A concrete wall bay with a 3 m by 2.7 m vehicle opening closed by a shutter of thirteen slats. The curtain hangs from a barrel at the head and tilts up and out over it, running in two guide rails that stand proud of the jamb reveals, with a rusted bottom rail and a lifting bar across it. Dimensions 4.02 × 3.54 × 0.59 m (X × Y × Z). Metre units, +Y up, +Z front; origin on the ground at the footprint centre unless stated. Damp conifer forest realism: wet concrete and corroded corrugated steel, weathered pine, dark bark and soil, deep needle green, olive canvas, gunmetal and machined steel, with five emissive colours (amber fire, white floodlight, green status, blue screen, red warning) that also form the loot rarity ladder. Rigid node-transform clips open, close turn named nodes on their own pivots. No skinning, no skeleton, no skin weighting, no collision or navigation data. The barrel above the opening is fixed: the curtain is one rigid leaf, not a coiling slat chain, because a rigid node transform cannot roll a curtain onto a drum.