Resources: spread functions

🚧 Under construction

Resource spread models are applied to check whether resource can or cannot be placed in a cell. Fantasy Map Generator allows to create custom spread models, but it requires some understanding on how models work. Resources are generated before states and cultures, so models are built on top of geographical data. Once model is changed, you need to regenerate all resources.

Technical info

Technically spread models are expressions evaluated for each cell to return true or false. If true is returned, the resource can be placed in the cell. The expressions are valid JS functions, you can use logical operators (! for not, || for OR, && for and, etc.) and other features.

The options are limited to a number of build-in functions. These functions make models syntax easier to read and write:

• random(number): percentage of true, e.g. 50 will return true in 50% of cases
• nth(number): true for each nth cell only, e.g. nth(2) skips 50% of cells, nth(5) skips 80% of cells
• habitable(): true if biome habitability is greater than 0
• habitability(): check against biome habitability. Always true for habitability >=100, false for 0, skips 50% of cells if habitability is 50 and so on
• elevation(): check against cell's height - the higher cell is, the greater chance is. If you need resource to be more frequent in lower elevation areas, than just negate the function: !elevation()
• biome(biomeId, biomeId, ...): check against list of biome ids, see below to get biome id reference
• minHeight(number): true if cell height >= number. Number is in range [0-100], where 0 is deep ocean and 20 is minimal land elevation
• maxHeight(number): true if cell height <= number
• minTemp(number): true if cell temperature (in Celsius) >= number
• maxTemp(number): true if cell temperature <= number
• shore(ringId, ringId, ...): check against cell distance to shore, where 1 is land next to water (coastline cells), 2 - next land ring, -1 - water cells next to land (shallow water), -2, -3, ... - next water rings, 0 - value not assigned, usually values are assigned only for first 2 land rings, so other land cells have zero value
• type(string, string, ...): check against cell type. Types of all water cells connected to map border is ocean, lake types are freshwater, salt, sinkhole, frozen, lava and dry. Land types are defined not so clear, so I don't recommend to use them. In any case land types are continent, island, isle and lake_island
• river(): true if there is a river in the cell

Examples

Let's say we want a resource to be generated in hot and highly elevated areas. If altitude is medium, let it also be allowed, but pretty rarely. The model will be something like minTemp(15) && (minHeight(70) || minHeight(40) && nth(5)).

Another usual case is when we want resource frequency vary based on biomes. In this case you need to join multiple biome() functions like biome(1) && (biome(2) && nth(2)) && (biome(3) && nth(3)).

Check the build-in function below to get the gist.

Built-in models

• Deciduous_forests: biome(6, 7, 8)
• Any_forest: biome(5, 6, 7, 8, 9)
• Temperate_and_boreal_forests: biome(6, 8, 9)
• Hills: minHeight(40) || (minHeight(30) && nth(10))
• Mountains: minHeight(60) || (minHeight(40) && nth(10))
• Mountains_and_wetlands: minHeight(60) || (biome(12) && nth(8))
• Headwaters: river() && minHeight(40)
• Biome_habitability: habitability()
• Marine_and_rivers: type("ocean", "freshwater", "salt") || (river() && shore(1, 2))
• Pastures_and_temperate_forest: (biome(3, 4) && !elevation()) || (biome(6) && random(70)) || (biome(5) && nth(5))
• Tropical_forests: biome(5, 7)
• Arid_land_and_salt_lakes: type("salt", "dry") || (biome(1, 2) && random(70)) || (biome(12) && nth(10))
• Hot_desert: biome(1)
• Deserts: biome(1, 2)
• Grassland_and_cold_desert: biome(3) || (biome(2) && nth(4))
• Hot_biomes: biome(1, 3, 5, 7)
• Hot_desert_and_tropical_forest: biome(1, 7)
• Tropical_rainforest: biome(7)
• Tropical_waters: shore(-1) && minTemp(18)
• Hilly_tropical_rainforest: minHeight(40) && biome(7)
• Subtropical_waters: shore(-1) && minTemp(14)
• Habitable_biome_or_marine: shore(-1) || habitable()
• Foresty_seashore: shore(1) && biome(6, 7, 8, 9)
• Boreal_forests: biome(9) || (biome(10) && nth(2)) || (biome(6, 8) && nth(5)) || (biome(12) && nth(10))
• Less_habitable_seashore: shore(1) && habitable() && !habitability()
• Less_habitable_biomes: habitable() && !habitability()
• Arctic_waters: biome(0) && maxTemp(7)

Biomes ids

Default biome ids:

• 0: Marine
• 1: Hot desert
• 2: Cold desert
• 3: Savanna
• 4: Grassland
• 5: Tropical seasonal forest
• 6: Temperate deciduous forest
• 7: Tropical rainforest
• 8: Temperate rainforest
• 9: Taiga
• 10: Tundra
• 11: Glacier
• 12: Wetland

To get actual biome id run biomesData.name.map((n,i) => i+". "+n) in FMG console (F12).