Advanced world generation - Revision history

Ziusudra: /* Interaction between Mesh Size and Weighted Ranges */ added ignore grid size for rectangular world

2026-04-15T02:42:06Z

Interaction between Mesh Size and Weighted Ranges: added ignore grid size for rectangular world

Ziusudra: /* Interaction between Mesh Size and Weighted Ranges */ added all weights at none

2026-04-15T01:53:27Z

Interaction between Mesh Size and Weighted Ranges: added all weights at none

Ziusudra: /* Interaction between Mesh Size and Weighted Ranges */ minor clarity tweaks

2026-04-10T05:41:09Z

Interaction between Mesh Size and Weighted Ranges: minor clarity tweaks

Ziusudra: /* Interaction between Mesh Size and Weighted Ranges */ missing word

2026-04-10T03:16:52Z

Interaction between Mesh Size and Weighted Ranges: missing word

Ziusudra: /* Interaction between Mesh Size and Weighted Ranges */ added non-square example

2026-04-10T03:08:01Z

Interaction between Mesh Size and Weighted Ranges: added non-square example

Ziusudra: /* Interaction between Mesh Size and Weighted Ranges */ expanded parenthetical about mesh size limits in UI

2026-04-10T02:46:01Z

Interaction between Mesh Size and Weighted Ranges: expanded parenthetical about mesh size limits in UI

Ziusudra: /* Terrain Mesh Sizes and Weights */ reworded bits in attempt to clarify and disambiguate, moved image up, changed redundant section name

2026-04-10T01:23:24Z

Terrain Mesh Sizes and Weights: reworded bits in attempt to clarify and disambiguate, moved image up, changed redundant section name

Ziusudra: /* Seed notes */ added DFHack command

2026-03-13T08:21:37Z

Seed notes: added DFHack command

96.242.227.107: /* Site cap after civ creation */ edited tower link to avoid disambiguation page and point to relevant page

2026-01-02T19:53:29Z

Site cap after civ creation: edited tower link to avoid disambiguation page and point to relevant page

Ziusudra: /* Number of Demon Types */ switched link to forum template

2025-12-17T04:00:27Z

Number of Demon Types: switched link to forum template

@@ Line 400: / Line 400: @@
 ==== Interaction between Mesh Size and Weighted Ranges ====
-Mesh size determines how many intersection points the world will have. As an example, setting it to 2×2 means the world will be divided into 4 areas, 2 across and 2 tall, and there will be a total of 9 intersection points (3×3). The grid intersection points are in the middle of world tiles, and the minimum size for a grid area is a span of 9 world tiles in either direction, with adjacent areas sharing an overlapping world tile. On a pocket world, this means one grid tile will span 9×9 world tiles, whereas on a large world, one grid tile will span 129×129 world tiles. A pocket world will always use a 2×2 grid of 9×9 world tiles, since it has only 17×17 tiles total (even if the game UI allows setting those worlds to a 4×4 grid, which can happen when changing the world size; changing the world size doesn't adjust mesh size limits, but saving then reloading the parameters does). A world that is 17 tiles wide, but 257 tall, and set to a 32×32 mesh size, will have 3×33 intersection points.
+Mesh size determines how many intersection points the world will have. As an example, setting it to 2×2 means the world will be divided into 4 areas, 2 across and 2 tall, and there will be a total of 9 intersection points (3×3), including the outer-most corners. The grid intersection points are in the middle of world tiles, and the minimum size for a grid area is a span of 9 world tiles in either direction, with adjacent areas sharing an overlapping world tile. On a pocket world, this means one grid tile will span 9×9 world tiles, whereas on a large world, one grid tile will span 129×129 world tiles. A pocket world will always use a 2×2 grid of 9×9 world tiles, since it has only 17×17 tiles total (even if the game UI allows setting those worlds to a 4×4 grid, which can happen when changing the world size; changing the world size doesn't adjust mesh size limits, but saving then reloading the parameters does). A world that is 17 tiles wide, but 257 tall, and set to a 32×32 mesh size, will have 3×33 intersection points.
-Setting mesh size to something other than Ignore, will apply random values at those intersections, with those random values being more likely to be in the ranges with higher weights. Setting to Ignore will cause the weighted range settings to be ignored for that terrain characteristic; instead setting the 4 corners of the world to completely random values and smoothing between those.
+Setting mesh size to something other than Ignore, will apply random values at those intersections, with those random values being more likely to be in the ranges with higher weights. Setting to Ignore will cause the weighted range settings to be ignored for that terrain characteristic; instead setting the 4 corners of the world to completely random values and smoothing between those, or in other words, using a 1×1 grid for square worlds; while for rectangular worlds, using the same ratio as the world dimensions with 1 in the narrow dimension (for example, a 1×16 grid for a 17×257 world).
 For example, if the Elevation Weighted Range parameters are set to <code>60:10:10:10:10</code> (starting with the 0-20 range, and these values do not need to add up to any particular number), and elevation min and max are left at the defaults of 1 and 400 respectively, then about 60% (on average) of the grid line intersection points will be set to an elevation in the range of 1-80 (0% to 20%), and the other ranges will be represented by around 10% of the intersection points each. The exact distribution is still left up to chance, though ''on average'' it will be close to this specification. This allows random number generation to be non-linear for the given terrain characteristic.

