iCartographer will randomly generate maps using fractal algorithms. In the future, I hope to allow it to support more user-input to create the maps. The documentation here was written for version 0.1.3a.

Types of Maps

There are three different types of maps, each projected onto a different surface.

Flatland: This is not truly a two dimensional space à la the story. This is basically a square with the map on its surface. Because it is a euclidian surface, there is no distortion for distance in any area. This type of map is generated with a midpoint displacement method.

Cylinder: This is very similar to a flatland, but it is twice as wide and the left and right sides wrap around to each other. Once again, it is a euclidian surface and there is no distortion. This type of map is generated with a midpoint displacement method.

Sphere: This is equivalent to the world maps we know and love. This map could be placed on a globe. It is non-euclidian, so there is distortion which increases as one approaches the poles. This type of map is generated with the random slice approach.

New Maps

The chief way to create a map is to use the "New" or "New With Options…" command. The default "New" command will create a cylinder map. It is very quick to generate and creates interesting maps while still maintaining a semi-approximation of a sphere. If you choose "New With Options…" will bring up the "New Planet" window and allow a chance to select the type of surface you wish to have generated.

All maps will be scaled to a range of 20,000 metres between the highest point and the lowest point. This number was chosen because Mount Everest, the highest point on Earth, has an elevation of 8,848 metres and the Mariana Trench, the lowest point on earth, is 10,911 metres deep. This is a difference of 19,759 metres, which was rounded off to 20,000.

In actuality this has very little bearing on the maps created in this application and the numbers can be treated as arbitrary. The only thing affected by this designation is when defining sea level. However, it should be pointed out that the algorithm involved in generating the world will automatically create mountainous terrain everywhere. This is not true in the real world, but unless one knows the elevation of each point, it will still appear plausibly real.

By default, new maps have a surface covered with a percentage of water. Presently, the target percentage is 68.9767%. This number was obtained because 71.11% of the earth is covered in water, but 3% of that is freshwater. 97% of 71.11% is 68.9767%. However, the source of this information is not completely trustworthy.

If you have an area selected on an existing map, you can also create a new map with the "New From Selection" option. This will always create a flatland map.

Once you have a map you like you can save it to disk with a .icart file extension.

Existing Maps

You can open existing .icart files, and you can also open the files created by the Shuttle Radar Topography Mission. These can be downloaded from the official site. Once downloaded and uncompressed, they will be read in as flatlands. Each file contains a one degree by one degree section of the earth's surface and is named by the coordinate's of it's south-west corner. The name of the file is used by iCartographer to determine the scale used.

Exploring Maps

There are a number of tools to let you explore your map.


You can select areas of the map by clicking and dragging the mouse. On euclidian maps (flatland and cylinders) you select one corner and drag to the opposite one. On non-euclidian (spheres) the initial point selected is treated as the centre and the size increases the further away the mouse is dragged.


Aside from the scroll bars, if you hold down the command key while clicking and dragging the mouse, then the map will scroll around.


From the "View" menu there are two menu items for controlling the current zoom on the map: "Zoom In" and "Zoom Out". These change how much detail you can see on the map. If you zoom in a lot, you may want to increase the granularity.

Manipulating Maps

There are two types of manipulation that can be done, visual or physical. A visual change does not change the underlying map, but merely changes how it looks. A physical change is actually changing the properties of the map.

Visual Manipulations

Visual manipulation is presently confined to two options: colours and relief. The colours that are displayed are controlled in the "Elevation Colours Panel". Relief is controlled by the relief button on the top left of the map window. If it is activated, the land is shaded to simulate the casting of shadows.

Physical Manipulations

At present, the only physical manipulations that can be done are to affect the water, change the elevations to match Terra (AKA Earth) and increase the granularity. The first two can all be accessed from the Elevation Panel which is described later. The last can be done from the Map menu item, "Increase Granularity". This command will increase the details of a given map. A fractal algorithm is used to add the details, which amount to doubling the length and width of the map.

Elevation Panel

The elevation panel is the chief way to control the seas on a map.

At the top of the window is the option whether to have any water appear at all.

Below that is the "Sea Level Controller". This is chiefly a sliding scale that controls what the sea level is. The higher the sea level is, the more of the map will be covered by water. The scale is in metres, because only third world countries use the Imperial system. (I'm looking at you, Liberia!)

If you want more precision than the scale provides, there is a text box where one can type in the exact sea level they wish. However, this must be in the range between the highest and lowest points on the map.

At the bottom of the panel is a percentage listing the current ocean coverage on the map.

To the right is a hypsograph (elevation histogram) of the current map. It will give you a broad idea of what the average elevation on the map is.

Beneath that is a button labelled "Match Earth Elevations". When clicked, this will modify the topography of the map to match Terran averages. The sea-level will not be changed, but the distribution of all terrain above sea level on the map will match the distribution of all terrain above sea level on Terra. The same is true for the surface beneath the sea. The highest point will be roughly the same as Mount Everest and the lowest will match the Mariana Trench.

Elevation Colour Panel

This is the chief way to control the colours that appear on maps. Simply choose the colour scheme that should be used for the map.