雨天的頂棚：落水線與地面的乾溼界線

Design an urban canopy photographed during heavy rain, so the roof's real behaviour becomes visible. Show the shading plane pitched gently to one long side and deliberately given no gutter, so water runs the full width of the surface and leaves the edge as a continuous sheet, falling several metres into a stone channel cut into the paving directly beneath. Detail that falling curtain of water as the image's main event — a bright vertical veil separating the dry sheltered zone from the soaked plaza beyond. Show the boundary on the ground as absolutely sharp: dark saturated paving on one side of the drip line, pale dry paving on the other, with a few figures standing just inside the dry edge watching. Detail the canopy itself as a plain steel plate roof in a dark grey, its underside dry and matte, its upper surface sheeting with moving water. Show the wider scene through the rain as softened and desaturated, buildings reduced to grey masses. Set it in a city plaza with a few umbrellas crossing in the distance. Show flat grey storm light with the water catching what brightness there is. Photorealistic, wet, grey and silver, low eye-level view along the drip line.