Difference between revisions of "Advanced world generation"

{{Quality|Exceptional|18:16, 23 August 2014 (UTC)}}

:''This article contains information on advanced world generation. For information on basic world generation, see [[World generation]].''

:''See [[World token]] to more easily find information by the names used in the world_gen.txt file.''

:''See [[World rejection]] for information on solving problems related to worlds always being rejected.''

:''See [[Worldgen examples]] for example worlds.''

When you want more control of what your world looks like, it's time for '''advanced world generation'''. A detailed reference with advice is provided below. This article assumes that you are already familiar with [[World generation|'''basic''' world generation]]. If you are not then please read about that first.

 

Once you select {{DFtext|Design New World With Advanced Parameters}} from the main menu, a screen that looks something like this will appear:

 

 

This screen is relatively intuitive but some parts could use some explanation.

The list of already defined parameter sets is in the upper right corner. You can select the current set that you want to work with using the up and down directional keys.

 

Hitting {{K|a}} will add a new set to the end of the list. You can also {{K|c}}opy an existing set to a new one allowing you to base a new set on an existing one. Using {{K|t}} you can change the name of the parameter set but note that this will not affect the name of the world that is generated.

Parameter sets are stored in the <tt>data/init/world_gen.txt</tt> file in the main DF directory. The {{K|F1}} and {{K|F6}} keys will load and save '''all''' of the parameter sets to this file. You will need to save the world gen parameters to this file before you hit {{K|Enter}} to generate the world.

 

The tokens used in <tt>world_gen.txt</tt> are at the bottom of each parameter description. Here's the one for title.

As previously mentioned, the title of the parameter set doesn't affect the name of the world. You can force a particular name for your world using {{K|n}} or set it back to the default random setting using {{K|N}}.

The size of the map to be generated can be selected with {{K|u}} {{K|i}} {{K|o}} {{K|p}}. Larger maps take longer to generate and may limit [[Frames per second|FPS]] in game.

Changing the dimensions of the world will reset the parameters because many of them have different defaults depending on the surface area available.

 

Creating larger worlds does not necessarily mean longer world generation time. The essential factor for the duration is the history. If you restrict the number of historical events you can fasten the process very much.

| Valid values are 17,33,65,129, and 257. Others may not work.

The world generation process uses a PRNG (Pseudo Random Number Generator) algorithm. A PRNG will produce a sequence of numbers that "looks" random even though the actual sequence of numbers will always be the same if the PRNG is started with the same seed value. Basically this means that if you run world generation with a certain seed value on your computer, and someone else runs world generation with the same seed value on their computer, the same sequence of random numbers will be generated on both computers. The practical impact of this is that someone else can generate exactly the same world that you generated by entering the same seed value that you used.

In older versions, the same seed value(s) produced identical world on every computer at any time (if other parameters were identical, too). In the current version, the seed values for the world itself and the names seem to produce the same result, but you will get changes in events cumulating to an different world-history at all. It seems like the history is random somhow and not completely connected to the seed. Keep this in mind if you wand to regenerate a particular world.

A specific seed value can be entered with {{K|s}}. This will change '''all''' of the seed values to the value you enter. If you need to enter different seed values for each type of seed, use {{K|e}}.

In order to find out what seed values were used for the last world you generated you can look at this screen. If you want to be able to tell someone else how to generate exactly the same world that you just generated, they will need all of the seed value listed under Last Param Set.

 

The following are tokens which appear to be involved in the implementation of the seed and are not safe to change:

Many other world parameters such as end year and embark points can however be changed without it having any effect on the geography of the world generated from the seed values.

Normally you don't enter these seed values and the world generation process comes up with seed values based on some sort of "true" random information from things like random values in uninitialized memory, the current date/time, etc. If you have entered a seed value you can revert to all seeds being random using {{K|S}}.

Unless you're using an already defined parameter set you will probably want to {{K|e}}dit the parameters. Select the set you want to edit using the up/down directional keys and press {{K|e}}. Information about each parameter is documented below.

 

Once you are happy with the parameters you have set, hit {{K|Esc}} to get back to this screen, hit {{K|F6}} to save the values you just edited, and hit {{K|Enter}} to start. The rest of the process is the same as basic [[World generation]].

Parameter sets are stored in ''world_gen.txt'' in the ''\data\init'' folder, using [[world token]]. You can copy and paste other player's sets of parameters into your ''world_gen.txt'' to use their parameter sets, and some are provided at [[Main:Pregenerated worlds|Pregenerated worlds]]. Another place to find parameter sets is the [http://www.bay12forums.com/smf/index.php?topic=101280.0 Worldgen cookbook] thread on the official forums.