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 For example, if the Elevation Weighted Range parameters are set to <code>60:10:10:10:10</code> (starting with the 0-20 range, and these values do not need to add up to any particular number), and elevation min and max are left at the defaults of 1 and 400 respectively, then about 60% (on average) of the grid line intersection points will be set to an elevation in the range of 1-80 (0% to 20%), and the other ranges will be represented by around 10% of the intersection points each. The exact distribution is still left up to chance, though ''on average'' it will be close to this specification. This allows random number generation to be non-linear for the given terrain characteristic.
-Setting the weight for a range to None only prevents intersection points from being set to a value in that range; terrain between intersection points can still be smoothed to values in ranges set to None that are between the intersection point values.
+Setting the weight for a range to None only prevents intersection points from being set to a value in that range; terrain between intersection points can still be smoothed to values in ranges set to None that are between the intersection point values. Setting all the weights to None just puts them all at the same weight, the same as the default of all at 1.
 Weighted ranges do not make rejection checks, although they can be responsible for many rejections if you neglect to adjust or disable some of the [[#Minimum Number of Mid/Low/High Characteristic Squares|Minimum Number of Mid/Low/High Characteristic Squares]], for example.

@@ Line 400: / Line 400: @@
 ==== Interaction between Mesh Size and Weighted Ranges ====
-Mesh size determines how many intersection points the world will have. As an example, setting it to 2×2 means the world will be divided into 4 areas, 2 across and 2 tall, and there will be a total of 9 intersection points (3×3). The grid intersection points are in the middle of world tiles, and the minimum size for a grid area is a span of 9 world tiles in either direction, with adjacent areas sharing an overlapping world tile. On a pocket world, this means one grid tile will span 9×9 world tiles, whereas on a large world, one grid tile will span 129×129 world tiles. A pocket world will always use a 2×2 grid areas of 9×9 world tiles, since it has only 17×17 tiles total (even if the game UI allows setting those worlds to a 4×4 grid, which can happen when changing the world size; changing the world size doesn't adjust mesh size limits, but saving then reloading the parameters does). A world that is 17 tiles wide, but 257 tall, and set to a 32×32 mesh size, will have 3×33 intersection points.
+Mesh size determines how many intersection points the world will have. As an example, setting it to 2×2 means the world will be divided into 4 areas, 2 across and 2 tall, and there will be a total of 9 intersection points (3×3). The grid intersection points are in the middle of world tiles, and the minimum size for a grid area is a span of 9 world tiles in either direction, with adjacent areas sharing an overlapping world tile. On a pocket world, this means one grid tile will span 9×9 world tiles, whereas on a large world, one grid tile will span 129×129 world tiles. A pocket world will always use a 2×2 grid of 9×9 world tiles, since it has only 17×17 tiles total (even if the game UI allows setting those worlds to a 4×4 grid, which can happen when changing the world size; changing the world size doesn't adjust mesh size limits, but saving then reloading the parameters does). A world that is 17 tiles wide, but 257 tall, and set to a 32×32 mesh size, will have 3×33 intersection points.
-Setting mesh size to something other than Ignore, will apply random values at those intersections, with those random values being more likely to be in the higher weighted ranges. Setting to Ignore will cause the weighted range settings to be ignored for that terrain characteristic; instead setting the 4 corners of the world to completely random values and smoothing between those.
+Setting mesh size to something other than Ignore, will apply random values at those intersections, with those random values being more likely to be in the ranges with higher weights. Setting to Ignore will cause the weighted range settings to be ignored for that terrain characteristic; instead setting the 4 corners of the world to completely random values and smoothing between those.
-For example, if the Elevation Weighted Range parameters are set to <code>60:10:10:10:10</code> (starting with the 0-20 range, and these values do not have to add up to any particular number), and elevation min and max are left at the defaults of 1 and 400 respectively, then about 60% (on average) of the grid line intersection points will be set to an elevation in the range of 1-80 (0% to 20%), and the other ranges will be represented by around 10% of the intersection points each. The exact distribution is still left up to chance, though ''on average'' it will be close to this specification. This allows random number generation to be non-linear for the given terrain characteristic.
+For example, if the Elevation Weighted Range parameters are set to <code>60:10:10:10:10</code> (starting with the 0-20 range, and these values do not need to add up to any particular number), and elevation min and max are left at the defaults of 1 and 400 respectively, then about 60% (on average) of the grid line intersection points will be set to an elevation in the range of 1-80 (0% to 20%), and the other ranges will be represented by around 10% of the intersection points each. The exact distribution is still left up to chance, though ''on average'' it will be close to this specification. This allows random number generation to be non-linear for the given terrain characteristic.
 Setting the weight for a range to None only prevents intersection points from being set to a value in that range; terrain between intersection points can still be smoothed to values in ranges set to None that are between the intersection point values.

