halftone-impact-field

A dirty black-and-white halftone poster being warped by a radial impact, scratched apart, and re-scanned through unstable analog print noise.

Open the editor Group: Signature shaders

What it’s for

halftone-impact-field takes any source, crushes it to a harsh black/white luminance field, then rebuilds it out of warped halftone dots — bright areas become dense white ink, shadows stay black. The dot screen is then bent by a central radial impact (or sucked into a vortex), and finally contaminated with grunge: erased patches, dust, drifting scratches and dragged ink smears. Photocopied punk poster, damaged newspaper halftone, screen-printed ink on black paper — printed, not procedural.

Reach for it when a shot needs to feel like a screen-printed blast poster or a Xerox that has been run too many times: a title card detonating outward from a dot core, a face dissolving into newsprint, a logo shockwaved into arced dot rows. It operates purely on luminance, so it works on any source — video, AI images, text, particles. The master strength dials it from a faint print screen to a full monochrome optical blast.

What it does to a frame

Luminance ink field — aggressive threshold + contrast crush the source to a near-binary black/white field; monochromeBias pushes it to pure mono.
Halftone dot grid — the field is rebuilt as resolution-locked circular dots; radius scales with local ink density, big in highlights, gone in shadows. Glyph-independent, so it never beats the ASCII raster.
Radial impact distortion — a central impact point compresses dot spacing near the core, arcs the rows outward and forms a pulsing white blast bloom radiating like a shockwave.
Vortex swirl — an optional polar twist with radial falloff sucks the dot field into a slow rotating spiral.
Ink damage — layered value-noise grunge: erased blotches gouge ink out, dust speckle adds rogue dots, the grid breaks irregularly and analog.
Drifting scratches — thin near-vertical streaks cut white gaps through the dots and jump-cut between scans rather than sliding.
Directional ink smears — a diagonal poster mode drags the dot field along a chosen axis, partially destroying dots into motion energy.
Unstable re-scan motion — the dot field breathes, the core pulses, grunge crawls and ink density flickers on a quantised step — not smooth liquid motion, but a print being re-scanned.

Where it lives in the app

Canvas effect tray, group Signature shaders. A GL post-process overlay — it runs after the ASCII pipeline on the rendered canvas, so it composites over any layer stack and the dots distort the glyph output directly. It reads strongest on content with clear bright structure against dark areas, because the dot reconstruction needs tonal range. Gate it with a mask layer so only the diegetic screen, subject or title becomes a print blast while the rest of the frame stays intact.

Parameters

Key	Range	Default	Effect
`strength`	0–1	0.85	Master gate — crossfade from untouched source to full halftone blast
`dotScale`	2–64 px	7	Halftone dot pitch in screen pixels
`dotRoundness`	0–1	0.85	Square ↔ circular dot shape
`dotSoftness`	0–0.5	0.06	Dot edge anti-aliasing width
`dotDensity`	0–1	0.55	Coverage response curve — sparse ↔ clumped
`threshold`	0–1	0.5	Black/white split point of the ink field
`contrast`	0–1	0.7	Crush hardness toward pure binary
`focusX`	0–100 %	50	Impact / vortex center X
`focusY`	0–100 %	50	Impact / vortex center Y
`impactStrength`	0–2	1	Radial blast + bloom-core intensity
`radialCompression`	0–4	1.4	How hard dot spacing compresses near the core
`swirlStrength`	-6–6	0	Vortex angular twist (signed)
`swirlRadius`	0.05–1	0.4	Vortex falloff radius
`grungeAmount`	0–1	0.75	Erased-patch + dust ink-damage amount
`scratchAmount`	0–1	0.6	Drifting scratch-streak density
`smearAmount`	0–1	0	Directional ink-smear drag (diagonal mode)
`inkBleed`	0–1	0.3	Soft wet-ink halo around dots
`flickerSpeed`	0–8	2	Quantised re-scan flicker rate (0 freezes)
`monochromeBias`	0–1	1	Push toward pure binary B/W vs rough gray
`smearAngleDeg`	0–360	45	Direction of the ink smear
`mode`	0–3	1 (Radial explosion)	Print · Radial explosion · Vortex swirl · Diagonal smear

Pairs well with

film-grain — adds silver-halide emulsion noise under the dots so the print reads as photographed paper, not clean vector.
phosphor — smears the pulsing blast core into a screen that has been re-scanning the poster for hours.
palette quantize — lock it to one ink colour and the monochrome poster reads as a specific screen-print run.
mask layers — detonate the halftone blast only over the subject or title while the rest of the frame stays intact.