Building a map with Mapzen terrain tiles
You can use Mapzen’s terrain tiles with a variety of browser-based rendering software packages. Following the syntax of the library you are using, you need to specify the URL to the Mapzen terrain tile service, the layers that you want to draw on the map, and styling information about how to draw the features.
Tangram is a WebGL browser based mapping engine and supports native iOS and Android rendering with OpenGL in 2D and 3D from vector and raster tiles.
The collect.py script in the examples downloads and collects GeoTIFF tiles within a bounding box and map zoom into a local directory and optionally merges them into one big file.
Download tiles into a named local directory:
python collect.py --bounds 37.8434 -122.3193 37.7517 -122.0927 --zoom 12 --mapzen_api_key mapzen-XXXXXXX directory/path/
When GDAL is installed, the collect script can optionally merge downloaded tiles into one large mosaic.
To trigger this behavior specify an output filename ending in
.geotiff and gdal_merge.py will be called to merge all downloaded tiles into a single image (and removes the intermediate files):
python collect.py --bounds 37.8434 -122.3193 37.7517 -122.0927 --zoom 12 --mapzen_api_key mapzen-XXXXXXX directory/path/merged_filename.tif
GDAL includes additional analytics, hill shading, and contouring algorithms. For instance, you could run gdaldem hillshade on the merged file to generate a basic hillshade. Mapbox has a great tutorial with full set of options.
Visualize the merged GeoTIFF image (see examples above) and perform analysis functions including generating contour lines and hillshades in QGIS, the free and open source GIS app.