Build a system to compose terrain transitions on the fly

[CelticMinstrel]

Currently, if you want a transition from grass or hills or mountains to a new terrain, it takes up 12 terrain slots per pair of terrains that require a transition. If we could split the existing transitions in half in such a way that one half can be overlaid upon a new base terrain, that would make it a lot easier add new transitions.

It would eliminate a lot of terrains from the base set in Blades of Exile Base – for example, only the encircled ones in the following image would remain as terrains. The graphics for the transitions would still be present, of course, but they'd take up a lot less space than they do now – there are duplicates of these transitions on other sheets for mountain-to-snow and other combinations. It would also make it easier to build three-way terrain transitions.