Alpine Map: How does it get created?

How do we get to the following map? Reload to get a different one. If you like this particular map, bookmark this link, and edit it using this link,

01.01 01.02 01.03 01.04 01.05 02.01 02.02 02.03 02.04 02.05 03.01 03.02 03.03 03.04 03.05 04.01 04.02 04.03 04.04 04.05 05.01 05.02 05.03 05.04 05.05 06.01 06.02 06.03 06.04 06.05 07.01 07.02 07.03 07.04 07.05 08.01 08.02 08.03 08.04 08.05 09.01 09.02 09.03 09.04 09.05 10.01 10.02 10.03 10.04 10.05 11.01 11.02 11.03 11.04 11.05 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 14.01 14.02 14.03 14.04 14.05 15.01 15.02 15.03 15.04 15.05 16.01 16.02 16.03 16.04 16.05 17.01 17.02 17.03 17.04 17.05 18.01 18.02 18.03 18.04 18.05 19.01 19.02 19.03 19.04 19.05 20.01 20.02 20.03 20.04 20.05 Gnomeyland SVG Map Icons Copyright Gregory B. MacKenzie 2012, Alex Schroeder 2013-2016. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

First, we pick a number of peaks and set their altitude to 10. Then we loop through all the altitudes from 10 down to 1 and for every hex we added in the previous run, we add three neighbors at a lower altitude, if possible. If our random growth missed any hexes, we just copy the height of a neighbor. If we can't find a suitable neighbor within a few tries, just make a hole in the ground (altitude 0).

01.01 01.02 01.03 01.04 01.05 02.01 02.02 02.03 02.04 02.05 03.01 03.02 03.03 03.04 03.05 04.01 04.02 04.03 04.04 04.05 05.01 05.02 05.03 05.04 05.05 06.01 06.02 06.03 06.04 06.05 07.01 07.02 07.03 07.04 07.05 08.01 08.02 08.03 08.04 08.05 09.01 09.02 09.03 09.04 09.05 10.01 10.02 10.03 10.04 10.05 11.01 11.02 11.03 11.04 11.05 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 14.01 14.02 14.03 14.04 14.05 15.01 15.02 15.03 15.04 15.05 16.01 16.02 16.03 16.04 16.05 17.01 17.02 17.03 17.04 17.05 18.01 18.02 18.03 18.04 18.05 19.01 19.02 19.03 19.04 19.05 20.01 20.02 20.03 20.04 20.05 55 66 77 88 99 66 77 77 88 1010 66 77 88 88 99 77 88 99 1010 99 66 77 88 99 88 66 77 88 88 77 55 66 77 77 77 55 66 66 66 66 55 66 77 77 77 66 77 88 88 66 66 77 88 99 99 77 88 99 1010 66 66 88 99 88 77 99 1010 88 77 66 88 99 77 77 77 88 88 88 88 88 77 77 77 99 99 66 77 88 1010 99 55 66 77 77 88 55 66 66 77 77 Gnomeyland SVG Map Icons Copyright Gregory B. MacKenzie 2012, Alex Schroeder 2013-2016. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

Mountains are the hexes at high altitudes: white mountains (altitude 10), white mountain (altitude 9), light-grey mountain (altitude 8).

01.01 01.02 01.03 01.04 01.05 02.01 02.02 02.03 02.04 02.05 03.01 03.02 03.03 03.04 03.05 04.01 04.02 04.03 04.04 04.05 05.01 05.02 05.03 05.04 05.05 06.01 06.02 06.03 06.04 06.05 07.01 07.02 07.03 07.04 07.05 08.01 08.02 08.03 08.04 08.05 09.01 09.02 09.03 09.04 09.05 10.01 10.02 10.03 10.04 10.05 11.01 11.02 11.03 11.04 11.05 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 14.01 14.02 14.03 14.04 14.05 15.01 15.02 15.03 15.04 15.05 16.01 16.02 16.03 16.04 16.05 17.01 17.02 17.03 17.04 17.05 18.01 18.02 18.03 18.04 18.05 19.01 19.02 19.03 19.04 19.05 20.01 20.02 20.03 20.04 20.05 55 66 77 88 99 66 77 77 88 1010 66 77 88 88 99 77 88 99 1010 99 66 77 88 99 88 66 77 88 88 77 55 66 77 77 77 55 66 66 66 66 55 66 77 77 77 66 77 88 88 66 66 77 88 99 99 77 88 99 1010 66 66 88 99 88 77 99 1010 88 77 66 88 99 77 77 77 88 88 88 88 88 77 77 77 99 99 66 77 88 1010 99 55 66 77 77 88 55 66 66 77 77 Gnomeyland SVG Map Icons Copyright Gregory B. MacKenzie 2012, Alex Schroeder 2013-2016. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

