scene.yaml

camera:
    type: perspective
    focal_length: [[16, 2], [20, 6]] # pairs of [zoom, focal len]
    vanishing_point: [-250, -250] # relative to center of screen, in pixels

lights:
    light1:
        type: directional
        direction: [.3, 1, -.5]
        diffuse: 1
        ambient: 0.5

sources:
    nextzen:
        type: MVT
        url: https://tile.nextzen.org/tilezen/vector/v1/512/all/{z}/{x}/{y}.mvt
        url_params:
            api_key: d161Q8KATMOhSOcVGNyQ8g
        tile_size: 512
        max_zoom: 16

layers:
    earth:
        data: { source: nextzen, layer: earth }
        draw:
            polygons:
                order: function() { return feature.sort_rank; }
                color: [0.175, 0.175, 0.175]

    landuse:
        data: { source: nextzen, layer: landuse }
        draw:
            polygons:
                order: function() { return feature.sort_rank; }
                color: [0.5, 0.875, 0.5]

    water:
        data: { source: nextzen, layer: water }
        draw:
            polygons:
                order: function() { return feature.sort_rank; }
                color: [0.5, 0.5, 0.875]
        outline:
            # only show outlines at z14 or higher
            filter: function () { return (feature.kind != 'ocean' && feature.kind != 'riverbank') && $zoom >= 14; }
            draw:
                lines:
                    order: function() { return feature.sort_rank; }
                    color: [0.6, 0.6, 0.975]
                    width: function() {return (2.5 * Math.log($zoom));}

    roads:
        data: { source: nextzen, layer: roads }
        filter:
            - is_tunnel: no
            - not: { kind: [ferry] }
        draw:
            lines:
                order: function() { return feature.sort_rank; }
                color: [0.8, .8, .8]
                width: 8
        highway:
            filter: { kind: highway }
            draw:
                lines:
                    width: 10
                    outline:
                        color: [0.2, 0.2, 0.2]
                        width: 3
        major_road:
            filter: { kind: major_road }
            draw:
                lines:
                    width: 8
                    outline:
                        width: 1
        minor_road:
            filter: { kind: minor_road }
            draw:
                lines:
                    width: 5
                    outline:
                        width: 1
        path:
            filter: { kind: path }
            draw:
                lines:
                    width: 6
                    outline:
                        width: 1
        rail:
            filter: { kind: rail }

    buildings:
        data: { source: nextzen, layer: buildings }
        draw:
            polygons:
                # make sure buildings are on top of all the separated road layers
                order: function() { return feature.sort_rank || 1000; }
                color: [.5, .5, .5]
                # at z15, only extrude buildings at least 20 m tall; at z16 and higher, extrude everything
                extrude: function () { return (($zoom >= 15 && feature.height > 20) || $zoom >= 16) }