@@ Line 400: / Line 400: @@
 ==== Interaction between Mesh Size and Weighted Ranges ====
-Mesh size determines how many intersection points the world will have. As an example, setting it to 2×2 means the world will divided into 4 areas, 2 across and 2 tall, and there will be a total of 9 intersection points (3×3). The grid intersection points are in the middle of world tiles, and the minimum size for a grid area is a span of 9 world tiles in either direction, with adjacent areas sharing an overlapping world tile. On a pocket world, this means one grid tile will span 9×9 world tiles, whereas on a large world, one grid tile will span 129×129 world tiles. A pocket world will always use a 2×2 grid areas of 9×9 world tiles, since it has only 17×17 tiles total (even if the game UI allows setting those worlds to a 4×4 grid, which can happen when changing the world size; changing the world size doesn't adjust mesh size limits, but saving then reloading the parameters does). A world that is 17 tiles wide, but 257 tall, and set to a 32×32 mesh size, will have 3×33 intersection points.
+Mesh size determines how many intersection points the world will have. As an example, setting it to 2×2 means the world will be divided into 4 areas, 2 across and 2 tall, and there will be a total of 9 intersection points (3×3). The grid intersection points are in the middle of world tiles, and the minimum size for a grid area is a span of 9 world tiles in either direction, with adjacent areas sharing an overlapping world tile. On a pocket world, this means one grid tile will span 9×9 world tiles, whereas on a large world, one grid tile will span 129×129 world tiles. A pocket world will always use a 2×2 grid areas of 9×9 world tiles, since it has only 17×17 tiles total (even if the game UI allows setting those worlds to a 4×4 grid, which can happen when changing the world size; changing the world size doesn't adjust mesh size limits, but saving then reloading the parameters does). A world that is 17 tiles wide, but 257 tall, and set to a 32×32 mesh size, will have 3×33 intersection points.
 Setting mesh size to something other than Ignore, will apply random values at those intersections, with those random values being more likely to be in the higher weighted ranges. Setting to Ignore will cause the weighted range settings to be ignored for that terrain characteristic; instead setting the 4 corners of the world to completely random values and smoothing between those.

@@ Line 400: / Line 400: @@
 ==== Interaction between Mesh Size and Weighted Ranges ====
-Mesh size determines how many intersection points the world will have. As an example, setting it to 2×2 means the world will divided into 4 areas, 2 across and 2 tall, and there will be a total of 9 intersection points (3×3). The grid intersection points are in the middle of world tiles, and the minimum size for a grid area is a span of 9×9 world tiles, with adjacent areas sharing an overlapping world tile. On a pocket world, this means one grid tile will span 9×9 world tiles, whereas on a large world, one grid tile will span 129×129 world tiles. A pocket world will always use a 2×2 grid areas of 9×9 world tiles, since it has only 17×17 tiles total (even if the game UI allows setting those worlds to a 4×4 grid, which can happen when changing the world size; changing the world size doesn't adjust mesh size limits, but saving then reloading the parameters does).
+Mesh size determines how many intersection points the world will have. As an example, setting it to 2×2 means the world will divided into 4 areas, 2 across and 2 tall, and there will be a total of 9 intersection points (3×3). The grid intersection points are in the middle of world tiles, and the minimum size for a grid area is a span of 9 world tiles in either direction, with adjacent areas sharing an overlapping world tile. On a pocket world, this means one grid tile will span 9×9 world tiles, whereas on a large world, one grid tile will span 129×129 world tiles. A pocket world will always use a 2×2 grid areas of 9×9 world tiles, since it has only 17×17 tiles total (even if the game UI allows setting those worlds to a 4×4 grid, which can happen when changing the world size; changing the world size doesn't adjust mesh size limits, but saving then reloading the parameters does). A world that is 17 tiles wide, but 257 tall, and set to a 32×32 mesh size, will have 3×33 intersection points.
 Setting mesh size to something other than Ignore, will apply random values at those intersections, with those random values being more likely to be in the higher weighted ranges. Setting to Ignore will cause the weighted range settings to be ignored for that terrain characteristic; instead setting the 4 corners of the world to completely random values and smoothing between those.

