Material Study / Tutorial: Thin Film Pearlescent (Revisited)

[bdesign]

        A few folks have asked me about this recently, so I thought I'd revisit my old WIP Thin Film pearlescent material, try to improve it, and put together a little tutorial on how the effect was achieved. Since the Thin Film material cannot be applied as a label over other materials, the procedure involves, as you can probably imagine, some "trickery". How to create the illusion that the Thin Film is opaque? By using a Flat material (which does not react with light) as a label, visible only on the backside of the geometry (via a Surface Backside Mask node). Then, to create the pearlescent effect, adding a Metallic Paint material (visible only on the front side, with low opacity and high refractive index) as the top layer.
       The new Photographic Image Style was greatly beneficial in bringing back the vibrance of the Thin Film colors, without the need for post, and the Clear-coat Color/Thickness options allowed many more appearance possibilities. These parameters, along with the Base Color, Metal Color, Metal Coverage, Metal Roughness/Flake size/Visibility, and Thin Film Thickness/Refractive Index, allowed for infinite looks. Additionally, some micro noise bump was added to the Thin Film and Metallic Paint base. Lighting plays a crucial role with this effect.

The core procedure is as follows:

1. Create a Thin Film material.

2. Add a Flat material as a label. Plug a Surface Backside Mask node into the Opacity channel.

3. Add a Metallic Paint material as a second (top level) label. Plug the previously created Surface Backside Mask into the Input of a Color To Number node. Set the Output From value to the desired opacity level (.25 in the example), the Output To value to zero, and plug into the Opacity channel.

4. Plug a Color Gradient texture (Gradient Type View Direction, Invert checked) into the Input of an additional Color To Number node. Set the Outut From and Output To values quite high (2.5, 25 in the example). Plug the C2N node into the Clear-coat Refractive Index channel. This will bring back specularity.

5. For the micro bump in the example, a Noise(Texture) node was used, scale.002, Bump Height .02, plugged into both the Thin Film and Metallic Paint Bump channels.

Additional specific values for this example are as follows:

1. Thin Film: Refractive Index 1.5, Thickness 535nm.

2. Metallic Paint: Base Color 98% grayscale, Metal Color 100% white, Metal Coverage .8, Metal Roughness .05, Metal Flake Size 15, Metal Flake Visibility 1, Samples 32.
Clear-coat Color HSV (220,34,84), Clear-coat Roughness 0, Clear-coat Thickness 1.5.

3. Flat material: Color 74% grayscale.

This technique can also be used to create other effects, such as camera lenses, etc.

Example render, matGraph, and Image Style settings below.

Cheers, Eric

[INNEO_MWo]

Impressive

[bdesign]

Thank you, Marco

Cheers,
Eric

[Aneurismone]

Awesome material! does ks 8.2 even have experimental features? been looking around but cant find the checkbox

[bdesign]

Awesome material! does ks 8.2 even have experimental features? been looking around but cant find the checkbox

Thanks very much, Aneurismone Yes, Experimental Features are available, but there is no longer a checkbox for them under Preferences. In order to access them in the Material Graph you'll need to edit the KeyShot .xml file. Close KeyShot. Open the .xml file (found in Documents > KeyShot 8 ) in a text editor such as WordPad, and search for "experimental_features". Set the bool value = "true". Save the file and close the text editor. Restart KeyShot and the Experimental Features will be available under Utilities in the Material Graph.

Cheers,
Eric

[Aneurismone]

Awesome material! does ks 8.2 even have experimental features? been looking around but cant find the checkbox

Thanks very much, Aneurismone Yes, Experimental Features are available, but there is no longer a checkbox for them under Preferences. In order to access them in the Material Graph you'll need to edit the KeyShot .xml file. Close KeyShot. Open the .xml file (found in Documents > KeyShot 8 ) in a text editor such as WordPad, and search for "experimental_features". Set the bool value = "true". Save the file and close the text editor. Restart KeyShot and the Experimental Features will be available under Utilities in the Material Graph.

Cheers,
Eric

Super cool, will try to do this and post my results asap!

[bdesign]

Made a few adjustments to the Metallic Paint material (Metal Coverage = 1, Clear-coat color = HSV (187,98,100), Clear-coat Roughness = .05, Clear-coat Thickness = .5) and added a Color To Number node, with the same Color Gradient input used for the Clear-coat Refractive Index, to the Flat material Color (Output From = .74, Output To = .37) to enhance depth. Rendered with a different lighting environment.

Cheers,
Eric

[Josh3D]

Looks AMAZING Eric. Thanks for sharing your process too!

[Magnus Skogsfjord]

So nice Eric, as always. You've always been the professor with the mat-graph! Proper 'vizardry'. Thanks for sharing the process with us!

[Esben Oxholm]

Yes! Looks awesome Eric.
Bookmarked right there.

[Will Gibbons]

Is it edible? Because this is one appetizing material.

[Eric Summers]

This is incredible, Eric! Wish I had a reason to try it out!

[bdesign]

Looks AMAZING Eric. Thanks for sharing your process too!

Thank you, Josh! Thanks for the Facebook mention as well.

Cheers,
Eric

[bdesign]

So nice Eric, as always. You've always been the professor with the mat-graph! Proper 'vizardry'. Thanks for sharing the process with us!

"Vizardry"... I love it Thanks, Magnus!

Cheers,
Eric

[bdesign]

Yes! Looks awesome Eric.
Bookmarked right there.

Thanks, Esben!

Cheers,
Eric