Hallo everybody,
I’d like to clarify a concept: I read these kind of lights called in some different modes as Infinite Directional, Sun, Distant…, shouldn’t have any fall off, even if in many 3d sw you can set a fall off for them. I am right? I mean: is right that a distant light, as sun light i.e. , has any (Inverse Square) fall off ?
An in which cases you should (or could, or suggest…) to use anyway a fall off for this kind of lights?
Many thanks for a reply!
Inverse square falloff is technically correct. If your scene scale is right and your light is in the right position, then inverse square will give correct results.
An object 1 meter away from the light will be significantly brighter than one 2 meters away.
However, the sun, compared to your scene, is a really really really long way away, and very very bright.
Imagine an object 1 meter away from the light, and one 1.00000001 meters away from the light.
The difference in brightness will be insiginificant. So, for accurate lighting you have 2 options. Put the lights brightness incredibly high, and put it 92 million miles away in your scene. Or, as the effects of inverse falloff will be almost nothing, turn it off, and set the light’s brightness to how much sunlight would actually be lighting your scene from that much of the sky.
The directional vs point light option is a different option in the software but the same concept. If your light point is 92 million miles away, then the rays will be so close to being parallel, that you might as well use a light that creates them that way.