To access advanced parameters, press {{key|e}} when at the screen for creating new worlds with parameters screen. This will bring you to an editable list of various guidelines the world-gen process will use when creating your new world.

The parameters are described below in the order that they appear in the list in the UI, not necessarily the other they appear in the configuration file. See [[world token]] for an index that will help you look things up by token name.

Terrain Parameters, as described below, these 5 variables define the basic background world, how hot or cold it is, how much rainfall, how high the mountains are. The world automatically goes through the temperature range along the Y axis although sometimes it will be hotter in the north, other times in the south. Minima and maxima and X,Y variance can drastically alter the world.  

Weighted Meshes, these are a way to fine tune the amount of the 5 basic variables on the map. It can be used to set the specific distribution of different elevations or rainfall areas for example.  

Rejection Parameters, Dwarf Fortress has a belt and braces approach to world generation. The above controls allow you to shape the world then the rejection parameters throw it out if it isn't right! There are a number of rejection parameters for the number and degree of the 5 basic variables, for biome types etc. If the world does not meet the requirements of any one rejection parameter the world is rejected an re-randomised. Also see [http://dwarffortresswiki.org/index.php/DF2012:World_rejection World Rejection]

The are also the feature placing options such as rivers, mountain peaks, volcanoes and oceans. These can cause rejections if the terrain parameters don't allow enough suitable locations for the features to be placed.  

If you are experimenting with world design, one method would be to disable the rejection parameters and use the first two control types. Otherwise any significant change will likely result in endless rejections.

Here you can enter specific seed values for different parts of the world generation process. Different sequences of pseudorandom numbers are used for different parts, so you can use this to reproduce only the particular part of world generation from some previously generated world if you want.

This controls the number of points that you have for skills and equipment when you embark in fortress mode. Turning this value up will allow games started in this world to start with more skilled dwarves with better equipment. Normally you can do just fine by leaving this value set to default, but you might want to up it for experimental/testing purposes or to help dwarves survive in a particularly evil world.

| <tt><nowiki>[EMBARK_POINTS:1274]</nowiki></tt>

This is how many years of history are generated for the world. This is basically the same as the History parameter in basic world gen, except that you can enter an exact value for number of years. See [[World_generation#History|History]] for more info.

This determines the maximum possible population of civilization member historical figures alive at a given time during worldgen. Not all members of a civilization are historical figures. This tag does not directly influence the total population of civilized beings as it once did when populations were all historical figures, so the description is a bit confusing. You can enter -1 to make the historical population unlimited.

This controls the maximum number of towns and similar sites on the entire map. Raising the number will allow for more towns, etc. though the number of sites will ultimately still be limited by things like space, terrain, and population cap.  

Note that '''this parameter controls only "civilization" sites''' like towns.  Other sites such as lairs will be added on to this maximum.  After civilizations reach this cap, they will not spread out anymore to place new cities.

 

Increasing this too high can slow worldgen down by a lot, beware.

The world starts out with a certain number of powerful megabeast and titan entities in existence. If a percentage of the megabeast and titan population dies out during history generation, then history generation will stop early. For example, if the elimination value is 80%, and the generated history starts with 200 entities and 160 of those 200 entities are eliminated by historical events before the End Year is reached, history generation will stop early.

The percentage of dead megabeasts and titans for stoppage will not be checked until this year is reached in history generation. This can be used to ensure that a world reaches a certain year even if all of the megabeasts in the world are slain earlier.

Whether or not the game ignores unimportant figures in history generation. The culling is many CPU-intensive steps in history generation but it saves memory and will speed up loading/saving games a bit. This does mean that the "unimportant" figures will not appear in Legends mode or in things like dwarf engravings, but they might not appear in engravings anyway.

Unimportant figures are people or creatures who suffer early deaths, never having offspring or killing anything named during history generation. For example, residents of goblin towers may get murdered by demons at a young age. After culling unimportant figures, Legends mode would say something like the demon has killed "a creature at Eviltower in the year 102."

Setting this to Yes will allow access to all information about the history of the world in Legends mode. If set to No, then you will have to discover historical information in adventure mode or by instructing dwarves to make engravings.{{Verify}}

These are the absolute minimum and maximum values that can ever be generated for a particular map square characteristic. Changing these can cause the occurrence of certain [[Biome|biomes]] to become impossible, so modify these with care. Because of this problem, you may want to use [[#Weighted Ranges|Weighted Ranges]] instead.

 

By ''subtly'' tweaking the min and max values, vastly different maps can be made.

 

 

 

 

For "patchwork" worlds to avoid being rejected, [[#Maximum_Number_of_Subregions|Maximum Number of Subregions]] will probably need to be increased from the default.

