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?