Update leenkx/Shaders/sss_pass/sss_pass.frag.glsl

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2025-07-22 23:20:35 +00:00
parent 7ae458a9dd
commit a318e08072

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@ -1,6 +1,7 @@
//
// Copyright (C) 2012 Jorge Jimenez (jorge@iryoku.com)
// Copyright (C) 2012 Diego Gutierrez (diegog@unizar.es)
// Copyright (C) 2025 Onek8 (info@leenkx.com)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
@ -33,6 +34,14 @@
// policies, either expressed or implied, of the copyright holders.
//
// TODO:
// Add real sss radius
// Add real sss scale
// Move temp hash, reorganize shader utility functions
// Add compiler flag for quality presets or with samples parameter
// Clean up + Document comment
#version 450
#include "compiled.inc"
@ -49,67 +58,93 @@ out vec4 fragColor;
const float SSSS_FOVY = 108.0;
// Separable SSS Reflectance
// const float sssWidth = 0.005;
// Temp hash func -
float hash13(vec3 p3) {
p3 = fract(p3 * vec3(0.1031, 0.1030, 0.0973));
p3 += dot(p3, p3.yzx + 33.33);
return fract((p3.x + p3.y) * p3.z);
}
vec4 SSSSBlur() {
// Quality = 0
const int SSSS_N_SAMPLES = 11;
vec4 kernel[SSSS_N_SAMPLES];
kernel[0] = vec4(0.560479, 0.669086, 0.784728, 0);
kernel[1] = vec4(0.00471691, 0.000184771, 5.07566e-005, -2);
kernel[2] = vec4(0.0192831, 0.00282018, 0.00084214, -1.28);
kernel[3] = vec4(0.03639, 0.0130999, 0.00643685, -0.72);
kernel[4] = vec4(0.0821904, 0.0358608, 0.0209261, -0.32);
kernel[5] = vec4(0.0771802, 0.113491, 0.0793803, -0.08);
kernel[6] = vec4(0.0771802, 0.113491, 0.0793803, 0.08);
kernel[7] = vec4(0.0821904, 0.0358608, 0.0209261, 0.32);
kernel[8] = vec4(0.03639, 0.0130999, 0.00643685, 0.72);
kernel[9] = vec4(0.0192831, 0.00282018, 0.00084214, 1.28);
kernel[10] = vec4(0.00471691, 0.000184771, 5.07565e-005, 2);
const int SSSS_N_SAMPLES = 15;
vec4 kernel[SSSS_N_SAMPLES];
// color neutral kernel weights to prevent color shifting
kernel[0] = vec4(0.2, 0.2, 0.2, 0.0);
kernel[1] = vec4(0.12, 0.12, 0.12, 0.2);
kernel[2] = vec4(0.09, 0.09, 0.09, 0.4);
kernel[3] = vec4(0.06, 0.06, 0.06, 0.8);
kernel[4] = vec4(0.04, 0.04, 0.04, 1.2);
kernel[5] = vec4(0.025, 0.025, 0.025, 1.6);
kernel[6] = vec4(0.015, 0.015, 0.015, 2.0);
kernel[7] = vec4(0.005, 0.005, 0.005, 2.5);
kernel[8] = vec4(0.12, 0.12, 0.12, -0.2);
kernel[9] = vec4(0.09, 0.09, 0.09, -0.4);
kernel[10] = vec4(0.06, 0.06, 0.06, -0.8);
kernel[11] = vec4(0.04, 0.04, 0.04, -1.2);
kernel[12] = vec4(0.025, 0.025, 0.025, -1.6);
kernel[13] = vec4(0.015, 0.015, 0.015, -2.0);
kernel[14] = vec4(0.005, 0.005, 0.005, -2.5);
vec4 colorM = textureLod(tex, texCoord, 0.0);
// Fetch linear depth of current pixel
float depth = textureLod(gbufferD, texCoord, 0.0).r;
float depthM = cameraProj.y / (depth - cameraProj.x);
// Calculate the sssWidth scale (1.0 for a unit plane sitting on the projection window)
float distanceToProjectionWindow = 1.0 / tan(0.5 * radians(SSSS_FOVY));
float scale = distanceToProjectionWindow / depthM;
// Calculate the final step to fetch the surrounding pixels
vec2 finalStep = sssWidth * scale * dir;
finalStep *= 1.0;//SSSS_STREGTH_SOURCE; // Modulate it using the alpha channel.
