const QUAD_SIZE: (f32, f32);Expand description
The flat pane over the front of the floor: its size, how far up it hangs, how far in front of the origin, and how bright it is.
It hangs just above the crests of the relief, because a polygon light is an area source: the closer it sits to what it lights, the sharper the edge of its patch, and lifted high it would only wash the whole floor.