[Tagging] Mapping nonexistent paths

[Sinus Pi]

czw., 25.03.2021, 01:27 użytkownik Niels Elgaard Larsen <elgaard at agol.dk>
napisał:

> Sinus Pi:
> > Niels wrote:
> >
> >> There is an obvious pedestrian route from the Blåbær Alle area to the
> > Solbær Alle area.
> >
> > This is an obvious case for line-of-sight routing, implemented in some
> > routers, AFAIK.
>
> Which routers are those?
> Can I use them on my phones to navigate?
> It certainly does not work in ORSM, Grasshopper or Osmand.
>
>
> Besides, line-of-sight is not enough, you might have to go around corners
> and avoid
> obstacles.
>
> We need to provide a topology that can be used by OSM users using
> available routers.
>

Line of sight is (or should be?) simply an optimization of
all-corners-to-all routing, surely rather obvious in graph routing.

Wiki on area:highway -
> However, as of 2019, OpenTripPlanner
<https://wiki.openstreetmap.org/wiki/OpenTripPlanner> is the only OSM-based
router that supports routing over areas. It does so by computing a
"visibility graph" over the area.

Frankly, it seems either lazy of routers not to perform this, or they
weren't really worked on since the advent of routable areas. Creating a
sub-graph of all connections within an area and caching some of them as
usable links between points shared with other highways is quite simple and
potentially faster than routing along edges. But in the end it'll still be
just bouncing off corner nodes, and might not represent what a real person
would do. Hence the possible need for virtual guidelines, which I
wholeheartedly support.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/tagging/attachments/20210325/b37847cd/attachment.htm>