Snapping Actors is a custom built C++ Actor class that allow for placement by snapping things into place based on pre-determined Snapping Pivots and Snapping Target Points (in addition to placing by hand or using grid-snap)
The bunkers are large structures that are strewn throughout Firmament.
I authored the bunkers with modularity in mind - they are all split into sliced cross-sections that can be assembled into multiple different variations quickly and easily.
The bunkers utilize the Snapping Actors base class for all of the back-end snapping logic, which allows for quick placement and construction iteration.