Hello Everybody! so I have been learning a lot about PBR materials and their uses, and that f0 and IOR is one of the essential things to achieve a realistic effect on materials. so I have figured out how to obtain f0 values from IOR online but have not found easy f0 from IOR calculators. some calculators give the IOR to f0 conversion but require more values which I do not know. can somebody help me with this?
Replies
There's a few cases where you may need to manually force IOR values, but they're pretty rare.
What renderer are you using?
Specular (f0)= ( ( IOR − 1 ) / ( IOR + 1 ) ) ²
that puts acrylic (IOR 1.49) at 0.0387 which is 0.5 which is what everyone works with.. (the 0-1 range in a specular/specular level map being 0.0 - 0.08 normalised)
poopipe I know the formula and the process to derive f0 from IOR and using math to derive IOR if f0 value is present.
but that I feel is the long way. there are many calculators present online but i do not know how to use them, that is my problem.
with a metal/rough workflow there is usually a separate specular level channel available - you can pump the dielectric specular values into that.
unreal has it, substance supports export although I'm not sure if they've actually attached it to the shaders yet (we use our own shaders)
its left out in most cases because it's a lot cheaper to leave it out and for the vast majority of surfaces at game type view distances it really doesn't matter.