Custom world generation/structure


 * The root tag
 * : The ID of structure feature type.
 * : The biome tag that this structure is allowed to generate in.
 * : The step where the structure generates.
 * : (Optional, defaults to ) The type of terrain adaptation used for the structure .   for no adaptation,   is used by pillager outposts and villages,    is used by ancient cities, and   is used by strongholds.
 * : (Optional, but can be empty) Overrides the mobs that can spawn in this structure. Used for things like blaze and wither skeleton spawning in nether fortresses, and can also be used to block mobs from spawning like in ancient cities.
 * : (Optional, but can be empty) The config of this configured structure feature. The avialable configurations depends on . Types that are not listed below have no configuration.
 * If  is   :
 * The structure pool the structure starts from. Can be an ID of structure pool, or a structure pool object.
 * The depth of jigsaw structures to generate. Value between 0 and 7 (inclusive).
 * If  is unset, the structure will start at the value provided. Otherwise, the value acts as an offset from the heightmap.
 * (optional) The name of the jigsaw block the structure start attaches to.
 * (optional) The heightmap the start height should project to. Can be,  ,  ,  ,  , or.
 * The maximum 3D Chebyshev distance from the jigsaw pieces to the structure start. Value between 1 and 128 (inclusive) when is "none", otherwise from 1 to 116 (inclusive).
 * Only used for villages.
 * If  is  :
 * Either  or  .   for mineshaft made of oak, while   for mineshaft made of dark oak.
 * If  is  :
 * The y-value that the structure will start.
 * If  is  :
 * Either  or  . Determines which variant this structure uses.
 * : The probability of this structure using the large variant buildings. Value between 0.0 and 1.0 (inclusive).
 * : The probability of a cluster of ocean ruins generating, instead of just one. Value between 0.0 and 1.0 (inclusive).
 * If  is  :
 * A list of ruined portal setups to randomly choose one from it.
 * The weight this ruined portal setup will be chosen.
 * Either,  ,  ,  ,  ,  . Determines how the ruined portal will be placed.
 * The probability that the ruined portal will generate an air pocket around it. Value between 0.0 and 1.0 (inclusive).
 * Determines how mossy the ruined portal is, as an argument for  processor. Value between 0.0 and 1.0 (inclusive).
 * Determines whether or not jungle leaves generate.
 * Determines whether or not vines generate on the ruined portal.
 * Determines whether or not lava and magma can be replaced with netherrack.
 * Determines whether or not stone bricks in the ruined portal will be replaced with their blackstone equivalents.
 * If  is  :
 * (optional, defaults to false) Whether or not the shipwreck is beached.
 * If  is  :
 * (optional, defaults to false) Whether or not the shipwreck is beached.