Get the plugin
Get it on Fab.
Unreal Engine 5 · full C++ and shader source. Questions or studio & multi-seat licensing: [email protected].
Feature reference
Every feature, documented field by field.
Pixel-level cel-shading — broken down into the renders you'd ship, the
ACelshadingVolume field that drives each one, and the matching
r.Celshading.* CVar.
Pipeline-aware shading
Lumen GI, shadow maps, exponential height fog, volumetric fog and volumetric lights all feed into the cel-shaded output. The pass reconstructs and re-applies fog around quantization so colors stay clean. No GBuffer override, no PostProcess-Material double-fog hack.
Per-actor opt-in or Non-Stencil Full-screen
Two targeting modes. Set CustomDepth Stencil Value on a mesh component (any slot 1..255)
to opt that actor in. Or flip bAffectWholeScreen to skip per-actor setup entirely
and process every visible pixel.
Zone Overrides
Each ACelshadingVolume can drive the level's atmosphere while the camera is inside
its bounds — three independent channels in one actor:
- Directional light (Sun): intensity, color, indirect bounce, volumetric scattering, source angle, rotation. Walk between zones and the values blend smoothly instead of snapping — ideal for indoor/outdoor transitions or per-slot warm/cool suns.
- Sky Light: intensity and color. Cool a cave with one volume, warm the courtyard with the next — no Level Sequence, no PostProcess hack, no second sky light actor.
- Exponential Height Fog: density, height falloff, inscattering color, directional color, start & cutoff distance, height. The cel pass is fog-aware on top: fog is reconstructed before quantization, so banding stays clean even with thick haze.
Every field is individually opt-in via its bOverride_* bit and follows the same
SpatialFalloff as the rest of the volume. When the camera leaves every overriding
volume, the level's own sun, sky and fog values come back.
Color-aware outline + Outside halo
Adaptive Laplacian outline INSIDE the silhouette (creases, depth jumps) plus an optional
OUTSIDE halo wrapping the actor. The inside outline can color-tint by the underlying surface
(anime self-shadow line look). The outside halo runs as a second compute pass that samples
the cel-shaded silhouette pixel directly, so it carries every internal effect — band
quantization, SpecularHighlightColor blik, rim glow, fog - as a single line
around the actor. Zero cost when off (OutsideOutlineThickness=0):
second pass is not dispatched.
Volume style blending
Drop ACelshadingVolume actors. Bounded volumes use a smooth SpatialFalloff
around their box; overlapping volumes sort by BlendPriority and blend per-field. The
workflow mirrors PostProcessVolume — the same mental model your art team already uses.
Surface response: Metallic & Emissive
The cel pass treats different surface types as different surface types. Two dedicated response paths preserve material identity through quantization:
- Metallic: the lit side of metallic surfaces is lifted, shadows are floored so they don't crush to black, and a tinted specular highlight is clamped to the brightest band — chrome rims and sword blades read correctly next to matte cel-shaded surfaces.
- Emissive:
emissive pixels punch through cel quantization without bleeding into neighboring bands.
Unlit materials are kept out of the bands automatically. On lit materials, tag glowing
areas by routing
1 − EmissiveMaskinto the Ambient Occlusion output — the cel pass reads it as the emissive marker, so no GBuffer override or extra texture is required — or lower the brightness cutoff to catch very bright pixels automatically. A multiplier sets the glow strength, and a dark-side boost keeps emissives readable when they sit in shadow.
Both paths are optional and per-zone — you can mix matte cel surfaces, glossy cel metals and glowing cel emissives in the same volume.
Halftone (manga screentone)
Manga-style dot overlay. A regular dot grid is drawn over the cel-shaded fill — dots grow in shadow areas and fade out in the lit zone. Configurable cell pitch, angle, threshold, softness, opacity and color. Branch on the master toggle is GPU-uniform, so the entire block costs zero when disabled.
Band mask
Comic-inspired ink mask along the band transitions. A screen-space pattern biases each pixel's
brightness up or down by up to one band's width — pixels right at a band boundary are pushed
stochastically to lit or shadow, producing classic comic-book ink in place of crisp cutoffs.
Different from Halftone: this modifies the band assignment itself, not an overlay on top.
Dial BandDitherStretchX from 1 (DOTS) to 5+ (STROKES),
rotate via BandDitherAngle (45° = classic comic ink direction), and dial
BandDitherSoftness from 1 (soft halftone) to 0 (hard pixel edges).