@@ Line 388: / Line 388: @@
 |}
-=== Terrain Mesh Sizes and Weights ===
+=== Terrain Mesh Sizes and Range Weights ===
+[[File:World_map-large-32x32-elevation-mesh.png|thumb|300px|A large world generated with an Elevation Mesh Size of 32×32 and range weights set to 1:0:0:0:1 (i.e., only extreme high and low elevations). Note how the grid intersections are either set very high (mountains) or very low (oceans) and the space between them is smoothed out.]]
-These parameters make it possible to influence the number of squares in a particular range, without making conditions outside of that range impossible. For example, you can make it possible for many more low-elevation squares to exist without making it impossible for high elevations to form. Changing these parameters is often preferable to simply changing the min/max values.
+These parameters influence the relative proportions of terrain feature ranges, without making other ranges impossible. For example, to have many more low-elevation squares exist, without making it impossible for high elevations; this makes changing these parameters often preferable to simply changing the above min/max values. See the image on the right for an example.
 The basic steps of applying weighted ranges are as follows:
+# Divide the world into a grid of quantity <code>2<sup>''MeshSize'' - 1</sup></code> areas in both X and Y direction.
 # At each grid intersection, set the value according to the weighted ranges.
-# Smooth out the area between the intersection points.
+# Smooth out the areas between the intersection points.
 # Add noise according to the variance parameters.
-where ''MeshSize'' is the raw parameter value found in the world_gen.txt. See the image on the right for an example.
+==== Interaction between Mesh Size and Weighted Ranges ====
+Mesh size determines how many intersection points the world will have. As an example, setting it to 2×2 means the world will divided into 4 areas, 2 across and 2 tall, and there will be a total of 9 intersection points (3×3). The grid intersection points are in the middle of world tiles, and the minimum size for a grid area is a span of 9×9 world tiles, with adjacent areas sharing an overlapping world tile. On a pocket world, this means one grid tile will span 9×9 world tiles, whereas on a large world, one grid tile will span 129×129 world tiles. A pocket world will always use a 2×2 grid areas of 9×9 world tiles, since it has only 17×17 tiles total (even though the game UI allows setting those worlds to a 4×4 grid).
-==== Mesh Size/Weighted Ranges ====
+Setting mesh size to something other than Ignore, will apply random values at those intersections, with those random values being more likely to be in the higher weighted ranges. Setting to Ignore will cause the weighted range settings to be ignored for that terrain characteristic; instead setting the 4 corners of the world to completely random values and smoothing between those.
-Mesh size determines how many grid tiles there will be. Setting this to Ignore will cause the weighted range settings to be ignored for that terrain characteristic. As an example, setting it to 2×2 means the grid will be 2 times 2 tiles large and there will be 3×3 for a total of 9 intersection points. On a pocket world, this means one grid tile will be 8×8 world tiles large, whereas on a large world, one grid tile will be 128×128 world tiles. Note that the highest possible value for a given world size will always make the grid tiles 8×8 world tiles large.
+For example, if the Elevation Weighted Range parameters are set to <code>60:10:10:10:10</code> (starting with the 0-20 range, and these values do not have to add up to any particular number), and elevation min and max are left at the defaults of 1 and 400 respectively, then about 60% (on average) of the grid line intersection points will be set to an elevation in the range of 1-80 (0% to 20%), and the other ranges will be represented by around 10% of the intersection points each. The exact distribution is still left up to chance, though ''on average'' it will be close to this specification. This allows random number generation to be non-linear for the given terrain characteristic.
-If mesh size is set to something other than Ignore, these weights will be applied at the granularity of the selected mesh size for purposes of generating random values in each range. This allows random number generation to be non-linear for the given terrain characteristic.
+Weighted ranges do not make rejection checks, although they can be responsible for many rejections if you neglect to adjust or disable some of the [[#Minimum Number of Mid/Low/High Characteristic Squares|Minimum Number of Mid/Low/High Characteristic Squares]], for example.
-For example, if the Elevation Weighted Range parameters were set to (starting with the 0-20 range) 60:10:10:10:10 (these values do not have to add up to any particular number) and elevation min and max are set to 1 and 400 respectively then about 60% of the grid line intersection points (on average) will be set to an elevation in the range of 1-80 (0% to 20%), and the other ranges will be represented by around 10% of the intersection points each. The exact distribution is still left up to chance though ''on average'' it will be close to this specification.
+==== Interaction between these and Variances ====
+The end result can vary greatly depending on how the corresponding [[#X_and_Y_Variance|X and Y Variance]] parameters are set. First of all, if the variance is too high, the noise it adds can completely negate the effect of the weighted ranges. For instance, with a 2×2 mesh, the default variance parameters are high enough that usually the mesh grid can hardly be recognized. How strong the variance's effect is, is also dependent on the mesh size. Having a larger mesh size (i.e. smaller grid tiles) means the variance also has to be higher for a visible effect. For instance, with a variance of 400, the effects are clearly visible with a 2×2 mesh and barely visible at all with a 8×8 mesh. Note that this effect is directly dependent on the mesh size and not, as one might expect, on the actual size of the grid tiles. This means, that a large world with a 32×32 mesh will look essentially the same as a pocket world with a 2×2 mesh, only stretched to 256 times the size.
 Also see this [http://www.bay12forums.com/smf/index.php?topic=139916.0 forum post] for more details.
 ==== Configuration Tokens ====
 {| {{prettytable}}
 |- bgcolor="#dddddd"

