diff --git a/crates/effects/src/generate.rs b/crates/effects/src/generate.rs index fd5a54123..637cc428e 100644 --- a/crates/effects/src/generate.rs +++ b/crates/effects/src/generate.rs @@ -112,10 +112,19 @@ pub(crate) fn gen_blend(o: Px, g: Px, mode: u32) -> Px { } } +/// 4-Color Gradient's weights are inverse squared distances softened by Blend²: each point +/// weighs 1 / (d² + Blend²) (pixels). Fitted to After Effects 2026 renders at Blend 10, 50, 100 +/// and 300 (power 2.00 at every Blend, softening 0 / 2367 / 9817 / 90127 ≈ Blend²; mean error +/// 0.27/255, max 0.9). Returns Blend² in buffer pixels, never 0. +pub fn four_color_softening(blend: f64, scale: f64) -> f64 { + let b = blend.max(0.0) * scale; + (b * b).max(1e-6) +} + fn four_color(ctx: &EffectCtx, mut b: Buf) -> Buf { let pts: Vec<((f64, f64), [f32; 4])> = (1..=4).map(|i| (b.to_px(ctx.params.v2(&format!("positionsColors/point{i}"))), ctx.params.color(&format!("positionsColors/color{i}")))).collect(); - let blend = ctx.params.f("blend").max(1.0); + let k = four_color_softening(ctx.params.f("blend"), b.scale); let jitter = (ctx.params.f("jitter") / 100.0).clamp(0.0, 1.0) as f32; let op = ctx.params.f("opacity") as f32 / 100.0; let mode = ctx.params.e("blendingMode"); @@ -126,7 +135,7 @@ fn four_color(ctx: &EffectCtx, mut b: Buf) -> Buf { let mut wsum = 0.0; for ((qx, qy), c) in &pts { let d2 = (x as f64 + 0.5 - qx).powi(2) + (y as f64 + 0.5 - qy).powi(2); - let w = 1.0 / (d2 / (blend * 100.0) + 1e-6).powf(1.5); + let w = 1.0 / (d2 + k); for i in 0..3 { acc[i] += c[i] as f64 * w; } @@ -423,6 +432,59 @@ mod generator_tests { } } + /// After Effects 2026, 4-Color Gradient defaults (yellow, green, magenta, blue at 10 % / 90 % + /// of a 1920 × 1080 layer) at Blend 100 and 300, here on a tenth-size layer with Blend 10 + /// and 30 (the weights scale with the layer): colours at AE pixels (10x + 5, 10y + 5). + #[test] + fn four_color_blend_matches_after_effects() { + let pts = [ + ("positionsColors/point1", [19.2, 10.8]), + ("positionsColors/point2", [172.8, 10.8]), + ("positionsColors/point3", [19.2, 97.2]), + ("positionsColors/point4", [172.8, 97.2]), + ]; + let cols = [ + ("positionsColors/color1", [1.0, 1.0, 0.0, 1.0]), + ("positionsColors/color2", [0.0, 1.0, 0.0, 1.0]), + ("positionsColors/color3", [1.0, 0.0, 1.0, 1.0]), + ("positionsColors/color4", [0.0, 0.0, 1.0, 1.0]), + ]; + let ae: [(f64, [(i64, i64, [f32; 3]); 5]); 2] = [ + ( + 10.0, + [ + (30, 20, [249.0, 240.0, 15.0]), + (150, 30, [20.0, 208.0, 47.0]), + (60, 90, [213.0, 56.0, 199.0]), + (100, 10, [115.0, 177.0, 78.0]), + (10, 50, [238.0, 145.0, 110.0]), + ], + ), + ( + 30.0, + [ + (30, 20, [236.0, 214.0, 41.0]), + (150, 30, [30.0, 189.0, 66.0]), + (60, 90, [203.0, 67.0, 188.0]), + (100, 10, [117.0, 173.0, 82.0]), + (10, 50, [233.0, 140.0, 115.0]), + ], + ), + ]; + for (blend, samples) in ae { + let mut vals: Vec<(&str, Value)> = pts.iter().map(|(k, v)| (*k, Value::Vec2(*v))).collect(); + vals.extend(cols.iter().map(|(k, v)| (*k, Value::Color(*v)))); + vals.push(("blend", num(blend))); + let o = run_fx("ec.generate.fourcolor", &vals, Image::filled(192, 108, [1.0, 0.0, 0.0, 1.0]), 0.0, EffectEnv::default()); + for (x, y, want) in samples { + let p = o.img.get(x, y); + for c in 0..3 { + assert!((p[c] * 255.0 - want[c]).abs() <= 3.0, "blend {blend} at ({x}, {y}) channel {c}: {} vs AE {}", p[c] * 255.0, want[c]); + } + } + } + } + #[test] fn four_color_none_stays_inside_the_layer_alpha() { // #1381: like the Gradient Ramp, the gradient fills a shape or text, not its bounding box. diff --git a/crates/effects/src/lib.rs b/crates/effects/src/lib.rs index f157e74c2..13a4130d0 100644 --- a/crates/effects/src/lib.rs +++ b/crates/effects/src/lib.rs @@ -91,7 +91,7 @@ pub use sim3::{PgBlit, PgPlan, playground_plan, playground_state}; pub use stylize2::strobe_on; // CPU helpers the GPU kernels share (effectcraft-gpu). pub use blur2::{camera_lens_plain, camera_lens_spans}; -pub use generate::gen_mode; +pub use generate::{four_color_softening, gen_mode}; pub use generate2::pattern_kind as cell_pattern_kind; pub use generate2::{BoltSeg, Contour, Ghost, RadioPlan, Wave, flare_ghosts, lightning_segments, radio_plan}; pub use generate3::{ diff --git a/crates/gpu/src/fx_generate.rs b/crates/gpu/src/fx_generate.rs index 3744ec4fa..0216d3907 100644 --- a/crates/gpu/src/fx_generate.rs +++ b/crates/gpu/src/fx_generate.rs @@ -353,10 +353,10 @@ fn four_color(e: &mut Enc, ctx: &EffectCtx, b: GBuf) -> Option { p.f[i] = [q.0 as f32, q.1 as f32, 0.0, 0.0]; p.f[4 + i] = ctx.params.color(&format!