Editing v0.31:Advanced world generation

{{quality|Exceptional|18:29, 1 December 2010 (UTC)}}{{av}} 
= Advanced Parameters =

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.

Parameter sets are stored in ''world_gen.txt'' in the ''\data\init'' folder, using [[world tokens]]. 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 [[Pregenerated worlds]]. Another place to find parameter sets is the [http://www.bay12games.com/forum/index.php?topic=20638.0 Worldgen cookbook] thread on the official forums.

== Caverns Parameters ==

=== Cavern Layer Number ===

This parameter determines how many cavern systems will be generated, not including the Magma layer or the Bottom layer.  Defaults to three.

If this is 0 then you will not have Caverns on your map. Note that disabling caverns will make it impossible to grow any underground plants because none will exist for your civilization to cultivate.


Example:<blockquote>
[CAVERN_LAYER_COUNT:3]
</blockquote>

=== Layer Openness min\max ===

Dictates the size of cavern passages. When Passage Density (see below) is set to minimum (0), caverns will be open expanses. Raising the maximum will increase the size of the caverns.

Example:<blockquote>
[CAVERN_LAYER_OPENNESS_MIN:0]<br />
[CAVERN_LAYER_OPENNESS_MAX:100]
</blockquote>

=== Layer Passage Density min\max ===

This determines how many passages form the cavern. If openness (see above) is set to minimum and density increased then you will get a maze like network of small criss-crossing passages. Raising the values further increases the number of the maze-like passages.

Example:<blockquote>
[CAVERN_LAYER_PASSAGE_DENSITY_MIN:0]<br />
[CAVERN_LAYER_PASSAGE_DENSITY_MAX:100]
</blockquote>

==== Layer Openness and Layer Passage Density ====

Open caverns and dense passageways are not mutually exclusive. When both are raised, bizarre results can occur, such as layers showing a combination of open caverns, a cluster of network passages, and natural walls sprinkling the inside of an otherwise open cavern. [http://www.bay12forums.com/smf/index.php?topic=76355.msg1936859#msg1936859 Reference]

If you want the largest open spaces possible, then decrease the density and increase the openness. If you want a labyrinth of passageways, lower the openness and raise the passage density.

Another interesting note about the cavern layers is that the seed and number of demon types effect the layout of the caverns.

=== Layer Water min\max ===

Determines how many caverns will have water at the bottom.  Note that, even at 100, there will be some amount of ground in caverns, but each cavern 'bubble' will contain some amount of water.

At 0, there will be no water in your caverns.  This may impact future underground plant growth, although maps will still start with underground flora.

Example:<blockquote>[CAVERN_LAYER_WATER_MIN:0]<br />
[CAVERN_LAYER_WATER_MAX:100]
</blockquote>

=== Magma Layer ===

Magma sea 4-5 layers at the bottom of map.

Value 1 forces magma layer, value 0 appears to prevent it.
<br />Appears not have impact on volcanoes, nor vulcanism, so even if 0 there will still be emark locations with magma.
<br />If a volcano exists, it appears to always tap the magma sea, but the magma sea will not be revealed by revealing the volcano.
<br />(Unconfirmed whether magma layer still can occur if HFS exists in a specific embark tile, e.g. Temple).


Example:<blockquote>[HAVE_BOTTOM_LAYER_1:1]
</blockquote>

=== Bottom Layer ===

Cavern below magma sea. 
If "yes" the "HFS" layer is always present.
Defaults to "yes".


If turned on, will force the magma layer above it.
<br />(Unknown whether this has any impact on occurrence of HFS temple)


Example:<blockquote>[HAVE_BOTTOM_LAYER_2:1]
</blockquote>

=== Z Levels ===
'''[Previous table clear as mud; this table murky pool.]'''

Following table based on having 3 cavern layers.  The Levels Above Layer settings control how many Z-Levels are above each layer.  A layer may itself consist of multiple Z-Levels (and almost always does).


