overzoom when using mbtiles files?

[danbjoseph]

is it possible to add overzoom when using an mbtiles file as a basemap?

reason: for offline surveys when low bandwith makes it hard to download large files. we generated remotely an mbtiles file and need to get it to the field. for one of our AOIs the z20 mbtiles is 217mb and the z18 file is 60mb. at z18 it is difficult to select individual buildings.

[felixholl]

that would be a very useful feature for our intended use case in malaria surveillance too.

[hallahan]

The Mapbox Android SDK doesn't do this, but you can trick it. Open up your MBTiles db in sqlite and change the maxzoom property in the metadata table.

My SQLite app of choice is SQLite Studio.

I can look into finding a better solution...

[danbjoseph]

interesting workaround. in the little bit i played around, it doesn't seem to like panning when overzoomed. when panned around at overzoom the basemap would drop out and then you had to zoom out to a level at which tiles exist and then zoom back in.

[danbjoseph]

on a side note (but still concerning file size) is there a way to generate an mbtiles file for an irregular polygon (or multipolygon) area. not just a max-min/lat-lng bounding box. for instance if you were surveying a couple of small villages and wanted one base map file and knew you didn't need all the area in between.

[hallahan]

Not that I know of. You could try using some SQL and remove what you want yourself...

[dalekunce]

The overzoom option would be cool, and save a ton of space.

[hallahan]

Should we defer to new map renderer? This would require enhancing the depracated lib? Close?

[dalekunce]

Let's leave this open until its verified that the new renderer will work as we need it to.

[dalekunce]

switch to new renderer should solve this.

[hallahan]

Not possible with legacy mapping library. GL libs do this.