How to find vector tile URLs from GeoServer

Question

I have spent a lot of time trying to figure out the correct WMTS call to make to my GeoServer to get vector tiles (from my Leaflet web app), which I eventually found from the GetCapabilities: http://localhost:8000/geoserver/gwc/service/wmts?REQUEST=getcapabilities, where I was able to Ctrl+F to find ".pbf" which led me to this line:

<ResourceURL format="application/json" resourceType="TileJSON" template="localhost:8000/geoserver/gwc/service/wmts/rest/city:roads/{style}/tilejson/pbf?format=application/json"/>

Following the "template" value given here, it gave me 2 new URLs: http://localhost:8000/geoserver/gwc/service/wmts/rest/city:roads/{style}/EPSG:4326/EPSG:4326:{z}/{y}/{x}?format=application/vnd.mapbox-vector-tile, while the other URL just had EPSG:900913 instead of 4326.

My process was similar for the TMS server to find something with the format, but then I saw that the additional /{z}/{x}/{-y}.pbf values needed to be added from this post online:

http://localhost:8000/geoserver/gwc/service/tms/1.0.0/city:roads@EPSG:900913@pbf/{z}/{x}/{-y}.pbf

How are you properly supposed to find the URLs to WMTS and TMS services usually? I feel like I just stumbled upon this. New to this area.

Answer 1

For any OGC service you are correct to look in the getCapabilites response, it probably also helps to read the standards if you need to know more. A well designed client however should "know" all this and work it out for you.

Answer 2

From https://docs.mapbox.com/ios/maps/api/6.4.1/tile-url-templates.html :

{x} The index of the tile along the map’s x axis according to Spherical Mercator projection. If the value is 0, the tile’s left edge corresponds to the 180th meridian west. If the value is 2z−1, the tile’s right edge corresponds to the 180th meridian east.

{y} The index of the tile along the map’s y axis according to Spherical Mercator projection. If the value is 0, the tile’s tile edge corresponds to arctan(sinh(π)), or approximately 85.0511 degrees north. If the value is 2z−1, the tile’s bottom edge corresponds to −arctan(sinh(π)), or approximately 85.0511 degrees south. The y axis is inverted if the options parameter contains MGLTileSourceOptionTileCoordinateSystem with a value of MGLTileCoordinateSystemTMS.

So if you have langitude and longitude you can calculate x and y as follows (python):

x = int((lon + 180) / 360 * (2 ** z))
y = int((1 - (math.log(math.tan(math.radians(lan)) + 1 / math.cos(math.radians(lan)))) / math.pi) / 2 * (2 ** z))

while z is you zoom level