Opened 10 years ago

Closed 7 years ago

#2234 closed defect (invalid)

Purple overlay in some places at zoom 17

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


Mapnik at zoom level 17 looks like purple color is over the map.

Zoom 16: lat=54.97746,lon=82.89614
No image "zoom16.png" attached to Ticket #2234 Zoom 17: lat=54.97684,lon=82.8962

Whole my city looks like this at zoom 17.

I moved around the map and have found borders of the color fill. Links to it's corners:

lat=62.12446,lon=89.36298 - intersection
lat=62.33939,lon=89.49488 - intersection

In JOSM i created nodes at these coordinates and got this: Three rectangles, one large and two small.

What is it? I want it to disappear.

Attachments (2)

zoom16.2.png (56.8 KB) - added by yohanson 10 years ago.
zoom17.png (44.3 KB) - added by yohanson 10 years ago.

Download all attachments as: .zip

Change History (11)

Changed 10 years ago by yohanson

Attachment: zoom16.2.png added

Changed 10 years ago by yohanson

Attachment: zoom17.png added

comment:1 Changed 10 years ago by yohanson

Sorry for the ugly ticket, did not find how to modify it.

comment:2 Changed 10 years ago by Ldp

I've seen this issue before. Have you already submitted a ticket a while ago?

comment:3 Changed 10 years ago by yohanson

No, this is my first ticket. But I did create a forum topic, where no one answered:

comment:4 Changed 10 years ago by Ldp

I think I must have seen it on the forum, then. I didn't know then, and still don't know at the moment, what causes it.

comment:5 Changed 10 years ago by yohanson

It started to disappear! :)

comment:6 Changed 10 years ago by Ldp

We've switched over to the new tile server, yevaud, which is batch rerendering many old tiles.

Let's hope it doesn't return.

comment:7 Changed 10 years ago by Ldp

Resolution: fixed
Status: newclosed

I had a few tiles that were still purple rerendered, and that cleared it up for those. Still don't know what caused it.

comment:8 Changed 10 years ago by jburgess777@…

Resolution: fixed
Status: closedreopened

I am afraid this does still occur, e.g

I dug through the postgis queries for rendering that tile and it seems that the admin layer is the one which renders the bad data. There are two objects which both seem to cause an issue: way 28188776 & relation 60189.

Both of these two objects cover a very large geographic area. There was a crash once before in Mapnik when trying to render such large objects at a very small scale. The problem occurred when the scaled co-ordinates of the feature became so large that the pixel dimensions relative to the tile exceed 4 billion and overflowed the 32 bit arithmetic. See for details. I suspect we are seeing a similar overflow here.

comment:9 Changed 7 years ago by Ldp

Resolution: invalid
Status: reopenedclosed

Hopefully fixed in mapnik2, which is what we currently use.

Reopen if this still occurs somewhere.

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