Realtime Feather Groom

For those Mystique X-Men fans out there, here's a shot at reproducing a "feather groom" effect in realtime using particles. It's just planar-aligned billboards spawned on a skeletal mesh surface, using geometry info like normal and tangents to control the grooming flow and structure. From there I'm using a sphere from which I sample a signed distance-field to control the "flip-flop" effect from one side to another.