We determine the flow of water by having water flow to one of the lowest neighbors if possible. Water doesn't flow upward, and if there is already water coming our way, then it won't flow back. It has reached a dead end.

01.01 01.02 01.03 01.04 01.05 02.01 02.02 02.03 02.04 02.05 03.01 03.02 03.03 03.04 03.05 04.01 04.02 04.03 04.04 04.05 05.01 05.02 05.03 05.04 05.05 06.01 06.02 06.03 06.04 06.05 07.01 07.02 07.03 07.04 07.05 08.01 08.02 08.03 08.04 08.05 09.01 09.02 09.03 09.04 09.05 10.01 10.02 10.03 10.04 10.05 11.01 11.02 11.03 11.04 11.05 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 14.01 14.02 14.03 14.04 14.05 15.01 15.02 15.03 15.04 15.05 16.01 16.02 16.03 16.04 16.05 17.01 17.02 17.03 17.04 17.05 18.01 18.02 18.03 18.04 18.05 19.01 19.02 19.03 19.04 19.05 20.01 20.02 20.03 20.04 20.05 55 66 77 88 99 66 77 77 88 1010 66 77 88 88 99 77 88 99 1010 99 66 77 88 99 88 66 77 88 88 77 55 66 77 77 77 55 66 66 66 66 55 66 77 77 77 66 77 88 88 66 66 77 88 99 99 77 88 99 1010 66 66 88 99 88 77 99 1010 88 77 66 88 99 77 77 77 88 88 88 88 88 77 77 77 99 99 66 77 88 1010 99 55 66 77 77 88 55 66 66 77 77 Gnomeyland SVG Map Icons Copyright Gregory B. MacKenzie 2012, Alex Schroeder 2013-2016. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

Any of the dead ends we found in the previous step are marked as lakes.

01.01 01.02 01.03 01.04 01.05 02.01 02.02 02.03 02.04 02.05 03.01 03.02 03.03 03.04 03.05 04.01 04.02 04.03 04.04 04.05 05.01 05.02 05.03 05.04 05.05 06.01 06.02 06.03 06.04 06.05 07.01 07.02 07.03 07.04 07.05 08.01 08.02 08.03 08.04 08.05 09.01 09.02 09.03 09.04 09.05 10.01 10.02 10.03 10.04 10.05 11.01 11.02 11.03 11.04 11.05 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 14.01 14.02 14.03 14.04 14.05 15.01 15.02 15.03 15.04 15.05 16.01 16.02 16.03 16.04 16.05 17.01 17.02 17.03 17.04 17.05 18.01 18.02 18.03 18.04 18.05 19.01 19.02 19.03 19.04 19.05 20.01 20.02 20.03 20.04 20.05 55 66 77 88 99 66 77 77 88 1010 66 77 88 88 99 77 88 99 1010 99 66 77 88 99 88 66 77 88 88 77 55 66 77 77 77 55 66 66 66 66 55 66 77 77 77 66 77 88 88 66 66 77 88 99 99 77 88 99 1010 66 66 88 99 88 77 99 1010 88 77 66 88 99 77 77 77 88 88 88 88 88 77 77 77 99 99 66 77 88 1010 99 55 66 77 77 88 55 66 66 77 77 Gnomeyland SVG Map Icons Copyright Gregory B. MacKenzie 2012, Alex Schroeder 2013-2016. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

Any hex that flows towards a neighbor at the same altitude is insufficiently drained. These are marked as swamps. The background color of the swamp depends on the altitude: light-grey (altitude 8 and higher), grey (altitude 6–7), dark-grey (altitude 5 and lower).