Pattern Depth Reference (sprite-anchor): by default, Halftone + Band Mask cells are screen-fixed (constant pixel size at any distance). Assign an Actor to the volume's PatternDepthReference and the pattern behaves like a billboard sprite locked to that actor's pivot — the cell grid tracks its projected screen position AND zooms outward from its centre as you approach. Strobe-free across the whole stencil slot.
Rim light
Directional screen-space rim. Configurable cone width, hardness, sharpness, and Fresnel weighting. Optional sun-anchored mode — the rim follows the level's directional light direction projected to view space. Optional outline-mix gates rim by the toon outline edge mask for "rim along the line-art" looks.
Rim band dither
The rim's fade-out, redrawn as classic comic-ink halftone. A solid crisp contour hugs the silhouette exactly like before — but its transition into transparency is replaced with size-modulated halftone dots that shrink geometrically as the rim falls off. This is true halftone, not a faded overlay: every pixel is either fully rim or fully empty, and it's the dot radius that scales with the fade — never the opacity. The look is the manga / comic "ink-pen rim" that printed comics use to terminate light edges without going to a soft gradient.
Two parameters, three regimes.
RimDitherSolidEdge (0..1) controls how wide the un-dithered solid contour
is, measured in geometric silhouette-distance (1 − NdotV) so the result is
independent of RimLightHardness and Fresnel exponent — set 0 for full
halftone gradient across the whole rim, set 1 to keep the rim entirely solid (effectively
disabling the halftone for that volume).
RimDitherSoftness (0..1) controls both the dot edge
sharpness and the solid↔dithered boundary width with one knob: 0 gives
razor-crisp ink circles with an instant solid edge (true comic ink), 1 gives a soft halftone
falloff with a wide blend. Independent from BandDitherSoftness so the body and the
rim can have different edge styles in the same volume.
Works at RimLightSharpness = 0. The fade-out signal is sampled
before the optional sharp step() cutoff, so it stays graduated even when
the visible rim is binary. This is the key sanity check that earlier "dither + sharpness" tries
fail: smooth gradient rims and stepped rims both transition cleanly. Reuses the screen-space
cell grid from bBandDither (pattern, scale, angle, stretch, sprite
anchor are all shared with body dither, so the body's ink and the rim's ink animate together) —
zero extra texture loads, no second pattern to tune.
TAA-stable. Dot radius is driven by 1 − NdotV (a per-pixel
geometric value) and cell distance (deterministic from integer pixel coords). No discrete
decision branches, no Side selection — no source of frame-to-frame jitter that
could cause strobing under temporal AA.
Algorithm in one line: FadeProgress = saturate((1 − NdotV) / (1 − SolidEdge)) drives a circular dot of radius = MaxRadius × FadeProgress; pixels with CellDist < radius get the full rim contribution, pixels outside the dot get none. The solid contour is just the saturation plateau where FadeProgress = 1 covers the whole cell. No opacity modulation, no quantizer dependency, no hidden state — what you see is a screen-space dot mask whose radius traces the rim's geometric fade.
Five included presets
Five UCelshadingPreset DataAssets ship in the plugin. Each captures a complete look:
band count, shadow curve, outline, rim, color tinting. Apply directly via the volume's
Active Preset field, or fork and re-save your own.
Predictable GPU cost
One compute dispatch per active stencil slot (any of 1..255 — pay only for what you populate). Empty slots cost zero, and inside a pass the pixels that don't carry the slot's stencil value exit early. Cost scales with resolution and the number of active slots — and it has its own row in the GPU profiler, so you see exactly what you spent on your target hardware.
BUILT TO SHIP
Production tool. Owned source. Direct support from the developer.
Engineered against the post-opaque RDG path, profiled per-pass on consumer GPUs, hardened across UE point releases, and shipped with the full C++ and USF source so your team can audit, profile and extend it on its own terms.
- No engine fork. Drops onto stock Unreal — your team's engine repo stays the engine repo. No 100 GB custom-build to clone, re-fork on every UE point release or mirror in CI/CD.
- Auditable shader path. Compute pass and USF source ship as readable code. No obfuscation, no encrypted blobs — review it, modify it, profile it on your hardware.
- Direct developer contact. Bug reports get answered by the person who wrote the renderer. Fixes ship in the next patch, not the next quarter.
- Engineered for upgrades. Engine version bumps stay routine — no project-wide event, no fork rebase, no marketplace plugins drifting out of sync.