4 ms·
Aren't those vector tiles a little heavy, since they're likely json? Of course I can guess a lot of data can be removed and simplified, but still, PNG seem lig
by jokoon 6y ago
Aren't those vector tiles a little heavy, since they're likely json?
Of course I can guess a lot of data can be removed and simplified, but still, PNG seem lighter...
- durkie 6y agoIt depends on the application, but I don't think they're necessarily larger in size. I believe the format is quite compressed (Mapbox Vector Tile/MVT, which I believe is a variant of protocol buffers). Many vector tile encoders have wide flexibility in geometry simplification/removal depending on zoom layer and this helps big time with tile size. I find them to be quite nice in lower bandwidth situations because you can overzoom them and still have them look good: if you zoom in and the tiles for the next zoom level haven't loaded, the vector geometry is still able to look decent, rather than pixellated like a raster tile.
- jokoon 6y agoCompressed? Are you saying decompression is done with JS?
- nbadg 6y agoYou're mixing up the formats slightly: MVT is sqlite with a particular schema; OSM raw data is PBF with a particular schema.
- durkie 6y agoIsn't mbtiles sqlite?
- nbadg 6y agoIt might be that pbfs are stored inside sqlite? The whole thing is really incredibly confusing to be honest. What I can tell you is that my vector slippymap XHR is requesting .pbf files, so that would definitely imply protobuffers as the wire format. Ultimately that's using t-rex and mapbox-gl.js, so... not sure if there's something intermediate. But the mapbox docs say sqlite? I'm just very confused now.
- maxerickson 6y agohttps://docs.mapbox.com/vector-tiles/specification/ https://docs.mapbox.com/vector-tiles/specification/
- nbadg 6y agoYep, versus https://docs.mapbox.com/help/glossary/mbtiles/ https://docs.mapbox.com/help/glossary/mbtiles/ -- I had them backwards. My confusion might have been because of the name similarities (mbtiles vs mvt), which took me 3 tries to even just type correctly.
- nbadg 6y agoI believe, but haven't bothered to profile, that they're lighter. You can also pre-"render" the vector tiles and store them in eg S3. All styling is done in-browser, which means you can do neat things like swap out the styles client-side for dark mode without needing to reload map tiles. The primary standard for vector tiles is Mapbox Vector Tiles (it's an open standard), which is really just a sqlite database following a particular schema. My own personal experience developing against both png and vector tiles over the past few months is that vector tiles are better in just about every way for the kinds of things you use maps for in apps. I expect that some dataviz applications, though, would be better served by raster tiles, since you'd end up generating a raster overlay anyways.