("positionsColors/color{}", i + 1)); } - let blend = ctx.params.f("blend").max(1.0); + let k = effectcraft_effects::four_color_softening(ctx.params.f("blend"), b.scale); let jitter = (ctx.params.f("jitter") / 100.0).clamp(0.0, 1.0) as f32; p.u[0] = [gen_mode(ctx.params.e("blendingMode")), ctx.seed, 0, 0]; - p.f[8] = [(blend * 100.0) as f32, jitter, ctx.params.f("opacity") as f32 / 100.0, 0.0]; + p.f[8] = [k as f32, jitter, ctx.params.f("opacity") as f32 / 100.0, 0.0]; run(e, "gen_fourcolor", &p, b, None, None) } diff --git a/crates/gpu/src/shaders/fx_generate.wgsl b/crates/gpu/src/shaders/fx_generate.wgsl index f46b2f0ba..bca00ce1b 100644 --- a/crates/gpu/src/shaders/fx_generate.wgsl +++ b/crates/gpu/src/shaders/fx_generate.wgsl @@ -500,7 +500,7 @@ fn gen_fourcolor(@builtin(global_invocation_id) gid: vec3) { let dx = f32(p.x) + 0.5 - q.x; let dy = f32(p.y) + 0.5 - q.y; let d2 = dx * dx + dy * dy; - let w = 1.0 / pow(d2 / bl + 1e-6, 1.5); + let w = 1.0 / (d2 + bl); acc += P.f[4 + i].xyz * w; wsum += w; } diff --git a/docs/effects-parity.md b/docs/effects-parity.md index 92f4d419d..97c43bc43 100644 --- a/docs/effects-parity.md +++ b/docs/effects-parity.md @@ -33,7 +33,7 @@ corpus compares renders, each effect is assumed to differ somewhere, and users k | Color Correction | 40 | 40 | Tint, Tritone and Black & White (sliders and Tint) match After Effects 2026 renders (Rec. 601 luminance); Levels (Individual Controls) matches After Effects 2026 in 32 bpc (channel controls before RGB, "Off for 32 bpc Color" unclipped; plain Levels' channel order not measured); Brightness & Contrast (non-legacy) within about 6/255 of After Effects 2026 ramps (negative settings invert the positive curves); Tint has Swap Colors (#963); ACES 2.0 / OCIO 2.5 (26.5); Apply Color LUT (#514) and 32-bpc blending (#494) are closed | | Distort | 39 | 35 | Liquify has no viewer brush; #303 (Mesh Warp drag) and #534 (CC Power Pin Unstretch) are closed | | Expression Controls | 9 | 9 | — | -| Generate | 26 | 25 | Fractal on the CPU (needs f64); #526 (Reset) and #536 (Write-on marks) are closed | +| Generate | 26 | 25 | 4-Color Gradient's Blend matches After Effects 2026 (weights 1 / (d² + Blend²)); Fractal on the CPU (needs f64); #526 (Reset) and #536 (Write-on marks) are closed | | Immersive Video | 12 | 12 | — | | Keying | 12 | 12 | Luma Key and Extract key on Rec. 601 luminance, as After Effects 2026; Key Cleaner approximated; #533 (wire-removal Frame Offset) is closed | | Matte | 6 | 4 | Mocha shape reads our documented JSON, not Mocha's format | @@ -70,6 +70,7 @@ the GPU is performance, not parity. | 2026-10-19 | minor | Brightness & Contrast: negative Brightness / Contrast are the inverse curves of the positive ones (Brightness −40: 20/255 → 6/255 off After Effects 2026), CPU and GPU | | 2026-10-19 | minor | Luma Key: Key Out Brighter / Darker cut hard at Threshold, measured against After Effects 2026 renders of a ramp (CPU and GPU) | | 2026-10-19 | minor | Luma Key and Extract: Rec. 601 luminance (was Rec. 709), measured against After Effects 2026 (CPU and GPU) | +| 2026-10-19 | minor | 4-Color Gradient: each point weighs 1 / (d² + Blend²), measured against After Effects 2026 at Blend 10 / 50 / 100 / 300 (CPU and GPU) | | 2026-10-18 | minor | Tint uses Rec. 601 luminance weights, measured against After Effects 2026 renders of red, green, blue and grey solids (CPU and GPU) | | 2026-10-18 | minor | Exposure converts to linear light with a pure 2.2 power curve, as measured in After Effects (Offset 0.0005 / 0.002 / 0.02 / 0.1 on black: 8 / 15 / 43 / 90), not the piecewise sRGB curve; its sliders take After Effects' ranges (Exposure −100..100, slider −4..4; Offset −2..2, slider −0.5..0.5; Gamma Correction 0.1..10) | | 2026-10-12 | minor | Parameters 3,014 to 3,017 (effects.md); #303, #514, #526, #533–#536 marked closed instead of pending |