Opened 11 years ago

Closed 6 years ago

#1706 closed defect (invalid)

Broken casing at intersection of two ways on different layers

Reported by: jesusfreak Owned by: mapnik-team@…
Priority: major Milestone:
Component: mapnik Version:
Keywords: Cc:

Description

Have a look at http://www.openstreetmap.org/?lat=51.049788&lon=13.738007&zoom=18&layers=B000FTF The vertical lanes are in the underground garage on layer -1, the horizontal road "Wilsdruffer Straße" is on layer 0. The casing of the Wilsdruffer Straße should be closed, which is not the case at the moment.

Change History (6)

comment:1 Changed 11 years ago by steve8@…

Unfortunately, mapnik can't recognise (and thus filter for) layer numbers implicitly. It might be considered tagging for rendering, but if these ways are in a carpark building then then could be tagged as tunnel=yes, and render would place them under the roads, and not cut into the casings. Argument for that - they are not visible from above, as inside the building. On the other hand if they are not underground (or inside a building) then perhaps the tertiary road should be tagged as a bridge, if it goes over these service=parking_aisles, which are thus at ground level. You tell me...

comment:2 Changed 11 years ago by JasonWoof

This is a problem even without layers.

If two ways cross, but do not share a node, then this indicates that they do not touch in reality, and the renerer should draw the casings of one over the other. Unfortunately without layer information the renderer can't know which to draw on top, but it must pick one. It should not (as it seems to now) draw an intersection.

comment:3 Changed 11 years ago by Vid the Kid

comment to Jason Woof: I don't think that's right. Mapnik doesn't draw the casings specifically; instead it draws a thinner line over a slightly thicker line. When two roads cross, the order in which these lines are drawn depends on whether it looks like one is going over the other, or a level intersection. The layer tag (if present) is supposed to determine that order.

comment to anyone: The problem seems to be that Mapnik doesn't pay attention to the layer tag at all except for bridges and tunnels, and even then not thoroughly. It seems that bridges of different highway type don't appear to intersect on the same level, even with the same layer value. More recently, it seems that (at least for some highway types - there are tickets for that) bridges of the same highway type appear to intersect on the same level, even if they're given different layer values.

comment:4 Changed 11 years ago by steve8@…

Owner: changed from steve8@… to mapnik-team@…

comment:5 Changed 6 years ago by math1985

The layer key should not be used without the tunnel or bridge key. In the concrete example given, the tunnel tag has been added. Therefore, I close this issue now.

comment:6 Changed 6 years ago by math1985

Resolution: invalid
Status: newclosed
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