Screen Space Outline

Screen Space Outline detects edges by sampling the Depth Texture and normal buffer, producing strokes that wrap silhouettes, normal creases, and inner edges with a single full-screen pass. Unlike inverted-hull outlines (which live inside the material), this module sees the whole scene — foreground props get outlined against background props, and inside-mesh creases ink themselves naturally. Screen Space Outline is an optional module added through the Renderer Feature Installer.

Video

A camera moving through a scene mixing several shader types, with clean black outlines inking every silhouette, inter-object edge, and inner crease consistently regardless of which shader each object uses.

modules/screen-space-outline/sso-scene.mp4

Depth and normal edge detection inking a whole scene in one pass.

When to use it

Cel-shaded projects that want comic-book outlines everywhere.
Scenes mixing many shaders (Genesis + URP Lit + custom Shader Graph) — one module inks them all.
Projects that cannot afford inverted-hull duplication on dense meshes.

How it works

Two operators run per pixel:

A depth difference between neighbors detects silhouettes and inter-object edges.
A normal difference detects inner creases on the same mesh.

Both feed a Roberts Cross kernel; the maximum of the two becomes the outline mask. The mask is multiplied by an artist-authored color and composited over the lit frame.

Renderer Feature setup

Open Window → Genesis → Renderer Feature Installer and enable Screen Space Outline.
Ensure the URP Renderer has both Depth Texture and Normals enabled (the Installer toggles them for you).
Pick a preset: Anime, Comic, or Technical.
Add the Genesis SS Outline Volume override for global tuning.

Settings

Inspector label	Shader property	Type	Default	Description
Outline Color	_OutlineColor	Color	RGB(0, 0, 0)	Multiplied over edges. A desaturated dark blue reads well in warm scenes.
Thickness	_OutlineThickness	Float	1.0	Pixel width of the stroke at 1080p; scaled by reference resolution.
Depth Threshold	_DepthThreshold	Float	0.02	Depth difference required to count as an edge. Higher reduces false positives.
Normal Threshold	_NormalThreshold	Float (0–1)	0.4	Cosine threshold for normal edges. Lower catches more inner creases.
Depth Fade	_DepthFade	Float	50	World distance over which outlines fade out.
Angle Sensitivity	_AngleSensitivity	Float	1.0	Boosts edges seen at grazing angles.

Performance & quality

Cost is constant per pixel and does not scale with mesh count.
Half-resolution mode halves the pass cost; at 4K this is a significant win.
For thicker stylized strokes, prefer multiple Roberts Cross taps over a wider kernel — it produces fewer false positives.

Transparent objects do not write to the Depth/Normals textures by default. Enable Render Transparents to Depth in the Genesis material’s Shadow Configuration if you need outlines on glass.

Tips & gotchas

For anime line-weight variation, drive Thickness from a fullscreen mask (e.g. a hand-drawn line-thickness texture).
Combine with Outline (inverted-hull) for hero characters — the per-material outline adds an artist-tunable inner stroke while the module handles inter-object edges.