{|style="margin:1em 1em 1em 0;background:#F9F9F9;border:1px #AAA solid;border-collapse:collapse;" class="wikitable"
|-style="background:#F2F2F2;text-align:center;"
!style="border:1px #AAA solid;padding:0.2em;" width="120"|Setting Name
!style="border:1px #AAA solid;padding:0.2em;" width="200"|file tag
!style="border:1px #AAA solid;padding:0.2em;"| Description
|-
|style="border:1px #AAA solid;padding:0.2em;"| Above Ground
|style="border:1px #AAA solid;padding:0.2em;"| LEVELS_ABOVE_GROUND
|style="border:1px #AAA solid;padding:0.2em;"| The number of Z-Levels of air above the highest surface level.<br />Has no impact on how many Z-levels deep the surface layer is.
|-
|style="border:1px #AAA solid;padding:0.2em;"| Above layer 1
|style="border:1px #AAA solid;padding:0.2em;"| LEVELS_ABOVE_LAYER_1
|style="border:1px #AAA solid;padding:0.2em;"| Z-Levels of stone above the first cavern layer.  Making this higher will guarantee ''at least'' this many levels to build your fortress, but will have no impact on how many z-levels thick the surface layer is.  Also, the top of a cavern may be higher than the rest of a cavern, so in practice there will be more levels than this.
|-
|style="border:1px #AAA solid;padding:0.2em;"| Above Layer 2
|style="border:1px #AAA solid;padding:0.2em;"| LEVELS_ABOVE_LAYER_2
|style="border:1px #AAA solid;padding:0.2em;"| Z-levels of earth between very top of second cavern and very bottom of first cavern.
|-
|style="border:1px #AAA solid;padding:0.2em;"| Above Layer 3
|style="border:1px #AAA solid;padding:0.2em;"| LEVELS_ABOVE_LAYER_3
|style="border:1px #AAA solid;padding:0.2em;"| Z-levels of earth between very top of third cavern and very bottom of second cavern.
|-
|style="border:1px #AAA solid;padding:0.2em;"| Above Layer 4
|style="border:1px #AAA solid;padding:0.2em;"| LEVELS_ABOVE_LAYER_4
|style="border:1px #AAA solid;padding:0.2em;"| Z-Levels of earth between very highest magma and very bottom of third cavern.<br />Spoiler Hidden: <span style='color:#eee;'>Making this high will give a large area for HFS veins, so that it never touches caverns, giving more to mine IF it was impacting the cavern previously.</span>
|-
|style="border:1px #AAA solid;padding:0.2em;"| Above Layer 5
|style="border:1px #AAA solid;padding:0.2em;"| LEVELS_ABOVE_LAYER_5
|style="border:1px #AAA solid;padding:0.2em;"| Uncertain.  May control the number of levels of "Semi Molten Rock" between HFS and Magma, may control number of levels of magma, may impact both.<br />In experimentation, the overall depth of all magma sea and semi-molten rock levels appears to increase, but not consistent enough to say for certain.<br />Only valid if Magma Layer present.<br />Spoiler Hidden:<span style='color:#eee;'>Often the HFS vein will only extend as high as the highest magma, making this the only guaranteed way to increase amount of HFS to mine, but unfortunately also creating enormous useless semi-molten z-levels</span>
|-
|style="border:1px #AAA solid;padding:0.2em;"| At Bottom
|style="border:1px #AAA solid;padding:0.2em;"| LEVELS_AT_BOTTOM
|style="border:1px #AAA solid;padding:0.2em;"| Appears to be number of levels of HFS chamber.<br />Only valid if Bottom Layer present.<br />Often has no impact.<br />Values larger than default results in strange things.
|-
|}


Some implications:
* The number of surface layers (e.g. soil), at this time, can not be controlled.  For example, on a map with 1 layer of Peat, then a layer of Silt, then a layer of Obsidian, there is no control to let you increase either one to be, say, 20 z-levels. (though you may get lucky with the Obsidian).
* There can be multiple stone layers between the cavern and the surface.  So increasing Levels Above Layer 1 may give you more Conglomerate, or more Granite, and you have no control over which stone layer spans those Z-Levels.
* The layers shown on embark span across the cavern layers in an unknown and inconsistent way.  Sometimes those 10 different layers of stone are evenly distributed over your 400 z-level deep map, sometimes the first 9 get 1 z-level each and the last gets the other 391 levels.  No way to control found yet.
* The HFS temple, if present, will always extend into the rock layers, and appears to always make contact with the bottom cave.  Large values for levels above layer 5 and layer 4 can result in enormous temples, but the number of levels at the top (the part with undead) appears to be unaffected.
* Unconfirmed whether number of levels between caverns has any impact on cavern height.  There will be connecting ramps and/or shafts between cavern layers no matter how many levels are between them.
* '''Very Important''': These values appear to apply across a whole 16x16 Region, not just embark areas.  That means that if a 16x16 region is completely flat, but has one tall mountain in one far corner, even if you set Levels Above Ground low (e.g. 2 z-levels) you still have all the empty air of the highest mountain in every embark tile (e.g. 200 z-levels).  Also can happen to the semi-molten layer, and can lead to unexpected behavior.
* Very large values can cause strange things to happen.  Even more true for small values.

== Volcanoes ==
=== Minimum Volcanism/Maximum Volcanism ===
Setting minimum to high value is not a good way to produce multiple volcanoes ("Volcanism not evenly distributed" rejection).

=== Minimum Volcano Number ===
You want to use this (you may wait for perfect world - 500 rejects for 100 volcanoes minimum is typical).