Michal Iwanicki

there is no such thing as “falloff”!only visible solid angle. For receiver sky, emissive, lights=same

Yes there is falloff. For a area light, solid angle falls off with distance. For sky dome, it does not.

sure,solid angle changes for small emissive surfaces(lights!);but concept of falloff is wrong for area L

sooner you kill concept of falloff and quadratic approx in engine/mental model,the less problems you have:)

unifies everything: lights,dir lights(solid angle +/- constant),emissive surf,cubes,sky

I was trying to make an intuitive argument of why flux is constant under scale in some cases & not others

power/flux from diff area dA falls onto dA/cos(theta) area - unit area gets cos(thata)*dA

point light source with power P, with spherical distribution gives P/(4*pi*r^2) at distance r