15 — GroundedSkybox dial-in.
Cube content reprojected onto a flat disc at world y=0. No explicit ground plane — the "floor" is the cube's lower hemisphere (lit-ground albedo, baked into the Sky-View LUT).
Tune height and radius in the GUI; drag to orbit.
The reflective toggle flips both the floor disc (mirror cube reflection) and the cube bake (Y-mirror sky on the lower hemisphere instead of lit ground albedo) — PBR meshes pick up a clean sky HDRI on their downward IBL.