index of refractive for opaque materials

[moscatelli]

hello guys, I'm new here on the forum and seeking information about the behavior of light, for work as 3D artist and the subject interests me.

 

In physics, we have index of refraction when the incident ray crosses from one environment to another refracting light. However, I came to read about ior (index of refraction) for opaque materials such as gold, metal, etc. ... I'm a little confused, could someone help me??? This parameter affects how the reflected ray?

 

Materials IOR

http://forums.cgsociety.org/archive/index.php/t-513458.html

[Enthalpy]

Metals have some transparency if they're thin, like under 100nm thickness and below for optical frequencies.

There, the index does influence the transmission.

It influences the reflection both if the metal is thin or thick.

 

Because light is attenuated so quickly in metals, tables use to give the index as a complex number.