h3 VS maplibre-gl-js

It looks like the base Kontur dataset uses H3 resolution 8, and there’s a lookup table here. “400m” seems to refer to the edge length (which averages to 461m).

I can speak to quadtrees, but the primary reason for using this is that you need a geographic "dictionary" (not using the word map to avoid confusion with charts), and you're perhaps already using the H3 hexagonal grid system.

HexSet: is a way of storing a set of H3 cells in a tree, and doing fast (2-20 ns on my 2013 trashcan Mac Pro) membership tests. You must first convert the input data (e.g. GeoJSoN polygon) into H3 cells.

> What an amazing tool that can completely change function names when it converts from C to Go.

How can one read the code of the benchmark, then switch into virulent sarcasm mode without trying to understand the code? And seeing "+1" comments without any effort to understand is also disheartening.

The blog post had a link about the Go helper functions the author used. It lands on https://github.com/akhenakh/goh3/blob/main/h3.go This shows that the `FromGeo()` function used by the Go benchmark is a helper that calls transpiled functions. The benchmark code itself was of course not transpiled, so the sarcasm was unneeded and wrong.

If anyone wants to dig in deeper, the C function `latLngToCell()` calls 2 functions, see https://github.com/uber/h3/blob/master/src/h3lib/lib/h3Index...

Uber just released their library to perform geospatial indexing - https://h3geo.org/. This might be an useful building block for you.

(.shp .gpkg ...) | ogr2ogr -> .geojson | tippecanoe -> .pmtiles

for OpenStreetMap data there's planetiler[4], and and openmaptiles[5] styles that work with Maplibre

with those combinations you've got a great start to something you can host for pennies on AWS S3+CloudFront or Cloudflare R2, with an open source data pipeline

[1] https://maplibre.org/

MapLibre GL JS v3.3.1

Does anyone else have a solution for the satellite layer? I was using MapLibre [0] then needed direct-on-the-ground images which made me convert to Google Maps.

[0] https://maplibre.org/

When using the Amazon Location Service, I recommend MapLibre GL JS, which I introduced in my previous article, "Amazon Location Service and AWS Amplify to Use Various Map Library," but you can also use any map library you like, including iTowns this time. I hope you will choose the map library of your choice, including iTowns!

Your browser has a very powerful image decoder built into it, offloading the PNG decoding into Javascript is very resource hungry.

Using maplibre (or any map viewer) you can load blobs of image data out of a tiff and use `Image` or `Canvas` to render the data onto a map.

Its even easier if the tiffs are already Cloud optimized as they perfectly align to a 1-to-1 map tile and they don't need to be rescaled, you can then just render the images onto the map. eg here is a viewer that loads webps out of a 15GB tiff and uses Canvas to render them onto a map [1]

Unless you are trying to layer all your maps together, you also could stop reprojecting them into webmercator, or if your goal is to layer them, then storing them in webmercator would save a ton of user's compute time.

There are a bunch of us that talk web maping and imagery in the #maplibre and #imagery slack channels in OSMUS's slack [2]

[1] https://blayne.chard.com/cogeotiff-web/index.html?view=cog&i...

[2] https://github.com/maplibre/maplibre-gl-js#getting-involved

The map is rendered by https://maplibre.org/, you can see how it is used here https://github.com/anvaka/map-of-github

Kudos to https://maplibre.org/ - amazing library