Techtree - M2TW
Techtree slots are the mechanism in M2TW where buildings such as barracks and churches appear within the 3d models of settlements that have built those buildings.
Editing techtrees
The picture at the top right shows the techtree section of the .world file viewed in a hex editor.
Link to EDB
Useage
As well as the obvious use of allowing a barracks to appear as built within a settlement, a techtree can be used to load more-or-less anything! For instance in certain TATW mods a techtree is used to load a dummy settlement outside the main actual settlement, to represent a closely adjacent settlement without having to import all the models manually. To achieve this (as the dummy settlement is obviously not built via EDB) the techtree slot is set up with a unique category name and size and a .worldpkgdesc created to match that category and size but with "slot_filler" as the 'type'.