Gooch Shading

Gooch Shading replaces the standard diffuse lerp-to-black with a lerp between a cool and a warm color — the trick that gives medical diagrams and engineering blueprints their distinctive feel. Genesis exposes it as a swappable diffuse model you can drop on any Lit material.

When to use it

Technical illustration — engineering or medical visualization where shape clarity matters more than realism.
Concept renders produced in-engine rather than a 2D pipeline.
Stylized characters that need warm/cool grading baked into the diffuse rather than a post-process LUT.
Explainer content where shape readability beats photorealism.

Difference from Color Adjustments

Color Adjustments grades the final output uniformly. Gooch grades the diffuse term by light direction — lit faces gain warmth, shadowed faces gain cool — so the effect tracks the geometry, not the camera.

How it works

Genesis remaps NdotL from [-1, 1] to [0, 1], then blends _GoochCool and _GoochWarm using that weight. The result is mixed with the albedo by _GoochBlend. Because shadows never reach black, Gooch produces a soft, illustrative look without losing form.

Standard NdotL — the surface darkens toward black in shadow.

The surface lerps from warm (lit) to cool (shadow), never reaching black.

Lambert

Gooch

Standard Lambert against Gooch's cool-to-warm gradient. Drag to compare.

Properties

Inspector label	Shader property	Type	Default	Description
Warm Color	_GoochWarm	Color	RGB(1.0, 0.85, 0.55)	Tint applied to lit surfaces.
Cool Color	_GoochCool	Color	RGB(0.20, 0.30, 0.55)	Tint applied to shaded surfaces.
Warm Albedo Mix	_GoochAlpha	Float (0–1)	0.25	Albedo influence on the warm side.
Cool Albedo Mix	_GoochBeta	Float (0–1)	0.50	Albedo influence on the cool side.
Blend	_GoochBlend	Float (0–1)	1.0	Mix between Gooch and the base diffuse model.

Usage

Switch the Diffuse Model to Gooch under Rendering Modes.
Pick a complementary warm/cool pair — orange/blue is the classic, but red/teal and yellow/violet also work.
Raise Warm/Cool Albedo Mix to let the albedo bleed through; keep them low for the pure blueprint look.
Combine with Outline for full illustrative renders.


material.SetColor("_GoochWarm", new Color(1.0f, 0.78f, 0.40f));
material.SetColor("_GoochCool", new Color(0.18f, 0.28f, 0.62f));
material.SetFloat("_GoochBlend", 1.0f);

Tips & gotchas

Gooch is non-physical and will not energy-conserve. Pair it with a low specular intensity to avoid over-brightening.
Shadows never reach black by design. If you also enable Cel Shading, set the cel shadow color to a darker cool to recover contrast.
Light probes still feed in — the SH term sits on top of the Gooch gradient, so heavily colored probes tint both ends.
It pairs well with Outline for the canonical technical-illustration combo.

Cel Shading — quantize the Gooch gradient into bands.
Outline — finish the illustrative stack.
Rendering Modes — Gooch is a Lit-mode diffuse model.
Color Adjustments — global grading on top.