World Builder Procedures Analysis, Information, Question, and Answer Thread

[Dio]

This thread explores the actual calculations that occur within the world construction engine. This includes the influences that the options in the Alphax file and custom world have on these procedures.
The first area I intend to disclose covers the river creation formula. This section involves the world ocean percentage, the world rainfall selection (Cloud Cover), the river base from the Alphax File, and the river base modifier value from the alphax file. The world rainfall value ranges from 1 to 3, the world ocean value ranges from 0 to 2 (with 2 equaling the percentage of ocean as 70%-90% and 0 equaling 30%-50%), the river base range must fall within 0 through 100, and the river modifier value must fall within 0 to 100. This thread assumes that a player employs the default values from the alphax file, but this formula applies for any value that falls within the range given for each variable. The formula for the procedure to create rivers appears as follows: {[(River Rain Mod. * World Rainfall Selection) + River Base Value) * (4 - World Ocean Selection) * 0.6/ 2^31] * World Map Area (1/2 Map Width * Map Height) * 1,374,389,535 / 2^41}.
This means a standard sized world with 30-50% ocean and abundant cloud cover should have 24 rivers.

[Dio]

This post covers the hill creation formula. This procedure involves the World Erosive Forces Value (0, 1, 2), the world ocean selection value (0-2), the hills base value from alphax (0-100), and the hills modifier value from alphax (0-100). The formula appears as follows: {[(Hills Modifier * World Erosive Forces) + Hills Base Value] * World Area (Same as the above post: 1600 for a standard world) * 1,374,389,535 / 2^41}. If the world ocean coverage is 70%-90% (2), than divide this quotinent by 2 and round down towards the closest whole number. This means a standard sized world with weak erosive forces and the default values in alphax for hills should have 5 hills.

[Mart]

There is a thread, where Yitzi posted info on map format, let me find it and link it. Useful, when one wants to create a map or modify one outside of the game.
The link to the message:
http://alphacentauri2.info/index.php?topic=16376.msg71317#msg71317

[Dio]

This post explores the factors that influence the land creation. The values that factor into this procedure include the ocean selection value (0-2), the land base (50-4000), the continent modifier (0-2000), the islands value (1-500), and the world area (1600 on a standard sized world). The formula for this procedure appears as follows: {[(2- Ocean World Values) * Land Modifier + Land Base] * Map Area * 1,374,389,535/ 2^41}. This means on a standard world with 30%-50% ocean coverage the land base seed size should equal 896. The island formula appears as [(Island Value * World Area) * 1,374,389,535/2^41]. This means on a standard sized world the number of islands should equal 36.

[gwillybj]

This will be invaluable for  me, as I frequently make new huge (360x180) maps for my solo games. Thank for the information!