Maximum MBTiles size

[Thomas-Lerman]

Is there a maximum file size for using an MBTiles in 32-bit within an OLD osgEarth? I have a nearly 70 GB file that does not seem to load. I was able to load it with QGIS & others, gdalinfo seems to get an error, MbTilesViewer seems to lock up. Ideas?
P.S. Found we are getting the error, "No plugin found to load format "pbf"". This may tell me the problem as, I believe it is a vector tile layer instead of a raster layer. Is this supported in osgEarth? If not, is there a way to programmatically detect the error?

On the old osgEarth, I found I can change:
_rw = osgDB::Registry::instance()->getReaderWriterForExtension( _tileFormat );
to something like:

        _rw = osgDB::Registry::instance()->getReaderWriterForExtension( _tileFormat );                
        if (!_rw)
        {
            return (Status::Error("Unable to get reader writer"));
        }

[gwaldron]

Thomas,
70GB should not be a problem.
What you have is a Mapbox Vector Tiles (MVT) file, which is tiled vector data inside a sqlite database. Each tile is encoded as a PBF file (Google Protocol Buffers). How are you attempting to load it?

[Thomas-Lerman]

It looks like my original posting had a typographical error, plus I probably edited it after you got notification and fixed it. I meant 32-bit in an old osgEarth which crashes. In 64-bit (new osgEarth), it does not crash, but does not display the vector tiles.

Currently, we are setting it up (both old & new osgEarth) through osgEarth::Drivers::MBTilesOptions which the ImageLayer gets added to the osgEarth::Map. This works for raster tiles. Does osgEarth allow displaying the MVT (Gemini seems to indicate no)? Either way, any way to detect the MVT or error?

[gwaldron]

The osgEarth MBTiles layer type is for imagery and elevation only.

To access MVT stored in an mbtiles file, you can use the MVTFeatureSource. You can then pair this with a TiledFeatureModelLayer to render the contents in the styles of your choice.

auto features = new MVTFeatureSource();
features->setURI("data.mbtiles");
auto status = features->open();
...

Checking the return value of open() will let you know if it succeeded. You can also always just call layer->getStatus() for the same information.

There's no example earth file for MVTFeatures, but the osm.earth does a similar thing with a remote PBF dataset; so you can look at that for guidance.

Sorry, I don't know the answer to your 32-bit question.
But MBTiles stores its data in a single file, so the limitation would probably be filesystem dependent.

[Thomas-Lerman]

Thank you so much!!!

[Thomas-Lerman]

This all worked well. We found we could check open().isOk() from MBTilesImageLayer or MVTFeatureSource and fail to the opposite. It did not seem one direction was more efficient than the other, but would probably see more raster than vector. On all the MVT data we tried, we did notice it being a bit laggy at certain zoom levels, probably drawing way too much. Have you seen the same thing? Is there a default style that most use?

[gwaldron]

Not really.
If you are rasterizing it an image layer though, the performance should be the same for every tile.