I made the switch from raster to Vector Tiles for my maps sometime last year and so far I've been really satisfied with my decision. I have been making tiles from zoom 1 to 21 and it's been a real struggle trying to tile large areas till zoom 21.

I realized that since vector tiles contain just the vector data they are essentially the same for higher zoom levels, just of a smaller extent, so I could skip making the tiles and simply reload the previous zoom level's tiles. I tested it out by limiting my max zoom to 17 and viewing the map at zoom 21 (zoom 17 tiles reloaded at zoom 21) and couldn't find a difference in the rendered map (the missing labels can be handled in my renderer).

This is the original zoom 21( with zoom 21 tiles): enter image description here

And this is the zoom 21 with zoom 17 tiles reloaded: enter image description here

Can I skip making tiles for zoom 18+ and use the zoom 17 tiles till zoom 21 without any problems?

I am using TileStache to make my vector tiles (for Pakistan only, not globally) and it stops simplifying geometries from zoom 16

  • Are you generating all of your vector tiles up-front? Can you generate them dynamically instead, i.e. only cut a vector tile when it is requested? Something like node-mapnik can be used for this. These can still be cached, but you won't need to create them all before you can start rendering them. Globally, zoom 19 has more than 270 billion tiles. – Richard Law Sep 9 '16 at 7:52
  • generating them dynamically significantly reduces the performance, I do try to generate as much of them up front as I can but I keep the option for generating them dynamically open. I cache the major cities (areas that get viewed often) upfront. – Hasan Mustafa Sep 9 '16 at 8:00
  • I am only working on Pakistan for now, not globally. – Hasan Mustafa Sep 9 '16 at 8:01

Upon further testing and research I have found out that I can over-zoom the zoom 17 tiles all the way up to zoom 21 without any problems. Since the VectorTiles contain only the underlying geometry, and I am not simplifying the geometry, I am essentially getting the same information in the tiles just for a smaller extent (when I get zoom 18 onwards tiles).

This is good explanation of overzooming.

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