01.01 01.02 01.03 01.04 01.05 02.01 02.02 02.03 02.04 02.05 03.01 03.02 03.03 03.04 03.05 04.01 04.02 04.03 04.04 04.05 05.01 05.02 05.03 05.04 05.05 06.01 06.02 06.03 06.04 06.05 07.01 07.02 07.03 07.04 07.05 08.01 08.02 08.03 08.04 08.05 09.01 09.02 09.03 09.04 09.05 10.01 10.02 10.03 10.04 10.05 11.01 11.02 11.03 11.04 11.05 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 14.01 14.02 14.03 14.04 14.05 15.01 15.02 15.03 15.04 15.05 16.01 16.02 16.03 16.04 16.05 17.01 17.02 17.03 17.04 17.05 18.01 18.02 18.03 18.04 18.05 19.01 19.02 19.03 19.04 19.05 20.01 20.02 20.03 20.04 20.05 55 66 77 88 99 66 77 77 88 1010 66 77 88 88 99 77 88 99 1010 99 66 77 88 99 88 66 77 88 88 77 55 66 77 77 77 55 66 66 66 66 55 66 77 77 77 66 77 88 88 66 66 77 88 99 99 77 88 99 1010 66 66 88 99 88 77 99 1010 88 77 66 88 99 77 77 77 88 88 88 88 88 77 77 77 99 99 66 77 88 1010 99 55 66 77 77 88 55 66 66 77 77 Gnomeyland SVG Map Icons Copyright Gregory B. MacKenzie 2012, Alex Schroeder 2013-2016. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

We still need to figure out how to drain lakes. In order to do that, we start "flooding" lakes, looking for a way to the edge of the map. If we're lucky, our search will soon hit upon a sequence of arrows that leads to ever lower altitudes and to the edge of the map. An outlet! We start with all the hexes that don't have an arrow. For each one of those, we look its neighbors. These are our initial candidates. We keep expanding our list of candidates as we add at neighbors of neighbors. At every step we prefer the lowest of these candidates. Once we have reached the edge of the map, we backtrack and change any arrows pointing the wrong way.

01.01 01.02 01.03 01.04 01.05 02.01 02.02 02.03 02.04 02.05 03.01 03.02 03.03 03.04 03.05 04.01 04.02 04.03 04.04 04.05 05.01 05.02 05.03 05.04 05.05 06.01 06.02 06.03 06.04 06.05 07.01 07.02 07.03 07.04 07.05 08.01 08.02 08.03 08.04 08.05 09.01 09.02 09.03 09.04 09.05 10.01 10.02 10.03 10.04 10.05 11.01 11.02 11.03 11.04 11.05 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 14.01 14.02 14.03 14.04 14.05 15.01 15.02 15.03 15.04 15.05 16.01 16.02 16.03 16.04 16.05 17.01 17.02 17.03 17.04 17.05 18.01 18.02 18.03 18.04 18.05 19.01 19.02 19.03 19.04 19.05 20.01 20.02 20.03 20.04 20.05 55 66 77 88 99 66 77 77 88 1010 66 77 88 88 99 77 88 99 1010 99 66 77 88 99 88 66 77 88 88 77 55 66 77 77 77 55 66 66 66 66 55 66 77 77 77 66 77 88 88 66 66 77 88 99 99 77 88 99 1010 66 66 88 99 88 77 99 1010 88 77 66 88 99 77 77 77 88 88 88 88 88 77 77 77 99 99 66 77 88 1010 99 55 66 77 77 88 55 66 66 77 77 Gnomeyland SVG Map Icons Copyright Gregory B. MacKenzie 2012, Alex Schroeder 2013-2016. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

We add a river sources high up in the mountains (altitudes 7 and 8), merging them as appropriate. These rivers flow as indicated by the arrows. If the river source is not a mountain (altitude 8) or a swamp, then we place a forested hill at the source (thus, they're all at altitude 7).

