The Iridescent texture node produces an effect where surfaces appear to gradually change color as the angle and illumination of view changes (figure 1).


Figure 1: The Iridescent node and it's associated parameters


Iridescent Parameters

Base Color - Determines the base color underlying the other iridescent colors.

Primary Color - The first color layer above the base color.

Secondary Color - Provides an additional color layer to mix with the base and primary colors.

Tertiary Color - Provides an additional color layer to mix with the secondary, primary, and base colors.

Thickness Map - Determines the thickness of the color bands.

Thickness Scale - A scale value applied to the thickness map.

Iridescent Exponent - Adjusts the overall shape of the iridescent effect.

Frequency - Determines how many color bands are generated.

Noise Frequency - Adjusts the smoothness of the color bands.

Noise Scale - Determines the scale of the noise parameter.

Period Offset - Adjusts the positioning of the color bands across the surface.

Iridescence Weight - Blend the primary, secondary, and tertiary color bands with the base color.

UVW Transform - Positions, scales, and rotates the surface texture.

Projection - Sets how the texture projects onto the surface.