Opened 10 years ago

Closed 9 years ago

#980 closed defect (fixed)

Bridges with layer=5 appearing below bridges on lower layers

Reported by: craigermcgreger@… Owned by: steve8@…
Priority: trivial Milestone:
Component: mapnik Version:
Keywords: Cc:


I have several bridges with layer=5. According to the documentation for the "bridge" and "layer" tags on the OSM wiki, five is a valid value for the "layer" key. However, the layer 5 bridges are being rendered so that they appear below bridges that have a "layer" value of 1 through 4.

Examples of the problem:

Change History (7)

comment:1 Changed 10 years ago by tom@…

  • Owner changed from tom@… to steve8@…

I think the problem here is that the road on layer 5 is a motorway_link while the one on layer 3 is a motorway, and mapnik's ordering rules make that quite hard to handle.

It looks Steve has tried to cope with this with special styles for motorway bridges so that each layer is rendered in turn, but he only has rules for layers 0 to 4 at the moment so one needs adding for layer 5 I think.

comment:2 Changed 10 years ago by craigermcgreger@…

Perhaps the highway classification is affecting bridge layering: I just found another place with a similar issue, albeit with layer 2 bridges appearing below layer 1 bridges:

In this case, the layer 2 bridge is a "lesser" classification (primary) than the layer 1 bridges (motorways and motorway_links).

Hope this helps.

comment:3 Changed 10 years ago by ElDiabolo

I have another example which has only layers 0,1 and 2:

Note that switching to osmarender gets it displayed correctly.

comment:4 Changed 10 years ago by schuetzm@…

Here's another one involving a highway=track bridge on layer 1 and a highway=motorway without layer:

comment:5 Changed 10 years ago by tom@…

We really don't need hundreds of examples - we understand the problem perfectly well, we just don't have a good way to fix it at the moment.

comment:6 Changed 10 years ago by steve8@…

The original problem of stacking motorway bridges over themselves up to layer 5 should now be resolved. Other cases are much more difficult. I will look at working round them when I get a chance.

comment:7 Changed 9 years ago by Ldp

  • Resolution set to fixed
  • Status changed from new to closed

Closing this one, as the case described here was fixed.

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