Question about FP16Scale about deferredtexturing HOT 4 CLOSED

Hey there! I agree that comment could explain things better and be more helpful! The idea for that came from this blog post by Nathan Reed: https://www.reedbeta.com/blog/artist-friendly-hdr-with-exposure-values/#fitting-into-half-float

Basically the maximum range of an fp16 value is insufficient for rendering with physical sunlight values, and so the scale factor effectively "slides" the fp16 range such that it can now fit reflected sunlight. Basically you scale the lighting input values downward, then later on when you're calculating exposure/tone-mapping/etc. you apply the inverse of that scale factor to get things back to the normal range.

from deferredtexturing.

Yup, an "EV" is basically a log2 "stop" in camera terminology, So 10 EV == 2^10, and -10 EV == 2^-10.

from deferredtexturing.

Thanks for the info. So the current scale factor (2^-10) corresponds to the 10EV shift mentioned by Nathan Reed or is it just an arbitrary value?

from deferredtexturing.

Oh, I see. I didn't know EVs are base-2 🙈. Now that makes perfect sense. Thanks again for the clarification and for this great repository 🙇

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