ctrl_fresnel attributes -need more clarifaction

[oil_on_glass]

does anyone here know what the ctrl_fresnel shader attributes represent -from an artist's/TD's perspective? Here are my inquiries:


Statevector: I assume this is the normalized vector of choice(default being the dot product between the camera and surface normal ie "facing ratio")

IOR: Index of refraction. does this work with the "complex IOR" of metals such as aluminum? My data states that aluminum has an IOR of 1.44 but when I plug this number in, the result doesnt look like what I think it should. this needs more clarifaction in my opinion

Ksmooth: I have no idea what this means or how it relates to other variables. Can someone explain what this does? Does it relate to BRDF/BSDF/Fresnal Reflectance in some fashion?


thanks for any answers/clarifications!

[Decoman]

I do not know much about this, but here is my newbish impression of how the the Ksmooth slider works. Also I believe the various IOR values (anything more than 1.00) have a major effect on how the Ksmooth eventually appear to work as you try it with different Ksmooth-values.

When over 0.5, the "Ksmooth" seem to make the fresel-reflection-effect stronger, limiting the apparant effect of reflectivity more towards the silhouette outline of an orb/ball.

When under 0.5, the "Ksmooth" seem to make the fresnel-reflection-effect weaker, making the reflection-effect apparant on a larger portion of the object, and i guess eventually making the reflection effect appear as equally strong all over.