Raising the variance will result in a more bumpy uneven landscape.

* River start locations need a minimum elevation of 300. Therefore, a world with a maximum elevation of 299 everywhere prevents river generation, but rivers can still occur if maximum elevation is set to 300.

*Mountain peaks can only form in squares with an elevation of 400.

Controls the amount of rainfall in each map square/area. Setting the minimum too high or the maximum too low can make the formation of certain biomes impossible. Rainfall causes it to [[Rain]] more in a given area, which can have various effects.

Also makes more rivers appear on the world map.

Note that if [[#Do Orographic Precipitation and Rain Shadows|orographic precipitation and rain shadows]] is on then mountains will cause additional variance in rainfall, so (for example) rainfall below the specified minimum can occur in the shadow of a mountain. If you want the minimum and maximum for this parameter to be absolutely respected you must turn off the orographic precipitation option.

[[Temperature]] is always influenced by elevation and, if [[Advanced_world_generation#Poles|Poles]] are enabled, latitude. So, the value from the temperature rolling process is ''not the absolute temperature value the region will get, but rather local variation.'' The "base" temperature for an area is derived from its latitude and elevation, and then the random value determined by these parameters are applied to it to make it vary a bit. The default values for the local variation are fairly small compared to the base temperature, which appears to be hard coded.

Lower drainage values have been reported to contribute to the formation of thicker soil layers though it is currently unknown exactly how other factors (such as elevation or perhaps rain) impact soil formation.

Volcanism controls the occurrence of Igneous [[Layer|Layers]], and the formation of volcanoes. For a volcano to form, a square must have a volcanism value of 100 so reducing the maximum from 100 will make volcanoes impossible. Raising the minimum will increase the rarity of non-igneous layers.

Setting minimum to high value is not a good way to produce multiple volcanoes as you are likely to get a "Volcanism not evenly distributed" rejection. Instead use the Minimum Number of Volcanoes parameter and possibly adjust the weighted ranges for volcanism as described below.

These parameters control the level of [[Surroundings#Savage|savagery]] on the map. Raising the minimum savagery too high may make it impossible for certain races to exist, and similarly lowering the maximum too far can make it impossible for certain creatures to exist. The largest chance of having unusable maps comes from too high of a savagery value.

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.

# Set the intersection points of the grid lines to a random value according to the weighted ranges.

Where ''MeshSize'' is the raw parameter value found in the world_gen.txt. See the image on the right for an example.

[[File:World_map-large-32x32-elevation-mesh.png|thumb|300px|A large world generated with an Elevation Mesh Size of 32x32 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 or very low and the space between them is smoothed out.]]

==== Mesh Size ====

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 2x2 means the grid will be 2 times 2 tiles large and there will be 3 times 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.

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 large the noise it adds can completely negate the effect of the weighted ranges. For instance, with a 2x2 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 2x2 mesh and barely visible at all with a 8x8 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 2x2 mesh will look essentially the same as a pocket world with a 2x2 mesh, only stretched to 256 times the size.

With this you can influence how polar regions are added. The poles can be on the north or south edge and the equator will be on the opposite edge or in the middle if there are two poles.

This will cause the world to be rejected if fewer than this many peaks (based on elevation) are present on the map. Elevations of 400 must be possible for mountain peaks to occur. If set to zero then worlds will not be rejected based on number of peaks.

You may need to adjust elevation parameters, such as the highest weighted range, in order to get the desired number of elevation 400 squares needed for larger numbers of peaks. Like volcanoes, mountain peaks can make embark zones more interesting but other than that they don't appear to "do" anything special. Reportedly they do increase the highest Z-level above ground in all embark zones in the same region even if the selected embark zone does not include the peak.

Note that the ability for this many edge oceans to exist will be limited by elevation. Therefore to actually create large oceans you will probably need to change things like the Elevation Mesh Size and Weighted Ranges to increase the number and distribution of very low elevation squares on the map.

Given appropriate weight, range, and variance values for things like elevation, a setting of:

*1 results in a world that seems like a chunk of coastline. One edge of the map will be completely underwater and there will be ocean taking up much of the map on that side.  Think the east or west coast of the United States, the north coast of Canada, or southern Europe.  If your edge ocean happens to pick your world's frozen side most of it will be glacier.

*2 results in another coastline along with the first one.  The map could end up looking something like Panama if the oceans pick opposite sides of the map.

Edge oceans will take up part of the other edges too.  For example a full edge ocean on the east side will have part of the north and south sides underwater, but that does ''not'' add to the ''partial'' edge oceans count.