@@ Line 102: / Line 102: @@
 Normally, you don't enter these seed values, the game comes up with values based on some other sort of pseudo-random information from things like the current date and time.
-When generating a world, ''Dwarf Fortress'' records the seeds it used in [[gamelog.txt]].
+When generating a world, ''Dwarf Fortress'' records the seeds it used in [[gamelog.txt]]; they can also be found with <code>gui/gm-editor world.worldgen.worldgen_parms</code> in [[DFHack]].
 == Advanced parameters ==

@@ Line 229: / Line 229: @@
 === Site cap after civ creation ===
-Total number of [[site]]s that can be directly created by all civilizations combined like [[hillocks]], [[hamlet]]s, [[dark pits]], [[forest retreat]]s, etc. Does not prevent the placement of initial civilization sites, though they will then be counted for the limit. Does not affect creature sites like [[cave]]s or [[lair]]s, group sites like [[castle]]s, [[monastery|monasteries]], [[tower]]s, [[fort]]s, or [[camp]]s, or unpopulated sites like [[tomb]]s. After this limit is reached, no civilization will be able to place new sites. See the [[Entity_token#Placement|placement]] entity tokens for other ways that civilization site placement can be limited.
+Total number of [[site]]s that can be directly created by all civilizations combined like [[hillocks]], [[hamlet]]s, [[dark pits]], [[forest retreat]]s, etc. Does not prevent the placement of initial civilization sites, though they will then be counted for the limit. Does not affect creature sites like [[cave]]s or [[lair]]s, group sites like [[castle]]s, [[monastery|monasteries]], [[tower_(necromancy)|tower]]s, [[fort]]s, or [[camp]]s, or unpopulated sites like [[tomb]]s. After this limit is reached, no civilization will be able to place new sites. See the [[Entity_token#Placement|placement]] entity tokens for other ways that civilization site placement can be limited.
 Increasing this will slow generation down and reduce the available places for player sites. Since the {{token|MAX_SITE_POP_NUMBER|entity}} entity token limits the historical figure population per site, this site cap can also limit the total historical figure population of all civilizations combined, and some expand faster than others getting more sites before the limit is reached.

@@ Line 648: / Line 648: @@
 === Number of Demon Types ===
-[[Demon]]s are similar to [[titan]]s and [[forgotten beast]]s, in that they are procedurally generated, but most are not unique. Thus, many different types of demons can exist in the world, but there will also be many individuals of most types. Thanks to [[Underworld spire|certain fun things]], fewer demon types also means fewer goblin civilizations[http://www.bay12forums.com/smf/index.php?PHPSESSID=7348f68f41a9659443c05b2acf534e6c&topic=112465.15]. You need at least 2 demon types, or else goblin civilizations won't exist initially, though if dwarves breach the underworld during world generation, at least one will be generated then.<!-- May be 1 per underworld region? -->
+[[Demon]]s are similar to [[titan]]s and [[forgotten beast]]s, in that they are procedurally generated, but most are not unique. Thus, many different types of demons can exist in the world, but there will also be many individuals of most types. Thanks to [[Underworld spire|certain fun things]], fewer demon types also means fewer goblin civilizations.{{cite forum|112465/7392706}} You need at least 2 demon types, or else goblin civilizations won't exist initially, though if dwarves breach the underworld during world generation, at least one will be generated then.<!-- May be 1 per underworld region? -->
 {| {{prettytable}}