[Talk-us] Multipolygonizing

[Frederik Ramm]

Hi,

On 11/19/2017 11:48 PM, Douglas Hembry wrote:
> glebius believes that this approach (with the help of the reltoolbox 
> JOSM plugin) is easier and less error-prone than having multiple simple 
> closed ways (eg, a building footprint and an adjacent pedestrian area) 
> sharing a set of nodes on their adjacent boundary. . (I hope I'm 
> representing this accurately, glebius will correct me if I'm getting it 
> wrong).

He's not entirely wrong; this approach is something we have come to
expect when you have a mesh of areas, like for example county
administrative areas: One begins where the other ends, and allowing each
to have its own "way" connecting the nodes would only increase the
amount of data and complicate editing.

However, when it comes to very small areas, like adjacent buildings or
landuse areas that only share a handful of nodes, introducing a relation
seems an unnecessary complexity.

It is most often mappers with an IT background and an unwillingness, or
even inability, to accept that there can be more than one way to do it
right - they tend to follow the "everything is a multipolygon" approach.
I've occasionally had to forcibly convince them to re-think that
approach because they were essentially turning their home turf into a
creative multipolygon landscape that nobody else dared edit. This is
IMHO the foremost reason against this "multipoligonism" - you're making
things harder to edit for others.

(Another frequent hobby of multipolygon fans is combining several
disjunct areas, say three landuse=farmland areas, into one multipolygon,
because this "saves" space, since landuse=farmland then only needs to be
tagged once not three times. IMHO this is only acceptable if the three
areas have more in common than being farmland; for example if the three
areas together share a local name or so.)

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"