atelier_beam

The lit air in a shaft of morning sun. It shades thin sheared boxes generated one per gap between the shutter slats: edge softens the shaft across its width, falloff thins it as it crosses the room, mouth keeps it hot where it leaves the window, grazing makes it denser where the eye rakes along it rather than through its face, and dust / dust_scale / drift grain it with motes that turn slowly in the light.

It expects uv.x to run 0 at the window to 1 at the far end of the shaft and uv.y to run across its width, which is how the atelier module authors the mesh. It draws with type: blend, so it adds light to whatever is behind it and writes no depth.