tileGet should support downloading rendered tiles from openstreetmap

[RobertHilbrich]

In addition to MapQuest, ArcGIS and Google, we should try to support downloading of OSM tiles too.

[RobertHilbrich]

In principle, we would like to offer OpenStreetMap background tiles in SUMO. For this purpose, tileGet.py has been extended to be able to process OpenStreetMap tiles. Please see the tile usage policy in OpenStreetMap.

However, due to projection differences between the sumo network (often in UTM projection) and the tile images (in web mercator projection), the stitching of the background images is not really pretty - see below.

https://openstreetmap.org/copyright

We discussed multiple possible solutions.

1. Modifying tile images from OpenStreetMap to match UTM projection --> would distort those images including the fonts --> not pretty
2. Use vector tiles from somewhere and re-project those tiles to UTM --> take those tile from where?
3. Use another open data set for the background images, like https://data.nasa.gov/dataset/World-Map/7zbq-j77a --> does the background image for the tiles match the road network taken from OpenStreetMap
4. Re-project existing sumo networks from UTM to web mercator --> might be tricky as edges may get lost. This will however work with newly generated scenarios via the WebWizard, when you can create a "new" sumo network with the proper projection from the original OpenStreetMap data. (see also fix satelite background projection glitches #6539)
5. Provide a custom tile server serving tile images for OpenStreetMap data in UTM projection.

The best solution would probably be 5). We will check, if the German Aerospace Center might be able to provide such a service. Closing the issue for now.