Hey there, the previous post contains the most “up-to-date” version of this function, you just need to copy it and paste this into a new Material function. Then you just need to drop 3 of them into a new material for complex IOR, one for each RGB color. For simple IOR (like for non-metal materials like glass or plastic), one of them is enough, and it should still give you better control than the default Fresnel node. Come to think of it, maybe 3 are better, if you want link them to something like absorption for glass and water.
I haven´t tested, if that extra output for raytraced specular is still necessary (i hope not), back then it was necessary.
I made a short video showing the current process, that project is a non-raytraced scene, so no RTX is used.
