Iridescence Shader

[jasone.phillips]

I'm trying to create an iridescent shader that has a much stronger coloration than the Thin Film feature. I've tried using the thin film to produce this effect but it's just too light on the surface. I've tried tweaking the film thickness, the IOR, etc. and the effect just isn't strong enough. I'm sure I'm missing something as there are examples on the site showing what I want, but I can't reproduce it using the standard shader.

I even tried creating a shader using a tutorial from Maya, but some of the nodes don't exist anymore in Arnold 5, or are not available for C4D. I've searched this and every other site I can think of for creating it, and have failed.

[jasone.phillips]

Okay, I'm realizing now that the combination of both an RGB ramp (piped to the color channel) and the thin film attribute actually gets pretty good results. Not a true iridescence, but good enough for now. If anyone has a thought about how to create an accurate version I'd love to hear it.

[lee_griggs]

Glad you got it to work. Not sure which Thin Film you are using? There is Thin Film in the Standard Surface shader or there is a specific Thin Film shader (deprecated).

[jasone.phillips]

Hi Lee, I'm using the Thin Film built-in to the standard shader. I'm doing my best to stay away from deprecated stuff. I ended up using a rainbow gradient with the thin film feature. Tweak, tweak, and I finally got something usable for my purposes. I'd love to have a richer solution though.

If someone has something based on this, I'd like to see how it's done in Arnold 5. https://youtu.be/Dyh9_inNuI0

[lee_griggs]

Nice video.

>I'd love to have a richer solution though.

Did you try a Facing Ratio shader and/or color correct shaders? Can you screengrab your shader setup/render?

[jasone.phillips]

c4dtoa-iridescence.jpg

Here is the setup for this mat. The example for Maya that I saw used the facing ratio, but I'm too new to Arnold and couldn't figure out what to connect it to. The nodes that he referenced don't seem to exist in my version.