PBR iridescence shader¶

Time: 45 minutes. Difficulty: Intermediate.

Author an iridescent material in Hypershade for a Blue Morpho-style look. Useful for wings, oil slicks, soap bubbles, and any surface with view-angle-dependent color.

Prerequisites¶

Designer installed.
Mesh3D + a directional light in your scene (see Blue Morpho chapter 7).

Open Hypershade¶

Hypershade > Open Hypershade…. Drag your mesh's material into the graph view.

The pattern¶

Iridescence is the same texture sampled at two hues with a fresnel mix. Where the surface faces the camera, color A dominates; at grazing angles, color B.

Build the graph¶

Drop a Texture node, load your albedo PNG.
Drop a Color node, set to #9333eaff (deep purple).
Drop a Color node, set to #22d3eeff (cyan).
Drop a Mix node. Connect:
input A: the purple Color.
input B: the cyan Color.
factor: a Fresnel node (exponent 4-6).
Drop a Multiply node. Connect:
input A: the Mix output.
input B: the Texture's rgb output.
Connect the Multiply result to PBR Surface > albedo.

Set the PBR Surface's roughness to 0.15 (slight gloss) and metallic to 0.0.

Add specular shift¶

Iridescent surfaces also shift specular highlights. Add a second Mix node feeding PBR Surface > specular_tint from the same Fresnel. The tint shifts blue → magenta with view angle.

Preview¶

The Hypershade preview sphere shows the material live. Orbit (Alt + middle drag): the color sweeps purple → cyan as the sphere rotates.

Apply to the mesh¶

Right-click PBR Surface > Assign to Selection. The mesh in the View Panel updates.

Render¶

Rendering > Render Quality > Preview (12 spp), Rendering > Render Selected. The render captures the iridescence at one specific angle: orbit the camera and re-render for different looks.

Save the material¶

Hypershade > Save Material As… → iridescence.elymaterial. Reuse across projects via Load Material….

Tuning¶

More vibrant: raise both Colors' saturation in OKLab; use lighten and darken to keep perceptual balance.
Sharper transition: raise the Fresnel exponent (6 → 12).
Bandwidth: add a third Color and a second Mix for a three-band iridescence (oil-slick rainbow look).

Export¶

File > Export > .esk Bundle. The material ships with the skin.

What you exercised¶

Hypershade node graph authoring.
Fresnel + Mix as the iridescence pattern.
.elymaterial save / load.
Specular tint as a second iridescence channel.