[mkgmap-dev] Bad routing on eTrex and MapSource

Sat Jul 11 17:05:51 BST 2020

Hi Ticker,

I still have no clue where to change something :(
 Routing works fine for pedestrian mode and all the shown values like length or directions look correct, so it seems that the encoded values are interpreted as expected. I've also tried things like mirroring all the data on the vertical axis. Results were exactly the same after I also changed drive-on=left to drive-on=right.

Problem disappears when the length of the arc between  node 712553226 and node 5691769367 is a bit longer, e.g. 33m instead of ~30m so that it is encoded with the next higher byte value. When I change the geometry so that the arc is even shorter it doesn't seem to help.
It really looks like Garmin doesn't like to make to left turns within less than ~32 m when shortest route is selected and traffic mode is not pedestrian.

Gerd

________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
Gesendet: Samstag, 11. Juli 2020 13:20
An: Development list for mkgmap
Betreff: Re: [mkgmap-dev] Bad routing on eTrex and MapSource

Wow - that is a simplification. I was initially confused because both
BaseCamp and Mapsource show the old, full map, despite it having been
renamed, but show the routes between the 9 nodes in your minimal test
map.

Ticker

On Fri, 2020-07-10 at 11:13 +0000, Gerd Petermann wrote:
> Hi Ticker,
>
> it seems to be related to the encoding of the heading / bearing data.
> I've reduced the test case to a few roads (see attached file) which
> still show the problem.
> When I rotate this small set of data a little bit the problem
> disappears.
>
> Will continue later...
>
> Gerd
>
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von Gerd Petermann <gpetermann_muenchen at hotmail.com>
> Gesendet: Freitag, 10. Juli 2020 09:28
> An: Development list for mkgmap
> Betreff: Re: [mkgmap-dev] Bad routing on eTrex and MapSource
>
> Hi Ticker,
>
> OK, I've updated Basecamp to 4.7.2 now. When I change the car profile
> to "shortest way" I also see the long detour, so yes, that makes it
> more likely that mkgmap writes wrong data. Not sure if I tested this
> wtih 4.7.1
>
> I'll try to find the trigger for this.
>
> Gerd
>
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
> Gesendet: Freitag, 10. Juli 2020 09:08
> An: Development list for mkgmap
> Betreff: Re: [mkgmap-dev] Bad routing on eTrex and MapSource
>
> Hi Gerd
>
> There is something very wrong here with the routing here.
>
> Apart from this example, I've never experienced the device taking a
> long detour to avoid right turns. Testing with BaseCamp and shortest
> distance on MapSource, the route goes the wrong way and makes a u
> -turn
> - see attached BaseCamp trace - do you see this behaviour.
>
> What could be a similar problem I discovered the other day was a
> secondary road with a right turn into a alley to a car park. The
> device
> and MapSource wanted to turn into the alley, do a u-turn, then turn
> right out of the alley and continue on the road. BaseCamp took a 5 km
> detour to avoid going past the alley.
>
> I've also attached my modified test script.
>
> Ticker
>
> On Thu, 2020-07-09 at 15:40 +0000, Gerd Petermann wrote:
> > Hi Ticker,
> >
> > I also don't understand the results in MapSource but I could not
> > find
> > anything wrong in the img data. I also didn't see anything wrong in
> > the route directions. What value looks suspicious to you?
> > My current thinking is that you found an error in the Garmin
> > software. I think it overweighs the two right turns (in a drive-on
> > -left country)
> >
> > Gerd
> >
> > ________________________________________
> > Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> > von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
> > Gesendet: Donnerstag, 9. Juli 2020 17:12
> > An: Development list for mkgmap
> > Betreff: Re: [mkgmap-dev] Bad routing on eTrex and MapSource
> >
> > Yes, setting drive on left changes the behaviour back to as
> > described
> > at 12:03 (but it don't why)
> >
> > Ticker
> >
> >
> > On Thu, 2020-07-09 at 14:32 +0000, Gerd Petermann wrote:
> > > Hi Ticker,
> > >
> > > without bounds the program probably doesn't set the drive-on-left
> > > flag, so you should set option --drive-on=left to get similar
> > > results.
> > >
> > > Gerd
> >
> > _______________________________________________
> > mkgmap-dev mailing list
> > mkgmap-dev at lists.mkgmap.org.uk
> > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
> > _______________________________________________
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> > mkgmap-dev at lists.mkgmap.org.uk
> > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
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