Ok, I think I've come up with a more finalized result. I ended up borrowing from both of your material setups and put it together as a modified phong. Here's what I came up with:
Depends what sort of iridescent you want, really. http://www.pestcontrolcanada.com/Questions/iridescent%20beetle.jpg In the past I've usually just made the specular colour a really strong colour that's fairly opposite the diffuse colour of the material. So for a red material, I'd use a strong bright green highlight. Also…
OH btw LoTekk and others, here Have some Material Functions. I'm building a library of these things, and will eventually be providing documentation. I have a few more things in the works to add. However a material function version of Rodriques' rotation function is in there as "Vailias_Vector_Rotation" (everything is…
This looked like a fun challenge so I thought I'd give it a shot. First off, I tried to emulate the kind of iridescence of this beetle: I think I've been able to recreate the general behavior of the specular color based on viewer angle with a fair bit of accuracy. Screenshot: Material Editor: Specular Network: All in all…