01.01 01.02 01.03 01.04 01.05 02.01 02.02 02.03 02.04 02.05 03.01 03.02 03.03 03.04 03.05 04.01 04.02 04.03 04.04 04.05 05.01 05.02 05.03 05.04 05.05 06.01 06.02 06.03 06.04 06.05 07.01 07.02 07.03 07.04 07.05 08.01 08.02 08.03 08.04 08.05 09.01 09.02 09.03 09.04 09.05 10.01 10.02 10.03 10.04 10.05 11.01 11.02 11.03 11.04 11.05 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 14.01 14.02 14.03 14.04 14.05 15.01 15.02 15.03 15.04 15.05 16.01 16.02 16.03 16.04 16.05 17.01 17.02 17.03 17.04 17.05 18.01 18.02 18.03 18.04 18.05 19.01 19.02 19.03 19.04 19.05 20.01 20.02 20.03 20.04 20.05 55 66 77 88 99 66 77 77 88 1010 66 77 88 88 99 77 88 99 1010 99 66 77 88 99 88 66 77 88 88 77 55 66 77 77 77 55 66 66 66 66 55 66 77 77 77 66 77 88 88 66 66 77 88 99 99 77 88 99 1010 66 66 88 99 88 77 99 1010 88 77 66 88 99 77 77 77 88 88 88 88 88 77 77 77 99 99 66 77 88 1010 99 55 66 77 77 88 55 66 66 77 77 Gnomeyland SVG Map Icons Copyright Gregory B. MacKenzie 2012, Alex Schroeder 2013-2016. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

Remember how the arrows were changed at some points such that rivers don't always flow downwards. We're going to assume that in these situations, the rivers have cut canyons into the higher lying ground and we'll add a little shadow.

01.01 01.02 01.03 01.04 01.05 02.01 02.02 02.03 02.04 02.05 03.01 03.02 03.03 03.04 03.05 04.01 04.02 04.03 04.04 04.05 05.01 05.02 05.03 05.04 05.05 06.01 06.02 06.03 06.04 06.05 07.01 07.02 07.03 07.04 07.05 08.01 08.02 08.03 08.04 08.05 09.01 09.02 09.03 09.04 09.05 10.01 10.02 10.03 10.04 10.05 11.01 11.02 11.03 11.04 11.05 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 14.01 14.02 14.03 14.04 14.05 15.01 15.02 15.03 15.04 15.05 16.01 16.02 16.03 16.04 16.05 17.01 17.02 17.03 17.04 17.05 18.01 18.02 18.03 18.04 18.05 19.01 19.02 19.03 19.04 19.05 20.01 20.02 20.03 20.04 20.05 55 66 77 88 99 66 77 77 88 1010 66 77 88 88 99 77 88 99 1010 99 66 77 88 99 88 66 77 88 88 77 55 66 77 77 77 55 66 66 66 66 55 66 77 77 77 66 77 88 88 66 66 77 88 99 99 77 88 99 1010 66 66 88 99 88 77 99 1010 88 77 66 88 99 77 77 77 88 88 88 88 88 77 77 77 99 99 66 77 88 1010 99 55 66 77 77 88 55 66 66 77 77 Gnomeyland SVG Map Icons Copyright Gregory B. MacKenzie 2012, Alex Schroeder 2013-2016. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

Wherever there is water and no swamp, forests will form. The exact type again depends on the altitude: light green fir-forest (altitude 6 and higher), green forest (altitude 4–5), dark-green forest (altitude 3 and lower).

