atdunbg
6c80693618
TAA subpixel jitter makes rasterized HDR specular highlights oscillate per frame. The old RGB min/max neighborhood clamp re-clamped the converged history against jitter-driven extremes every frame, leaving a periodic residual that the bloom threshold then amplified into visible glow pulsing on static models. - TAA: replace the RGB AABB clamp with YCoCg variance clipping (history clamped toward the stable neighborhood mean +/- 1.25 sigma, intersected with the min/max box as a ghosting upper bound) - Bloom extract: 5-tap cross prefilter before the threshold spreads surviving 1px jitter energy over a ~4x4 footprint so the glow no longer pulses
83 lines
3.2 KiB
GLSL
83 lines
3.2 KiB
GLSL
#version 450
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// TAA resolve：时域抗锯齿。
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// 1. velocity 反推历史像素位置，取历史累积色
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// 2. 方差裁剪（YCoCg）：历史色钳向邻域均值 ± γσ（∩ AABB 极值盒）——
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// 比 RGB min/max 盒稳得多：AABB 盒子被逐帧抖动的高亮像素拽来拽去，
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// 收敛历史持续被重钳 → 周期性残差经 bloom 阈值放大 = 静态模型泛光闪烁
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// 3. mix(cur, hist, alpha) 时域累积
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// 输出写入 TAAColor，它同时也是下一帧的历史（ReadHistory 自引用）。
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layout(location = 0) in vec2 fragUV;
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layout(location = 0) out vec4 outColor;
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layout(set = 0, binding = 0) uniform sampler2D curImage; // 当前帧 HDR
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layout(set = 0, binding = 1) uniform sampler2D velocityImage; // 运动向量（UV 空间）
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layout(set = 0, binding = 2) uniform sampler2D historyImage; // 上一帧累积结果
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// 全屏 pass 通用 push（16B，程序级统一声明，VUID-08878）
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layout(push_constant) uniform PushConstants {
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float exposure; // 与其它全屏 pass 布局一致（本 pass 不用）
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float alpha; // 历史权重（0.9 = 90% 历史）
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float param1;
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float param2;
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} pc;
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// YCoCg 感知空间：亮度/色度分离，方差裁剪不在 HDR RGB 直接做
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//（RGB 各通道独立 σ 会偏色；Y 通道主导几何相关性）
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vec3 RgbToYCoCg(vec3 c) {
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return vec3(0.25 * c.r + 0.5 * c.g + 0.25 * c.b,
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0.5 * c.r - 0.5 * c.b,
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-0.25 * c.r + 0.5 * c.g - 0.25 * c.b);
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}
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vec3 YCoCgToRgb(vec3 c) {
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return vec3(c.x + c.y - c.z,
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c.x + c.z,
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c.x - c.y - c.z);
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}
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void main() {
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vec4 cur = texture(curImage, fragUV);
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vec2 vel = texture(velocityImage, fragUV).xy;
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vec2 histUV = fragUV - vel;
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vec3 result = cur.rgb;
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// 历史采样：越出画面（相机快速平移）直接用当前帧，不累积
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if (all(greaterThanEqual(histUV, vec2(0.0))) &&
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all(lessThanEqual(histUV, vec2(1.0)))) {
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vec3 hist = texture(historyImage, histUV).rgb;
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// 邻域统计（3×3，YCoCg）：均值 m1、均方 m2、极值盒 [mn, mx]
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vec2 ts = 1.0 / vec2(textureSize(curImage, 0));
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vec3 m1 = vec3(0.0);
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vec3 m2 = vec3(0.0);
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vec3 mn = vec3(1e9);
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vec3 mx = vec3(-1e9);
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for (int y = -1; y <= 1; ++y) {
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for (int x = -1; x <= 1; ++x) {
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vec3 c = RgbToYCoCg(texture(curImage, fragUV + vec2(x, y) * ts).rgb);
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m1 += c;
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m2 += c * c;
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mn = min(mn, c);
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mx = max(mx, c);
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}
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}
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m1 /= 9.0;
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m2 /= 9.0;
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vec3 sigma = sqrt(max(m2 - m1 * m1, vec3(0.0)));
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// 方差裁剪盒：均值 ± 1.25σ 再 ∩ 极值盒。历史被钳向"稳定均值"
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// 而非抖动极值 → 收敛残差大幅下降（泛光闪烁的治本点）。
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// 极值盒交集保证不引入邻域外颜色（鬼影上界）
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const float kGamma = 1.25;
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vec3 lo = max(m1 - kGamma * sigma, mn);
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vec3 hi = min(m1 + kGamma * sigma, mx);
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vec3 clamped = YCoCgToRgb(clamp(RgbToYCoCg(hist), lo, hi));
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result = mix(cur.rgb, clamped, pc.alpha);
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}
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outColor = vec4(result, cur.a);
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}
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