Generating World

Table of contents

  1. Initial generation
    1. Azgaar’s Fantasy Map Generator
      1. Heightmap
      2. Rivers
      3. Biomes
    2. Other
  2. World Painter
    1. Heightmap

Initial generation

Automatically getting awsome terrain requires generating heightmaps using tools like Gaea or World Machine. These are however commercial products (although limited use non-commercial is possible as well, for instance World Machine provides all the capabilities but limits the size to around 1024x1024). However, I prefer to use Azgaar’s Fantasy Map Generator.

Azgaar’s Fantasy Map Generator

This online tool is free and open source. It also has the capability to generate heightmaps, but these are not as nice-looking as they are intended for general, full world representations. But it has a few features that I like to combine with World Painter:

  • It generates biomes, which I can export as image to use as a mask in World Painter.
  • It places rivers, which I can use as a reference
  • It places landmarks and cities/villages, which I can use as a reference to populate the world

Before generating a world through AFMG, go to Options and set the Canvas size to the size of the Minecraft world you want to generate. Then, generate a new world. While you might not be able to view the entire world through AFMG (there is no “zoom out” option that I know of), you can generate it completely later.

Next, we generate the necessary views…

Heightmap

The first part is the heightmap. Select heightmap in the tool, and deselect all other options (like rivers). Then, in the Styles menu:

  • select Monochrome for style preset
  • select Coastline and write down the color value (usually 1F3846). Set the opacity then to 0. Without this setting, the coastline will generate with an abrupt wall.
  • select Ocean element and set the color to the previously written down value (or clear it out completely and fit later in WorldPainter). We want the ocean to be relatively flat in the output so that we can easily adjust this in World Painter later.
  • select Landmass element and set the fill to the previously written down value. Again, this is to make sure we do not get abrupt walls as edges.
  • select Lakes element and set the Opacity to 0 for each lake type.
  • select Heightmap element and set Reduce layers to 0, and Filter to Blur 5 or Blur 7.

The blurring reduces the terracing you get, but also makes the generated landscape less interesting (more boring) so requires a bit more work in World Painter.

To export the heightmap, export as SVG. Then, convert the SVG to a PNG file. For instance, with Inkscape:

~$ inkscape heightmap.svg -o heightmap.png

Rivers

Next, I export the rivers. Now, this will not be a mask that we can immediately convert into a river, but it gives a rough feeling where to place rivers.

  • Make sure only rivers are shown.
  • Go to Style and switch the Style preset to something else than Monochrome, and then set it back to Monochrome.
  • In Select elements, select Rivers.
    • Set Opacity to 1
    • Set Fill to white
    • Set Filter to None
  • In Select elements, select Ocean.
    • Set Color to black
    • Set Pattern to No pattern

Export as SVG, then convert to PNG. Next, make sure that the resulting PNG only has white or black:

~$ convert <source> -threshold %1 <destination>

Biomes

Next, I export the biomes as a color map. This cannot always be used as a mask though, as the number of annotation colors in WorldPainter is not matching the number of biomes that can be generated. But for a quick, first-pass biome allocation, this works just fine.

  • In Layers, select Biomes map, and make sure only Biomes are rendered.
  • In Style, use default as Style preset
  • For the Ocean element
    • Set Pattern opacity to 0
    • Set Color to black

When trying to generate masks, try to limit the number of colors:

~$ convert <source> -posterize 3 <target>

With ImageMagick, counting the number of colors is done like so:

~$ identify -format "%k" <source>

You can also remap colors to the colors in another image. I have an image that contains the 15 annotation colors:

~$ convert <source> -dither None -remap worldpainter_colormap.gif <target>

However, I have not yet found a way to force a remapping even when the target color is not close to the source.

Other

Other exports can be made as well. I recommend to have each item as a separate export, as that might occasionally result in usable masks.

For instance, you can select the routes (and remove trails) and export for a mask, allowing to easily generate roads on the map.

World Painter

When loading the map in World Painter, an important aspect is to keep away from terrain materials as long as possible, and instead use biomes and annotations.

But before this is done, let’s first load the map from the heightmap.

Heightmap

Use Import new world and then from heightmap.

I tend to use a custom world height, from -128 to 320. The water level is then set at 0. To load the heightmap itself, I generally map the highest value of the heightmap to around 120. This gives me leeway to generate the mountains, hills and plateaus through WorldPainter, and also reduces the number of artefacts that are loaded in from the heightmap.

The mapping for the lowest level is somewhat done on sight, making sure that the beach gets at the right level.

To regenerate the world, following the next steps can be used manually.

I use a script to apply this (polystruct-AutoRegenerate.js).

First, use the default theme generation (Ctrl+G, and select reset terrain and layers to theme).

Then apply the Hills custom terrain:

  • Use fill with terrain type
  • Select Hills (custom terrain)
  • Apply at or above 1
  • Apply at or below 90
  • Apply above 35 degrees
  • Do not apply feathering as it will corrupt beaches and ocean edges.

Apply the Rocky custom terrain:

  • Use the fill with terrain type
  • Select Rocky (custom terrain)
  • Apply at or above 1
  • Apply at or below 140
  • Apply above 45 degrees

Apply the snow layers: