To run Nortantis you must have Java 8 or later installed. If you don't already have it installed, you can find it here.
Your computer must have at least 3 GB of RAM memory.
Get the latest version of Nortantis here.
The download above gives you a zip file containing an executable jar file and a folder of assets such as mountain and tree icons. The way to run Nortantis depends on your operating system:
Generating a map requires some intense computing, so it can take up to a minute depending on the speed of your computer and the size of the map you generate.
If you want to generate maps at higher resolutions than the default, you must first modify run.bat (or run.bash for Linux) to increase the amount of memory Nortantis can use. Find -Xmx1G and change the 1 to the number of gigabytes to use. For example, to use 8 GBs it should be -Xmx8G. When Nortantis opens it checks the amount of RAM allocated and adjusts the maximum on the "Resolution" slider in the "Background" tab to the maximum size of map you can generate with that amount of RAM.
Nortantis is built on top of a polygon-based island generator by Red Blog games (here). It also uses several other open source libraries, one of the most important of which is JTransforms, which is used to do very fast image transformations.
Nortantis has the ability to generate random background images of arbitrary sizes based on a texture image. To do this, I used step 2 of the algorithm in section C from Random Phase Textures: Theory and Synthesis by Bruno Galerne et al. I used my own methods instead of steps 1 and 3. I also generate in multiple color channels like they do.