Skip to content
This repository has been archived by the owner on Jul 24, 2021. It is now read-only.

Purple overlay in some places at zoom 17 #2234

Closed
openstreetmap-trac opened this issue Jul 23, 2021 · 9 comments
Closed

Purple overlay in some places at zoom 17 #2234

openstreetmap-trac opened this issue Jul 23, 2021 · 9 comments

Comments

@openstreetmap-trac
Copy link

Reporter: yohanson
[Submitted to the original trac issue database at 7.01am, Friday, 28th August 2009]

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

Zoom 16: [http://www.openstreetmap.org/?lat=54.97746&lon=82.89614&zoom=16&layers=B000FTF lat=54.97746,lon=82.89614] [[BR]]
[[Image(zoom16.png)]]
Zoom 17: [http://www.openstreetmap.org/?lat=54.97684&lon=82.8962&zoom=17&layers=B000FTF lat=54.97684,lon=82.8962] [[BR]]
[[Image(zoom17.png)]]

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:

[http://www.openstreetmap.org/?lat=62.12446&lon=89.36298&zoom=17&layers=B000FTF lat=62.12446,lon=89.36298] - intersection [[BR]]
[http://www.openstreetmap.org/?lat=62.33939&lon=89.49488&zoom=17&layers=B000FTF lat=62.33939,lon=89.49488] - intersection [[BR]]
[http://www.openstreetmap.org/?lat=54.41899&lon=89.36284&zoom=17&layers=B000FTF lat=54.41899,lon=89.36284] [[BR]]
[http://www.openstreetmap.org/?lat=62.33935&lon=89.36313&zoom=17&layers=B000FTF lat=62.33935,lon=89.36313] [[BR]]
[http://www.openstreetmap.org/?lat=62.55298&lon=89.86818&zoom=17&layers=B000FTF lat=62.55298,lon=89.86818] [[BR]]
[http://www.openstreetmap.org/?lat=62.12428&lon=78.20105&zoom=17&layers=B000FTF lat=62.12428,lon=78.20105] [[BR]]
[http://www.openstreetmap.org/?lat=62.12455&lon=89.49456&zoom=17&layers=B000FTF lat=62.12455,lon=89.49456] [[BR]]
[http://www.openstreetmap.org/?lat=62.33954&lon=89.8682&zoom=17&layers=B000FTF lat=62.33954,lon=89.8682] [[BR]]
[http://www.openstreetmap.org/?lat=62.553&lon=89.4949&zoom=17&layers=B000FTF lat=62.553,lon=89.4949] [[BR]]
[http://www.openstreetmap.org/?lat=54.419&lon=78.201&zoom=17&layers=B000FTF lat=54.419,lon=78.201] [[BR]]

In JOSM i created nodes at these coordinates and got this:
[[Image(http://id.piccy.info.nyud.net/i4/d2/16/a05b2b1ba5e659506a14787349d5.png, 120px)]]
Three rectangles, one large and two small.

What is it? I want it to disappear.

@openstreetmap-trac
Copy link
Author

Author: yohanson
[Added to the original trac issue at 9.01am, Friday, 28th August 2009]

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

@openstreetmap-trac
Copy link
Author

Author: Ldp
[Added to the original trac issue at 11.18am, Friday, 28th August 2009]

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

@openstreetmap-trac
Copy link
Author

Author: yohanson
[Added to the original trac issue at 11.26am, Friday, 28th August 2009]

No, this is my first ticket. But I did create a forum topic, where no one answered: http://forum.openstreetmap.org/viewtopic.php?id=4042

@openstreetmap-trac
Copy link
Author

Author: Ldp
[Added to the original trac issue at 10.05am, Monday, 31st August 2009]

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.

@openstreetmap-trac
Copy link
Author

Author: yohanson
[Added to the original trac issue at 11.18am, Wednesday, 9th September 2009]

It started to disappear! :)

@openstreetmap-trac
Copy link
Author

Author: Ldp
[Added to the original trac issue at 11.44am, Wednesday, 9th September 2009]

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

Let's hope it doesn't return.

@openstreetmap-trac
Copy link
Author

Author: Ldp
[Added to the original trac issue at 9.08pm, Friday, 18th September 2009]

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

@openstreetmap-trac
Copy link
Author

Author: jburgess777[at]googlemail.com
[Added to the original trac issue at 11.27pm, Monday, 5th October 2009]

I am afraid this does still occur, e.g http://b.tile.openstreetmap.org/17/98256/36295.png

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 http://trac.mapnik.org/ticket/253 for details. I suspect we are seeing a similar overflow here.

@openstreetmap-trac
Copy link
Author

Author: Ldp
[Added to the original trac issue at 10.05pm, Thursday, 8th March 2012]

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

Reopen if this still occurs somewhere.

Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.
Projects
None yet
Development

No branches or pull requests

1 participant