Modify

Opened 7 years ago

Last modified 10 months ago

#9534 new defect

Strange "overlapping water areas" test result

Reported by: naoliv Owned by: team
Priority: normal Milestone:
Component: Core validator Version:
Keywords: Cc:

Description

Validate the attached example file and see that there is a warning about "overlapping water areas".
I can't see anything overlapping there.

Attachments (3)

overlapping.osm (127.9 KB) - added by naoliv 7 years ago.
simplified_overlapping2.osm (2.0 KB) - added by mdk 7 years ago.
simplified version (6 nodes, 2 ways)
wetland_example.osm (4.8 KB) - added by mdk 7 years ago.
natural=wetland exaple with lots of warnings

Download all attachments as: .zip

Change History (17)

Changed 7 years ago by naoliv

Attachment: overlapping.osm added

Changed 7 years ago by mdk

Attachment: simplified_overlapping2.osm added

simplified version (6 nodes, 2 ways)

comment:1 Changed 7 years ago by mdk

I have striped down the example to 2 ways and 6 nodes.

Here are my findings without tracing the JOSM code:
1) There is not only a warning about "Overlapping Water Areas", but also two related other "Overlapping Areas" hints.
2) The "Overlapping Water Areas" has only to deal with natural=water. If you change it to natural=scree, only the two "Overlapping Areas" hints remain. Even if you remove all tags from the ways, the two hints appear (but you get two "Untagged ways" warnings as expected.)
3) If you imagine that the railway is a closed triangle (or you can really close it - it doesn't matter) than the water triangle is crossed by this missing railway segment.
4) If you move the water area inside or outside this railway triangle, the warning and the hints disappear.

So the overlapping area test has some general problems:
1) Normal ways (like the railway) are treated as areas, even if the are not closed and even if they have absolutely no tags!
2) Crossings of every kind of ways produce "Overlapping Areas" hints.

Last edited 7 years ago by mdk (previous) (diff)

Changed 7 years ago by mdk

Attachment: wetland_example.osm added

natural=wetland exaple with lots of warnings

comment:2 Changed 7 years ago by mdk

I have also related problems with natural=wetland areas overlapping natural=water or natural=grassland etc.

On a lake, there are normally 4 different zones:

  1. open water (natural=water)
  2. waterside reed (natural=water & natural=wetland)
  3. land side reed (natural=grassland & natural=wetland)
  4. normal land (natural=grassland)

Is the attached wetland example a good mapping for this case? Than it should not create 2 warnings and 5 hints!

comment:3 Changed 7 years ago by mdk

Btw: It would be helpful if the validator message for overlapping areas would contain both ways, not only one.

comment:4 Changed 7 years ago by simon04

In 6630/josm:

see #9534 - "Overlapping areas" validator: do not generate warnings for non-closed/non-area-style objects

comment:5 Changed 7 years ago by Don-vip

Milestone: 14.01

comment:6 in reply to:  2 Changed 7 years ago by simon04

Replying to mdk:

Is the attached wetland example a good mapping for this case? Than it should not create 2 warnings and 5 hints!

Is this a common way of mapping those zones (I've never thought of such a case)? As long as this is an "official way", I'd prefer to stick to the warnings.

comment:7 Changed 7 years ago by simon04

Owner: changed from team to naoliv
Status: newneedinfo

comment:8 Changed 7 years ago by simon04

Owner: changed from naoliv to mdk

comment:9 Changed 7 years ago by anonymous

Your question is, if this kind of mapping is "common"? For the area I'm mapping like http://www.openstreetmap.org/#map=19/47.37848/8.86184, http://www.openstreetmap.org/#map=17/47.39628/8.89572 or http://www.openstreetmap.org/#map=17/47.41359/8.90637, the answer is YES. For the rest of the world? I don't know.
In #9507 is an example with the comment ".. what is typical situation in many places".

Looking around I found some similar places:
http://www.openstreetmap.org/#map=16/53.4386/8.3033, http://www.openstreetmap.org/#map=17/47.45138/7.92963, http://www.openstreetmap.org/#map=15/47.9915/11.0025, http://www.openstreetmap.org/#map=15/47.7616/10.3875, http://www.openstreetmap.org/#map=14/48.6292/15.2022, http://www.openstreetmap.org/#map=15/54.1411/11.8894
So here I stop, because the actual slow tile rendering sucks :-)

I hope this answer your question.

comment:10 Changed 7 years ago by simon04

Milestone: 14.0114.02
Owner: changed from mdk to team
Status: needinfonew

Thank you.

I'm unsure how to best handle this special case.

comment:11 Changed 7 years ago by anonymous

There is a general problem with "transparent" areas like landuse=military, leisure=nature_reserve and natural=wetland. Is it mapping for the renderer, because renderer like Mappnik draw this areas "transparent" or is it the general nature of this areas so that they can (or should) overlay with other areas?

comment:12 Changed 7 years ago by Don-vip

Milestone: 14.02

comment:13 Changed 7 years ago by mdk

Does the fix of #10120 has any impact on this issue?

comment:14 Changed 10 months ago by skyper

What is wrong with a lake, mayby, with intermittent inside a wetland? If you map it as MP and exclude the lake from the wetland it might be wrong as if the lake disappears over the season all could be wetland. This is a different situation compared to forest + lake.

I vote for ignoring natural=water inside natural=wetland.

Modify Ticket

Change Properties
Set your email in Preferences
Action
as new The owner will remain team.
as The resolution will be set.
to The owner will be changed from team to the specified user.
The owner will change to naoliv
as duplicate The resolution will be set to duplicate.The specified ticket will be cross-referenced with this ticket
The owner will be changed from team to anonymous.

Add Comment


E-mail address and name can be saved in the Preferences.

 
Note: See TracTickets for help on using tickets.