There are two native modules that can greatly accelerate the process of generating terrain. One module is designed to generate the river network. The other is designed to compute the elevations of terrain primitives. Both modules use OpenMP to perform their computations in parallel, and both must be compiled. They were developed on Fedora and have been tested on Ubuntu. In the src directory, use make buildRivers and make terrainPrimitives to build the module, and use the --accelerate flag to use them.

Dependencies for the native module

To compile the module, you will need the OpenCV library and the necessary header files. On Ubuntu (and hopefully other Debian-based systems), you can use

apt install libopencv-dev apt install libgeos-dev

On Fedora and RPM-based distributions, these commands should suffice

dnf install opencv-devel dnf install geos-devel

You will also need OpenMP. It seems to come with Ubuntu and Fedora, but it's also widely available in package repositories.