Specular Highlights

Genesis decouples specular from the PBR roughness pipeline so you can tune the highlight independently of the rest of the lighting model. Pick from GGX, Blinn-Phong, anisotropic, or a hard toon shape, and tint each one without affecting albedo.

When to use it

Metals — GGX with low roughness; intensity follows energy conservation.
Hair and brushed metal — anisotropic, stretched along the tangent.
Toon characters — hard toon spec that reads as a single ink shape.
SFX — disable specular entirely on dissolves, holograms, and wireframes.

Difference from Iridescence

Specular Highlights uses a single tint. Iridescence shifts the highlight color along the view angle. They can stack — iridescence colorizes whichever lobe model you pick here.

Modes

GGX — the physically grounded default; pairs with metallic/smoothness inputs and the URP standard BRDF.
Stylized / Toon — a smoothstep against NdotH produces a hard shape. Pairs with Cel Shading for the canonical toon look.
Anisotropic — stretches the lobe along the tangent or bitangent for hair, brushed metal, and silk.

Screenshot

Three identical spheres under the same light, one per specular model — a soft GGX lobe, a hard-edged Stylized toon shape, and a stretched Anisotropic streak — each labelled with its model name.

features/specular/specular-models.png

A soft, energy-conserving lobe scaled by roughness.

A hard-edged ink shape with a single threshold and ink-toned tint.

GGX (PBR)

Toon · Stepped

The same light and roughness; only the specular model changes. Drag to compare.

Properties

Inspector label	Shader property	Type	Default	Description
Specular Model	_SpecularModel	Enum	GGX	GGX, BlinnPhong, Stylized, or Anisotropic.
Specular Color	_SpecularColor	Color	RGB(1,1,1)	Highlight tint.
Power	_SpecularPower	Float (1–256)	32	Hardness for Blinn-Phong and Stylized.
Smoothness	_SpecularSmoothness	Float (0–1)	0.5	Roughness for GGX. 0 = mirror, 1 = matte.
Intensity	_SpecularIntensity	Float (0–8)	1.0	Overall lobe strength.
Anisotropy	_AnisotropyAmount	Float (-1–1)	0.0	Negative stretches along the bitangent.
Step Threshold	_SpecularStepThreshold	Float (0–1)	0.5	Stylized mode: where the hard edge sits.
Step Smoothness	_SpecularStepSmoothness	Float (0–1)	0.02	Anti-alias width of the toon edge.

Usage

Pick the Specular Model that matches the surface — GGX for most things, Stylized for toon.
Set Specular Color to the light tint (white for sunlight, warm for fire, cool for moon).
Tune Power or Smoothness until the shape reads right.
For hair, enable Anisotropic and verify the mesh tangents are aligned along the strand.


material.SetFloat("_SpecularModel", 2);          // Stylized
material.SetFloat("_SpecularStepThreshold", 0.7f);
material.SetColor("_SpecularColor", new Color(1f, 0.95f, 0.85f));

Tips & gotchas

Anisotropic requires mesh tangents; Unity will not generate them for procedural meshes, so recalculate or import with tangents enabled.
Stylized spec ignores Smoothness — use the Step Threshold instead.
GGX is the only model that obeys energy conservation; the others can over-brighten if pushed.
GGX is fine on mobile, but anisotropic adds 2–3 ALU per pixel, so budget accordingly.

Cel Shading — pair with stylized spec for the toon stack.
Rim Lighting — fresnel edge layered on top of spec.
Iridescence — view-angle color shift on the highlight.
MatCap — fake spec without a light source.