finalStep *= 1.0 / 3.0; // Divide by 3 as the kernels range from -3 to 3.
finalStep *= 0.05; //
// Accumulate the center sample:
vec4 colorBlurred = colorM;
colorBlurred.rgb *= kernel[0].rgb;
// Accumulate the other samples
vec3 jitterSeed = vec3(texCoord.xy * 1000.0, fract(cameraProj.x * 0.0001));
float jitterOffset = (hash13(jitterSeed) * 2.0 - 1.0) * 0.15; // 15% jitteR
finalStep *= (1.0 + jitterOffset);
finalStep *= 0.05;
vec3 colorBlurred = vec3(0.0);
vec3 weightSum = vec3(0.0);
colorBlurred += colorM.rgb * kernel[0].rgb;
weightSum += kernel[0].rgb;
// Accumulate the other samples with per-pixel jittering to reduce banding
for (int i = 1; i < SSSS_N_SAMPLES; i++) {
// Fetch color and depth for current sample
vec2 offset = texCoord + kernel[i].a * finalStep;
float sampleJitter = hash13(vec3(texCoord.xy * 720.0, float(i) * 37.45)) * 0.1 - 0.05;
vec2 offset = texCoord + (kernel[i].a + sampleJitter) * finalStep;
vec4 color = textureLod(tex, offset, 0.0);
//#if SSSS_FOLLOW_SURFACE == 1
// If the difference in depth is huge, we lerp color back to "colorM":
//float depth = textureLod(tex, offset, 0.0).r;
//float s = clamp(300.0f * distanceToProjectionWindow * sssWidth * abs(depthM - depth),0.0,1.0);
//color.rgb = mix(color.rgb, colorM.rgb, s);
//#endif
// Accumulate
colorBlurred.rgb += kernel[i].rgb * color.rgb;
// ADJUST FOR SURFACE FOLLOWING
// 0.0 = disabled (maximum SSS but with bleeding), 1.0 = fully enabled (prevents bleeding but might reduce SSS effect)
const float SURFACE_FOLLOWING_STRENGTH = 0.15; // Reduced to preserve more SSS effect
if (SURFACE_FOLLOWING_STRENGTH > 0.0) {
float sampleDepth = textureLod(gbufferD, offset, 0.0).r;
float depthScale = 5.0;
float depthDiff = abs(depth - sampleDepth) * depthScale;
if (depthDiff > 0.3) {
float blendFactor = clamp(depthDiff - 0.3, 0.0, 1.0) * SURFACE_FOLLOWING_STRENGTH;
color.rgb = mix(color.rgb, colorM.rgb, blendFactor);
}
}
colorBlurred += color.rgb * kernel[i].rgb;
weightSum += kernel[i].rgb;
}
return colorBlurred;
vec3 normalizedColor = colorBlurred / max(weightSum, vec3(0.00001));
float dither = hash13(vec3(texCoord * 1333.0, 0.0)) * 0.003 - 0.0015;
return vec4(normalizedColor + vec3(dither), colorM.a);
}
void main() {
if (textureLod(gbuffer0, texCoord, 0.0).a == 8192.0) {
fragColor = clamp(SSSSBlur(), 0.0, 1.0);
}
else {
vec4 originalColor = textureLod(tex, texCoord, 0.0);
vec4 blurredColor = SSSSBlur();
vec4 finalColor = mix(blurredColor, originalColor, 0.15);
fragColor = clamp(finalColor, 0.0, 1.0);
} else {
fragColor = textureLod(tex, texCoord, 0.0);
}
}