skipped zooms?

[incanus]

What's the use case for something like this, where zoom levels are skipped?

zooms: [0, 2, 3, 4, 5, 6, 7, 8, 10, 12, 13, 14],

https://github.com/mapbox/llmr/blob/7b561b52d0a958143672b0cc717c5d17feeb71d3/debug/site.js#L16

This comes into play over in llmr-native data source instantiation, i.e. why not just provide min and max zooms instead of this range?

[mourner]

@incanus as far as I understand, this is due to the vector tiles currently not being optimized for each zoom very well — e.g. we can have the same data with the same simplification on different zoom levels. See also #48 (comment) and https://github.com/mapbox/mapbox-streets/issues/740

I suppose it may go away once the VT source is good across the whole zoom range. cc @rclark @ajashton

[kkaefer]

This would also allow us to only load every other zoom level to reduce data transfer. However, it's probably better to include as few data in a tile as possible to get smaller tile sizes, and just load tiles on every zoom level. native currently doesn't have this option.

[ajashton]

Ya we are working on being more aggressive about simplification per zoom level, but there are already lots of data differences between every zoom level of the vector tiles. For example, we select only water bodies and landuse areas that meet certain size thresholds for the given scale (example query). We also bring in labels gradually over different zoom levels.

With vector terrain the differences affect the design more obviously - eg the hillshades were generated with specific generalization & exaggeration settings for each zoom level, so I wouldn't want to skip any.

If low-zoom OSM landcover polygons are a problem we could perhaps drop them and encourage use of our new landcover layer instead which is heavily merged & simplified.

[mourner]

Can be closed, right? BTW, I made this a bit easier in #369 — now if you don't specify zooms explicitly, you can just specify maxZoom (and minZoom, 0 by default) and it will use all zooms in between. Additionally, you can specify skipZooms — an array of zooms to be skipped.

[incanus]

Yes, thanks for the clarifications. Tracking this in a parity ticket on native, too.