01.01 01.02 01.03 01.04 01.05 02.01 02.02 02.03 02.04 02.05 03.01 03.02 03.03 03.04 03.05 04.01 04.02 04.03 04.04 04.05 05.01 05.02 05.03 05.04 05.05 06.01 06.02 06.03 06.04 06.05 07.01 07.02 07.03 07.04 07.05 08.01 08.02 08.03 08.04 08.05 09.01 09.02 09.03 09.04 09.05 10.01 10.02 10.03 10.04 10.05 11.01 11.02 11.03 11.04 11.05 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 14.01 14.02 14.03 14.04 14.05 15.01 15.02 15.03 15.04 15.05 16.01 16.02 16.03 16.04 16.05 17.01 17.02 17.03 17.04 17.05 18.01 18.02 18.03 18.04 18.05 19.01 19.02 19.03 19.04 19.05 20.01 20.02 20.03 20.04 20.05 55 66 77 88 99 66 77 77 88 1010 66 77 88 88 99 77 88 99 1010 99 66 77 88 99 88 66 77 88 88 77 55 66 77 77 77 55 66 66 66 66 55 66 77 77 77 66 77 88 88 66 66 77 88 99 99 77 88 99 1010 66 66 88 99 88 77 99 1010 88 77 66 88 99 77 77 77 88 88 88 88 88 77 77 77 99 99 66 77 88 1010 99 55 66 77 77 88 55 66 66 77 77 Gnomeyland SVG Map Icons Copyright Gregory B. MacKenzie 2012, Alex Schroeder 2013-2016. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

Any remaining hexes have no river flowing through them and are considered to be little more arid. They get bushes. Higher up, these are light grey (altitude 7), otherwise they are light green (altitude 6 and below).

. 01.01 01.02 01.03 01.04 01.05 02.01 02.02 02.03 02.04 02.05 03.01 03.02 03.03 03.04 03.05 04.01 04.02 04.03 04.04 04.05 05.01 05.02 05.03 05.04 05.05 06.01 06.02 06.03 06.04 06.05 07.01 07.02 07.03 07.04 07.05 08.01 08.02 08.03 08.04 08.05 09.01 09.02 09.03 09.04 09.05 10.01 10.02 10.03 10.04 10.05 11.01 11.02 11.03 11.04 11.05 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 14.01 14.02 14.03 14.04 14.05 15.01 15.02 15.03 15.04 15.05 16.01 16.02 16.03 16.04 16.05 17.01 17.02 17.03 17.04 17.05 18.01 18.02 18.03 18.04 18.05 19.01 19.02 19.03 19.04 19.05 20.01 20.02 20.03 20.04 20.05 55 66 77 88 99 66 77 77 88 1010 66 77 88 88 99 77 88 99 1010 99 66 77 88 99 88 66 77 88 88 77 55 66 77 77 77 55 66 66 66 66 55 66 77 77 77 66 77 88 88 66 66 77 88 99 99 77 88 99 1010 66 66 88 99 88 77 99 1010 88 77 66 88 99 77 77 77 88 88 88 88 88 77 77 77 99 99 66 77 88 1010 99 55 66 77 77 88 55 66 66 77 77 Gnomeyland SVG Map Icons Copyright Gregory B. MacKenzie 2012, Alex Schroeder 2013-2016. This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

Cliffs form wherever the drop is more than just one level of altitude.

01.01 01.02 01.03 01.04 01.05 02.01 02.02 02.03 02.04 02.05 03.01 03.02 03.03 03.04 03.05 04.01 04.02 04.03 04.04 04.05 05.01 05.02 05.03 05.04 05.05 06.01 06.02 06.03 06.04 06.05 07.01 07.02 07.03 07.04 07.05 08.01 08.02 08.03 08.04 08.05 09.01 09.02 09.03 09.04 09.05 10.01 10.02 10.03 10.04 10.05 11.01 11.02 11.03 11.04 11.05 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 14.01 14.02 14.03 14.04 14.05 15.01 15.02 15.03 15.04 15.05 16.01 16.02 16.03 16.04 16.05 17.01 17.02 17.03 17.04 17.05 18.01 18.02 18.03 18.04 18.05 19.01 19.02 19.03 19.04 19.05 20.01 20.02 20.03 20.04 20.05 55 66 77 88 99 66 77 77 88 1010 66 77 88 88 99 77 88 99 1010 99 66 77 88 99 88 66 77 88 88 77 55 66 77 77 77 55 66 66 66 66 55 66 77 77 77 66 77 88 88 66 66 77 88 99 99 77 88 99 1010 66 66 88 99 88 77 99 1010 88 77 66 88 99 77 77 77 88 8