Snapping objects to pre-set rotations in Unity
Looks simple, constraining to 45 degree angles, but there's a lot happening behind the scenes. This is letting you move objects close together in-game, and define the rotational-symmetry of the joint, then it constrains and previews automatically. This is allowing any incoming combination of orientations/shapes/positions - so works in VR etc too (VR builds coming later this year).