Could you point me in the right direction on how to create vector tiles from geojson or topojson?
mapnik-vector-tile seems to be the right library but I cannot find a good example.
There seems to be examples of geojson files (14_2620_6331-XXX) but how did the pbf files get created?
Thanks.
Pat.
The vector tile code has a repository with examples, including output in protobuf.
Related
I'm trying out Mapbox for the first time, and playing around with drawing some polygons in the dataset editor for export to a tileset. However, the polygons in the resulting tileset are not the same as what I create in the editor. The polygons are only very rough, simplified approximations of the originals.
In dataset editor:
In map layer as tileset export:
I understand that Mapbox does vector simplification at certain zoom levels, but these changes are not zoom-dependent. I zoom in all the way and the shapes are still like this.
Moreover, such extreme degredation of the geometries makes tilesets essentially useless for features that require any sort of accuracy, like property lot lines.
Am I missing something, or is this really the expected behavior? Is there really no way to get accurate geometries into a tileset?
UPDATE: It appears this is only happening with shapes I create by drawing in the Mapbox data editor. So far the geometries that I've uploaded as geojson files have gotten converted to tilesets accurately...
I suspect this is because the maxzoom is too low.
When you create a Mapbox Tileset, either by uploading GeoJSON directly as a new Tileset, or by exporting your your Dataset to a Tileset, Mapbox will try to guess an appropriate minzoom and maxzoom of the Tileset.
Sometimes the min/max zoom's used aren't suitable for the map you're trying to create. Since there is no way to specify a maxzoom in either of the two approaches the only alternative is to create your Tileset locally with https://github.com/mapbox/tippecanoe specifying an appropriate maxzoom for your data and then uploading the resulting .mbtiles as a Mapbox Tileset.
I'm trying to make my own renderer for Mapbox MVT vector tiles, but I have hit the obstacle and couldn't find the answer. My problem is that MVT tile downloaded form Mapbox server contains all roads, but only a few bulding numbers (should be much more for given area) and no land types (grean area on map) and buildings.
Anyone had same problem or know the answer?
link I use to download tile is:
https://api.mapbox.com/v4/mapbox.mapbox-terrain-v2,mapbox.mapbox-streets-v7/18/143415/87627.mvt?access_token={access_token}
Below raster tile for the same area:
The trick is in decoding MVT tiles (using mapbox-vector-tile-java), to parse it properly MvtReader.RING_CLASSIFIER_V1 needs to be used:
final JtsMvt result = MvtReader.loadMvt(f, new GeometryFactory(), new TagKeyValueMapConverter(), MvtReader.RING_CLASSIFIER_V1);
Resolved thanks to boldtrn commit on mapsforge/vtm
Mapbox provides a kindle of map tiles--mapbox.mapbox-terrain-v2 which is stored in pbf format and saved in mvt suffix. The height data is represented by contour (line).
I want to generate terrain with satellite texture and this height data in Unity3D. How could I convert this pbf data to a height map(a pixel for a height value)?
There is an example
https://api.mapbox.com/v4/mapbox.mapbox-terrain-v2/12/1171/1566.jpg?access_token=pk.eyJ1Ijoib2xlb3RpZ2VyIiwiYSI6ImZ2cllZQ3cifQ.2yDE9wUcfO_BLiinccfOKg
And the mvt file
https://api.mapbox.com/v4/mapbox.mapbox-terrain-v2/12/1171/1566.mvt?access_token=pk.eyJ1Ijoib2xlb3RpZ2VyIiwiYSI6ImZ2cllZQ3cifQ.2yDE9wUcfO_BLiinccfOKg
And the document of Mapbox:
https://www.mapbox.com/vector-tiles/mapbox-terrain/
https://www.mapbox.com/vector-tiles/specification/
MapBox have buid a Unity3d package: MapBox-Unity-SDK
SDK here : https://www.mapbox.com/unity/
Just click download.
This is an asset you can open in Unity directly.
Launch Unity3d, goto Menu>Assets>ImportPackage>CustomPackage
and select your downloaded file.
It will unpack some files and the folders, you will find into some exemples scene files to help you.
The current vector terrain layer isn't designed to be turned into a heightmap: we've processed terrain into elevation contours and lines, so turning those back into raw data would be difficult (much like doing the opposite: we do a lot of processing because it would also be difficult to transfer raw data and derive visual data).
A new and improved vector terrain model that supports your usecase is on the way, but we've also introduced RGB terrain, which was actually designed specifically to address cases like Unity - decoding the RGB-encoded elevation tiles tends to be much simpler in software.
My map's source file is GeoJSON, but it is very large and very slow. Is there a way to convert this to vector tiles on the fly using MapBox GL JS? (Load the GeoJSON, pre-process the file into vector tiles, and show use the vector tiles as the base map.) It seems that vector tiles are much faster.
I've tried all the GeoJSON-VT tutorials and examples that I could, like the one on MapBox's site, but it just says that GeoJSON-VT works under the hood, so it isn't much help. The others mostly apply to Leaflet, not MapBox GL JS.
Meanwhile, every example I find that uses a large dataset always does so via vector tiles:
map.addSource('x', {
"type": "vector",
"url": "url"
});
For reference, I am loading my file using this method:
map.addSource('x', {
type: 'geojson',
data: 'file.geojson'
});
In case your GeoJSON file is static, you could use mapbox/tippecanoe to convert the GeoJSON to an .mbtiles file. You could then either upload the file to Mapbox as a tileset (about tilesets) or you could serve your own vector tile source from a web server using the .mbtiles file (reference implementation).
If your GeoJSON file is more dynamic, things get a little bit more complicated. I have never used it, but Mapbox Dataset API might be a good solution for that.
To the best of my knowledge, Mapbox-GL-JS uses GeoJSON-VT to automatically convert client-side-loaded GeoJSON files into vector tiles within the browser - so it's already doing what you're asking for.
If this is still "slow", probably the problem is the actual loading and processing - so pre-generating and serving vector tiles is the right answer.
Learning Leaflet. Had success with point data. Now want to create polygons.
The process starts with an Access record with a Parcel Identification Number. Using ArcMap desktop, the records are joined to a parcel shape file for the county.
What the best approach to get to Leaflet polygons from here? Like with point data, do I need to add fields to contain the lat/lon data?
I don't need a lot of detail; just a pointer in the right direction. I don't mind doing homework.
My approach would be to convert the shapefile to geojson and then load the geojson into your Leaflet map.
I'm aware of some ArcGIS plugins to export geojson, but an alternative approach is to use the command line tool GDAL (ogr2ogr).
See the links on this answer for more details, but the command will end up being something like the following...
ogr2ogr -f GeoJSON -t_srs "EPSG:4326" [name][.geojson|.json] [name].shp
From there you can preview the results in geojson.io or github before creating your Leaflet map.