Simulates crepuscular "god rays" and puffy cumulus lit by a low sun. Real volumetric clouds are rendered by raymarching a 3D noise density field and integrating light scattering along each view ray — an expensive technique. This demo fakes that look cheaply: dozens of soft alpha-blended billboard sprites are clustered into cloud blobs, each puff tinted by the dot product of its offset from the cluster center against the sun direction (warm near the sun, cool in shadow), while additive-blended stretched planes radiating from the sun disc simulate light shafts scattering through haze.