Worlds with less than this number of volcanoes will be rejected. Note that this will not just create this many volcanoes at random; there must be at least this many squares with a Volcanism of 100. Therefore adjusting Weighted Range for 80-100 to some higher value is recommended if you want to facilitate a large number of volcanoes. In addition, Maximum Volcanism must be set to 100 or squares with volcanism of 100 will be impossible making volcanoes impossible.

Controls the frequency at which minerals occur. Setting this value lower will increase the amount of ore present on a map, the number of different types of ore, and the number/types of gems. The default value will result in a maximum of 2-4 metal ores per map (assuming you choose a good embark location) which may be limiting until the economy is fully implemented and desired metals can be traded for.

This is for the same 8x8 embark region in a world which is otherwise the same except for the mineral scarcity parameter (although most of the detailed information comes from experiments with previous versions).

=== Max Megabeasts Caves ===

This is the number of megabeasts placed at the beginning of history. Megabeasts are hydras, bronze colossuses, rocs and dragons which are all placed in equal proportions [http://www.bay12forums.com/smf/index.php?topic=112465.msg3415177#msg3415177 ^data].  

This is the number of semi-megabeasts placed at the beginning of history. Semi-megabeasts are giants, ettins, minotaurs, and cyclopes, which are placed in equal proportions [http://www.bay12forums.com/smf/index.php?topic=112465.msg3415188#msg3415188 ^data].

| Semimegabeasts do not count towards BEAST_END_YEAR calculation.

This controls the number of titans that exist at the beginning of history[http://www.bay12forums.com/smf/index.php?topic=112465.msg3415203#msg3415203 ^data]. The number of forgotten beasts is unaffected by this parameter [http://www.bay12forums.com/smf/index.php?topic=112465.msg3415155#msg3415155 ^data].

Megabeasts will begin to attack your fort once at least this many dwarves inhabit it, regardless of whether any other attack criteria have been met. This number defaults to 80 which isn't usually too difficult to deal with.

Megabeasts will begin to attack your fort once you have exported at least this many [[Currency|dwarfbucks]] worth of merchandise, regardless of whether or not any other criteria have been met. This parameter defaults to None (disabled).

Megabeasts will begin to attack your fort once the fort's total wealth has reached this many [[Currency|dwarfbucks]] in value. This happens regardless of whether any of the other criteria, such as population, have been met; therefore, even with 1 dwarf, a fort could be attacked if the fort were worth at least this value.

[[Demon|Demons]] are similar to titans and forgotten beasts in that they are procedurally generated, but unlike titans they are not unique. Thus many different types of demons will exist in the world but there will be many members of each type. Setting this to zero means no demons will exist, limiting the amount of fun you can have.

The number of different [[Night troll|night trolls]] that will exist in the world. These are also procedurally generated. Setting this to zero means that the world will have no night trolls.

 

The number of different [[Bogeyman|bogeyman]] forms that will exist in the world. Bogeyman are procedurally generated, though their forms do not vary by much. Setting this to zero, means that the world will have no bogeyman. Additionally setting this to zero will not allow custom bogeymen to appear in the world.

The number of different [[Vampire|vampires]] that will exist in the world. Although they too are generated at the start of a new world, they generally no different from one another, with the biggest difference being what stat bonuses their vampirism gives {{verify}}. Setting this to zero means no vampires will exist.

=== Number of Werebeast Curse Types ===

The number of different [[Werebeast|werebeasts]] that can exist in the world. It is common for werebeasts, unlike vampires, to assume many different forms and variations, the most well known of these amount as different species of animal beasts. From lizards, to wolves, to maybe even bears. Setting this to zero means no werebeasts will exist.

The number of secrets that exist in the world. Currently, all secrets are secrets of life and death, and the ones holding these secrets are necromancers. Setting this to zero means that no [[necromancer]]s will appear.

| <tt><nowiki>[SECRET_NUMBER:44]</nowiki></tt>

The number of different [[Mummy|disturbed dead]] {{verify}} that can exist in the world. Setting this to zero, while being as pointless as is, (since you're never forced to enter a tomb anyway), will most likely prevent any toilet roll spooks from appearing, but it may or may not also prevent the existence of the pyramids which house them too.

=== Number of Evil Cloud Types ===

 

The lesser of a relatively large group of evils... evil rain. This number states how many different types of green-ooze drenchers, disconcerting blood-showers, and sickly yellow slime-baths can occur in your world. Compared to evil clouds though, this one hardly is worth stressing out about, usually.... Setting this to zero means the only semi-solid to fully liquid liquids to fall from the sky will be pure H2O.  

 

This turns the generation of [[Divine_metal|divine metals]] on or off. It does not influence the creation of vaults.

===