Generating vector tiles

Cache generation

A tile cache can be generated with the t_rex generate command:

USAGE:
    t_rex generate [OPTIONS] --config <FILE>

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information

OPTIONS:
    -c, --config <FILE>                             Load from custom config file
        --extent <minx,miny,maxx,maxy>              Extent of tiles
        --loglevel <error|warn|info|debug|trace>    Log level (Default: info)
        --maxzoom <LEVEL>                           Maximum zoom level
        --minzoom <LEVEL>                           Minimum zoom level
        --nodeno <NUM>                              Number of this nodes (0 <= n < nodes)
        --nodes <NUM>                               Number of generator nodes
        --overwrite <false|true>                    Overwrite previously cached tiles
        --progress <true|false>                     Show progress bar
        --tileset <NAME>                            Tileset name

Usage

Generate tiles for cache:

t_rex generate --config config.toml

MBTiles creation

To create MBTiles files with vector tiles from a local cache you can use MBUtil.

Example:

mb-util --image_format=pbf /tmp/mvtcache/streets streets.mbtiles

Drilldown

For analyzing and testing tileset configurations, a drilldown command collects statistics at given coordinates.

The statistics are printed to standard output and formatted as CSV.

USAGE:
    t_rex drilldown [OPTIONS] --config <FILE>

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information

OPTIONS:
    -c, --config <FILE>                             Load from custom config file
        --loglevel <error|warn|info|debug|trace>    Log level (Default: info)
        --maxzoom <LEVEL>                           Maximum zoom level
        --minzoom <LEVEL>                           Minimum zoom level
        --points <x1,y1,x2,y2,..>                   Drilldown points
        --progress <true|false>                     Show progress bar
        --tileset <NAME>                            Tileset name

Example:

t_rex drilldown --config mvtbench.toml --points 8.528674,47.370217,9.437237,47.050807 >stats.csv

Columns:

• count: Number of measurements
• min: Minimal measured value
• max: Maximal measured value
• mean: Mean value of measurements
• stddev: Standard deviation of measurements
• key0: metric name
• key1: tileset
• key2: layer
• key3: zoom

Measurements:

• tile_ms: Tile creation time in milliseconds
• feature_count: Number of features in tile
• tile_bytes: Size of tile in bytes (uncompressed)