Transformers are small behaviors for a structure for when it spawns, such as hiding or transforming helper blocks (e.g. Generic Solids and Space blocks), run advanced randomization machinery or small commands to transform the structure into what it is supposed to look like for the player encountering it.
To understand this guide, it is recommended to read Guide: Building a Structure first.
Randomization Transformers[]
These transformers are intended to randomize the structure upon generation, ensuring that it looks different in every world and at every sight.
Natural Air[]
These transformers generate air bubbles around specific blocks (by default: Generic Air blocks) to make it integratable into caves or mountain sides.
Natural Floor[]
These transformers generate natural-looking floors for structures, defined by the biome type (e.g. sand for deserts). Placing Natural Floor blocks in the structure integrates it well into its surroundings due to this transformer!
Negative Space[]
This transformer deletes certain blocks from the structure, as if they were never part of it. Since structures are always formed as cuboids, this helps integrate it into the terrain. Using this transformer by placing Negative Space is essential to making a structure look natural. You can find a good example of its use in the "MeteorSite" structure.
Ruins[]
This transformer "ruinifies" the structure, making its blocks crumble, fall and deteriorate. This works well for structures that are build to look like they are abandoned, though yet intact, and it handles the ruinification of it falling apart over the years. As an example, the structure "SmallFortRuins" uses this transformer.
Replace[]
This transformer replaces blocks randomly in the structure, randomizing certain properties of it.
Village[]
This transformer replaces specific blocks according to a village's rules - so, it only applies to structure with a Village generation method.
Pillar[]
This transformer places a pillar of blocks under specific blocks (it is recommended to use Solids for this purpose, as an alternative way to integrate it into the terrain. This is a behavior that is exhibited in nether fortresses, which generate bridges standing on pillars.
Ensure Transformers[]
These transformers are intended to cancel a structure generation if certain conditions are not met. A structure might, for example, require a watery surface to generate on.
Transformer Groups (Multi Transformers)[]
These transformers are intended to provide grouping and presets for structures. If you have one or many transformers you are using the same way in multiple structures, it is recommended to group them, export them as preset and simply use the preset in every relevant structure.
World Script Transformers[]
The world script transformer is a very versatile transformer capable of running world scripts, similar to the Spawn Script block. In contrast to simply placing a spawn script block, however, world scripts added here are capable of running the same script on many blocks repeatedly after one another, which avoids copying the same script block many times to make it work.