Tiles from wrong zoomlevel on OpenStreetMap

[Jonas]

Hi Don

Thanks for your response. Somehow, your post has disappeared again from the site, maybe some issues with the redesign of your site.

I have sent a project that should make it possible for you to reproduce the issue. It includes a Visual Studio project and also a video wherein I reproduce the issue (21 seconds into the video). The shapefiles on the map are in different projection than the map, but I did not bother to convert projection so they are placed in a weird position, please ignore that.

I use MapSuite 9.0.0.175 (wpf desktop) dlls.

I found this other thread discussing the same issue:

Zooming and Tile from Wrong Zoom Level Shown

Hi,  I’ve been doing some work with the OpenStreetMap layer and have notice a little quirk when zooming in and out on the map (using version 8.0.0.46)  I’ve been using the mouse wheel to do the zoom (because it’s so convenient) but now and again I’ll see a tile on the map that doesn’t belong there. It’s the tile from another zoom level see it in the attached image.  I can make the happen fairly regularly and am using the following code to add the layer: Dim osm As New OpenStreetMapOve…

To address your three points again:

1: Continue use multiply tile mode is OK, but the single tile will render the map after get the whole image, if you found singletile looks slow, that means your machine view OSM maybe not fast enough.

We will use HybridTile for OpenStreetMap overlay. SingleTile locks the map and gives a bad user experience, even on my modern i7 workstation with 1 gigabit connection.

2: I guess why that happen because when you zoom in one or more tiles hadn’t got response from the server, so it can only keep original image. If that’s the reason, it related with the network speed, so I suggest to find the fastest server, which can reduce the issue. I think you can just use single url for test, then find which one looks faster.

If network speed causes the framework to cache tiles from the wrong zoomlevel, I think the issue is primarily in the framework, not in the network speed. We have customers all over the world, and we cannot expect them all to have top notch network speed. That said, it even fails in my office, and as mentioned I’m on a 1 gigabit connection with low ping.
I have tried to use the CustomServerUris - I found that I could try to connect to http://a.tile.openstreetmap.de/{0}/{1}/{2}.png instead of http://a.tile.openstreetmap.org/{0}/{1}/{2}.png, but all I got was the pink exception tiles. Do you have some kind of documentation for OpenStreetMapOverlay?

3: By default the cache for overlay should be closed, if you assign cache for it, the tile will be cached to local, please can add code to manage them follow the usage terms.

The OpenStreetMapOverlay has a tilecache by default in \AppData\Local\Temp\MapSuite\OpenStreetMapTmpTileCache.

Best regards
Jonas