Creates a random DEM (Digital Elevation Model) using trees of gaussian kernels (see Random DEM Generator for more details).

This script was developed with Python 2.7 and relies on numpy (1.13.1) and osgeo (1.10.1).

Just copy dem_generator.py to your computer and run the following command in a terminal: python dem_generator.py <parameters>

You can use python dem_generator.py -h to get a full list of possible parameters.

• Output DEM path (madatory). The DEM mus have a .tif extension.
• --height <value> DEM height in pixels (optional). Default value is 1000.
• --width <value> DEM width in pixels (optional). Default value is 1000.
• --verbose verbose mode (optional).

The generation of a DEM relies on multiple and somewhat advanced parameters. Preset parameters can be used with the --preset <mode> option in order to avoid manually tuning these parameters. The --preset option currently supports two modes: archipelago and mountainous_island. See examples below:

Example output of python dem_generator.py /path/to/dem.tif --width 1500 --preset archipelago

Example output of python dem_generator.py /path/to/dem.tif --width 1500 --preset mountainous_island

If you want to manually tune the DEM generation parameters, here is the list of editable options -- they are all optional:

• --waterratio <value> ratio of water (i.e. negative elevation) in the DEM. Range: 0-1. Default value is 0.5.
• --island island mode; this means the borders (1-px padding) of the DEM will always have a negative value. This option may result in a final water ratio higher than the --waterratio option. Default value is False.
• --scale <value> scale of main features (for example, islands size) relative to the whole DEM. Range: 1-100. Default value is 20.
• --detailslevel <value> level of features details. Range: ≥0. Default value is 3.
• --spread <value> features spread. Range: 1-6. Default value is 3.
• --roughness <value> features roughness (higher value means more "mountainous"). Range: 1-10. Default value is 5.
• --directionality <value> features directionality (higher value means more elongated features). Range: 1-10. Default value is 5.

Warning: when increased, the scale, detailslevel, spread and roughness options can dramtically increase the generation time.

Here a few examples of the role of some parameters on the result:

• scale:

--scale 10	--scale 15	--scale 20 (default)

• details level:

--detailslevel 1	--detailslevel 3 (default)	--detailslevel 5

• spread:

--spread 1	--spread 3 (default)	--spread 5

• roughness:

--roughness 1	--roughness 5 (default)	--roughness 8

• directionality:

--directionality 1	--directionality 5 (default)	--directionality 10