MBTILES with missing tiles

adrian.huber's Avatar


02 Nov, 2019 07:27 PM

Hello Matt;
I have been creating MBTILES for offline use. I use shapefiles that I have obtained from our government agency, which I then convert into mbtiles via tilemill. For example, roads. What i am noticing is that if I use these MBTILES in sartopo, it appears that sartopo displays areas that have no roads with the 'square' that implies that there is no tile data. Basically, if I use the roads overlay on another map, wherever there is no roads, I think that those tiles are by design missing.
What should I do, is this a tilemill issue where I need to somewhere specify that it should generate blank tiles in areas where there is no data, or can i have SARTopo ignore missing tiles? I hope the screenshot makes more sense.

  1. 1 Posted by adrian.huber on 02 Nov, 2019 11:43 PM

    adrian.huber's Avatar

    Odd, I thought I had attached the screenshot. Here it is.

  2. Support Staff 2 Posted by Ben Lantow on 03 Nov, 2019 01:12 AM

    Ben Lantow's Avatar

    Hi Adrian,
    I see what the issue is. I'll pass this to Matt, if it's a quick and easy fix we will try to get it ASAP.

    Just out of curiosity what custom layers are you finding yourself generating frequently?


  3. 3 Posted by adrian.huber on 03 Nov, 2019 07:13 AM

    adrian.huber's Avatar

    This is the first time actually doing this. The layers that I am generating from shapefiles are:
    Streams Rivers and Lakes
    Contour lines
    Roads, logging roads, and trails
    This is all that I am starting with. I will be adding more as I get more information.
    -Adrian Huber

  4. Support Staff 4 Posted by matt on 04 Nov, 2019 03:40 AM

    matt's Avatar

    I think the issue is definitely that the tiles are missing. The square you're seeing is an artifact of the mapping library we're using, but the system as a whole isn't well set up to handle what you're describing (MBTiles files with partial coverage instead of full coverage within the bounding box).

    I'm not sure what the answer is, as I haven't used TileMill to produce MBTiles files in a while. Due to the way the files are compressed, filling in the gaps with transparent tiles shouldn't take up much space. Take a look in TileMill's settings and see if you can find a way to address this; if not I can probably get you a Python script to help fill in the missing tiles.

  5. 5 Posted by adrian.huber on 04 Nov, 2019 03:46 AM

    adrian.huber's Avatar

    This is a reasonable answer. I then just need to figure out what keywords to search for, to get the appropriate answer for TileMill. Any hints you have please share and I'll happily update this thread with my solution. So far I am able to rasterize MBTILES in under a few hours so doing some trial and error is affordable.
    Thanks Matt;

  6. Ben Lantow closed this discussion on 05 Nov, 2019 12:37 AM.

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