The basemap in a Panorama application is actually made up of two (at least) tile layers.
The bottom tile layer is generated dynamically from CartoDB. On top of this layer there is one or more semi-transparent tile layers which are not loaded from CartoDB. For the American Panorama atlases, we use this overlay layer to load a hillshade to show terrain. However, you could load any external tile layers you wish.
Currently sourced from Stamen's OpenTerrain project. XYZ url template for this layer is definied in tileLayers.json. You could use any external tile layer here, but keep in mind that it would obscure any CartoDB tile layers below. Note that the "layers" is an array, so you can also define more than one tile layer here, assuming all but one of them are semi-transparent.
Example of tileLayers.json:
{
"layers": [
{
"url": "http://sm.mapstack.stamen.com/openterrain_2163/{z}/{x}/{y}.png"
}
]
}
The cartodb folder contains multiple files which the build process uses to generate a basemaps.json file (not included in the repository) which is a MapConfig file is sent to the CartoDB Maps API to generate an "anonymous map" tile layer.
You need to modify at least three files: basemaps.yml, config.json, and layers.yml, plus however many style files you need for your layers, which are placed in styles/*.mss.
The basemaps.yml file defines which layers you want to include in the resulting tile layer, and which order they should appear.
The layers.yml file defines the CartoDB SQL for each of the layers in basemaps.yml.
The config.json file specifies your CartoDB userID, and an optional apiKey if you are using private tables.
For each layer defined in layers.yml, you need to have a .mss file in the styles/ folder that has the exact same name as the layer.
- What else to do in the .yml files
- How to debug with Tessera
- How to develop using CartoDB Editor
- How to organize your CartoDB tables, reproject them, and make them public