Spiral Stair Shaft

A newel spiral stair filling a single 2x2m bay, one full 3m storey of wedge treads winding round a stacked stone newel inside a round-cornered shaft wall, open on one bay face so it butts a wall module's doorway.

风格：low-poly, flat-shaded vertex colors, no textures, single shared material, so any set of these merges to one draw call; shares palette and scale with its kit