The Elevation Map Tab

This tab is where we decide the elevation of each map tile.
Elevation Tab Screenshot

The Zoom Level control will zoom in all maps associated with this tab. Zooming in will change the size of the edit brush so that the edit reticle cursor always shows the extent of the brushes effect.

The ‘Preview Small Oceans Filled’ check box allows you to see what the map will look like once the oceans below a certain size are filled. The reason that this feature is usually off is because filling the lakes changes the sea level, which can create more lakes that need to be filled, which again changes the sea level, which again creates… well, you get the idea. It’s better to keep it off until the last step where you can have a last look to see what the result will be.

The ‘Fill In Oceans Smaller Than’ control sets the size at which lakes are filled. The reason why you want to fill small lakes is because they are treated as saltwater oceans by the game, and any rivers that flow into these small lakes end. It looks very awkward to have all the world’s major rivers empty into a 1 tile itty-bitty ocean, so to avoid that scenario, we fill in the small oceans. A setting of 0 will disable this feature and allow any size ocean.

The ‘Percent Below Sea Level’ slider allows you to set the elevation that below which is underwater and considered ocean tiles.

The ‘Percent Below Tree Line’ slider allows you to set the elevation that below which are your normal land biomes, and above which are considered mountains. The mountains will be eroded in game depending on how many erosion cycles you have chosen in the world_gen.txt parameters, so here you would set them to a slightly higher amount to compensate.

The ‘Coast Control’ buttons allow you to force coast or a mountain border on any of the map edges and to create an inland sea. In order to avoid squarish looking coasts, you might raise the sea level if you use these so you can create a natural looking coastline.

The elevation map is created by combining two different Perlin noise fields. One is called a ‘turbulence’ field and the other can be either normal Perlin noise or also turbulence. Turbulence is created from noise by inverting values above the middle range. This creates a cusp of high values that can look like spaghetti or a mountain range depending on how you look at it. Turbulence has the advantage that it can be used to simulate mountain ranges, but because all of the highest values run a spaghetti like path, it is not suitable to create islands. For a regional map you will often use the turbulence map to create mountain ranges, and the second noise field to create details. If you desire to create a map of islands or continents upon an ocean, you would reverse their roles. You would use the second noise map with normal noise to create islands, and then use the turbulence map to create details. Have a look at these two screenshots and compare the settings on each.
Region Map ScreenshotIsland Map Screenshot

(Curious Note: If you look at the upper left corners of the two turbulence fields in the above examples you might notice that they are using the same noise field, but with a different size and smoothness. Fun!)

Each noise field has it’s own set of similar controls.

The ‘weight’ slider governs how much of this noise map is added to the final elevation map. Setting both noise maps to zero weight will remove them from the final map and cause only any map edits you have made to be visible.

The ‘Feature Size’ slider adjusts the size of the features in the noise field. The higher the number, the smaller the features get. If that seems awkward, the slider is actually controlling ‘frequency’ directly, and size indirectly as a result of frequency.

The ‘Smoothness’ slider adjusts the smoothness of the noise field.

The ‘Generate New’ buttons scramble the noise inputs to create a new noise field.

You may also click and drag on the noise fields to adjust their position in case you want a certain feature to appear in a specific location.

New for 1.01:

New Controls for 1.01

As of version 1.01 the coast buttons create coast and also mountain borders. Also, you may import a greyscale bitmap in *.bmp or *.png file format for your elevations. The filter is used to smooth your hand drawn imported bitmaps. Set the filter to a slightly larger size than the brush you used to paint the image. The imported bitmap may be blended with the other noise maps as desired using the weight controls on the noise maps.