I’m trying to add country borders to our app which is using Google Photorealistic 3D Tiles.
From my research, it seems that the best way would be to use a vector format for that, but it seems that’s not available for Cesium Unity yet.
I assume my next best option is as described here:
After a long journey (pretty much all map related stuff is new to me) I managed to find a way to get country borders as a GeoJSON, EWKT, EWKB or OSM-Poly file via https://osm-boundaries.com. So I select my country, output it as GeoJSON, open that in QGIS and export a PNG file (because I need transparency) and a PGW world file.
I then upload those to Cesium ION:
Unfortunately I get the following error:
Now, like I mentioned, I’m new to all of this. I assume “spatial reference system” refers to the “Target CRS” I can set in QGIS Georeferencer?
But where does Cesium ION expect to find this information? The DE2.pgw world file only contains these 6 lines, which seems expected according to Wikipedia:
So, that’s where I’m stuck now. If I export it to (Geo?)TIFF it works, but I need transparency, and the TIFF file is unnecessarily large anyway, and I’m stuck with low upload speeds. But he PNG/PGW file combination doesn’t seem enough. I didn’t find a way to additionally export the Target CRS information, and since I don’t know how Cesium ION expects it in the first place, I can’t construct a file manually either.
Apart from that: Does this seem like the best way to add country borders in Cesium Unity? Is there any better or easier way? Is there a better way to tackle any parts of this process? I discovered all tools and information used for this over the last hours (well, apart from Unity and Cesium ) so I have no idea if I’m doing things right and I’m thankful for any information!