cannot reproduce and I'll create a more complete description reg. the options in use.
ciao, Gerd
________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Ticker Berkin <rwb-mkgmap@jagit.co.uk> Gesendet: Montag, 5. August 2024 10:42 An: Development list for mkgmap Betreff: Re: [mkgmap-dev] Problem in AngleFixer?
Hi Gerd
I'll need to look carefully at this code again.
ISTR the 46 degrees was to stop arcs getting into the same compact segment when they shouldn't. My changes stopped a lot of incorrect turn instructions but maybe there is still scope for the algorithm to look for the same road entered and exiting in a straight line and try to preserve this by adjust other roads more.
Noticed that, in the example, these are bike routes and it looks like the algo ignores these.
Ticker
On Mon, 2024-08-05 at 06:37 +0000, Gerd Petermann wrote:
> > > Hi all, > > > > > > in a private email Thorsten Kukuk contacted me about wrong > > > turn > > > instructions > > > a > > > sharp angles. > > > An example is the node https://www.osm.org/node/27550903 > > > > > > A route coming from South that follows the way > > > https://www.osm.org/way/36138336 at this junction should NOT > > > produce a > > > turn > > > instruction. > > > A route that turns left SHOULD produce a turn instruction. > > > With current mkgmap it's vice versa and thus not OK. > > > > > > I thnk the current code in AngleFixer.java is too agressive as > > > it tries > > > to > > > enlarge the angles so that a compact format can be used to > > > write > > > the > > > heading values of the arcs at the mentioned node. It does this > > > by > > > changing > > > the > > > heading values of both arcs with go to the north. > > > > > > @Ticker: The code was introduced with your > > > arcHeading_v2.patch, > > > but > > > maybe it > > > existed before. > > > Can you explain why the constant AngleChecker.SHARP_DEGREES is > > > set to > > > 46° > > > instead of maybe 22.5° ? > > > > > > Gerd > > > _______________________________________________ > > > mkgmap-dev mailing list > > > mkgmap-dev@lists.mkgmap.org.uk > > > https://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
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