Holographic Foil / Car Paint / Lenticular reflections

[make-housing]

I've been asked to recreate this holographic foil effect on a 2d plane:

https://media.giphy.com/media/dqLLqZVJtSb0Jwac64/giphy.gif

Specifically the specks picking up different reflections as the card turns.

I think I've got quite close using the Metallic Flakes setting in a Redshift Car Paint shader:

https://media.giphy.com/media/H0ZlEwWe5YDRQKGZeS/giphy.gif

But I really want to be able to define my own noise / pattern.

In this example the reflections are following a pattern that changes with the angle of reflection:

https://media.giphy.com/media/6SygzX0SItLkkwTJvh/giphy.gif

Does anyone have an idea how I would achieve this?

[Dr. Sassi]

Hi make-housing,

I would do that with a Normal Map.

Normal maps are representations of a surface direction. Think of a cube that you like to rotate. Each rotation axis can be expressed in numbers. Colors can be expressed in numbers. In that way, the rotation is expressed with Colors.

If you set it Tangent, the colors of no influence would be R=0.5, G=0.5, and B=1.0. Those numbers are data values and should be expressed in Linear and Raw. If the numbers change, the direction changes.

Flakes are not parallel to the surface (some might) if the colors change while in the Normal channel; the application will use this as a direction. If you like to have it with flat flakes, use on the values a posterize effect.

To increase the glimmer effect, animate the noise.

Render a preview, one time with the Normal channel on and one time off.
https://www.dropbox.com/s/mzibnlkkeff2x5f/CV4_2023_drs_23_TXfl_01.c4d.zip?dl=0

All the best

[Dr. Sassi]

P.S.: for Holographic simulations, perhaps a layered Spectral Shader works better
https://www.dropbox.com/s/hukdqzwlo6gxdfz/CV4_2023_drs_23_TXfl_11.zip?dl=0

Please note that I have used a different Layer in each ".psd" instance.