SSGI rewrite

leenkx/Shaders/deferred_light/deferred_light.frag.glsl

@@ -379,7 +379,7 @@ void main() {
 
 #ifdef _SSGI
 	vec3 ssgiColor = textureLod(ssgitex, texCoord, 0.0).rgb;
-	fragColor.rgb += ssgiColor * albedo;
+	fragColor.rgb += ssgiColor * basecolor;
 #endif
 
 #ifdef _EmissionShadeless

leenkx/Shaders/ssgi_pass/ssgi_pass.frag.glsl

@@ -28,10 +28,12 @@ in vec2 texCoord;
 out vec4 fragColor;
 
 const float GOLDEN_ANGLE = 2.39996323;
-const int RAY_STEPS = 12;
+const int RAY_STEPS = 6;
+const int BINARY_STEPS = 3;
 
 vec2 getProjectedCoord(const vec3 viewPos) {
 	vec4 projectedCoord = P * vec4(viewPos, 1.0);
+	if (projectedCoord.w <= 0.0) return vec2(-1e5);
 	projectedCoord.xy /= projectedCoord.w;
 	projectedCoord.xy = projectedCoord.xy * 0.5 + 0.5;
 	#ifdef _InvY
@@ -40,16 +42,12 @@ vec2 getProjectedCoord(const vec3 viewPos) {
 	return projectedCoord.xy;
 }
 
-vec3 cosineSampleHemisphere(vec3 n, vec2 rand) {
+float linearZ(const float depth) {
-	float phi = PI * 2.0 * rand.x;
+	return -P[3].z / (depth + P[2].z);
-	float cosTheta = sqrt(1.0 - rand.y);
+}
-	float sinTheta = sqrt(rand.y);
+
-	
+void buildTBN(vec3 n, out vec3 tangent, out vec3 bitangent) {
-	vec3 h = vec3(cos(phi) * sinTheta, sin(phi) * sinTheta, cosTheta);
-	
-	vec3 tangent, bitangent;
 	vec3 absN = abs(n);
-	
 	if (absN.x <= absN.y && absN.x <= absN.z) {
 		tangent = normalize(cross(n, vec3(1.0, 0.0, 0.0)));
 	} else if (absN.y <= absN.z) {
@@ -58,46 +56,70 @@ vec3 cosineSampleHemisphere(vec3 n, vec2 rand) {
 		tangent = normalize(cross(n, vec3(0.0, 0.0, 1.0)));
 	}
 	bitangent = cross(n, tangent);
-	
+}
+
+vec3 sampleHemisphere(vec3 n, vec3 tangent, vec3 bitangent, float phi, float cosTheta) {
+	float sinTheta = sqrt(1.0 - cosTheta * cosTheta);
+	vec3 h = vec3(cos(phi) * sinTheta, sin(phi) * sinTheta, cosTheta);
 	return normalize(tangent * h.x + bitangent * h.y + n * h.z);
 }
 
-vec3 traceRay(vec3 origin, vec3 dir, float maxDist, float minDist) {
+vec3 traceRay(vec3 origin, vec3 dir, float maxDist, float minDist, float jitter) {
 	float stepSize = maxDist / float(RAY_STEPS);
-	vec3 pos = origin + dir * minDist;
+	float rayDist = minDist + stepSize * (jitter - 1.0);
+	vec3 pos = origin + dir * rayDist;
 	
 	float prevDepthDiff = 0.0;
-	float hadValidPrev = 0.0;
+	bool hasPrev = false;
 	
-	for (int i = 1; i <= RAY_STEPS; i++) {
+	for (int i = 0; i < RAY_STEPS; i++) {
 		pos += dir * stepSize;
+		rayDist += stepSize;
 		vec2 uv = getProjectedCoord(pos);
+		if (uv.x < -100.0) return vec3(-1.0);
+		uv = clamp(uv, vec2(0.001), vec2(0.999));
 		
-		vec2 sampleUV = clamp(uv, vec2(0.001), vec2(0.999));
+		float sampleDepth = textureLod(gbufferD, uv, 0.0).r * 2.0 - 1.0;
-		
-		float sampleDepth = textureLod(gbufferD, sampleUV, 0.0).r * 2.0 - 1.0;
 		if (sampleDepth == 1.0) {
-			hadValidPrev = 0.0;
+			hasPrev = false;
 			continue;
 		}
+
+		float depthDiff = pos.z - linearZ(sampleDepth);
+		float thickness = maxDist * 0.075 + rayDist * 0.125;
 		
-		vec3 sampleViewPos = getPosView2(invP, sampleDepth, sampleUV);
+		bool crossed = hasPrev && (prevDepthDiff > 0.0) && (depthDiff <= 0.0);
-		float depthDiff = pos.z - sampleViewPos.z;
+		bool withinThickness = (depthDiff <= 0.0) && (-depthDiff < thickness);
-		float rayDist = length(pos - origin);
-		float thickness = 0.15 + rayDist * 0.25;
 		
-		float crossed = hadValidPrev * step(0.0, prevDepthDiff) * step(depthDiff, 0.0);
+		if (crossed || withinThickness) {
-		float withinThickness = step(abs(depthDiff), thickness);
+			vec3 bPos = pos;
-		
+			vec3 bDir = dir * stepSize;
-		if (crossed > 0.5 || withinThickness > 0.5) {
+			for (int j = 0; j < BINARY_STEPS; j++) {
-			float distWeight = 1.0 - (rayDist / maxDist);
+				bDir *= 0.5;
-			distWeight = max(0.0, distWeight * distWeight);
+				bPos -= bDir;
+				vec2 bUV = getProjectedCoord(bPos);
+				bUV = clamp(bUV, vec2(0.001), vec2(0.999));
+				float bDepth = textureLod(gbufferD, bUV, 0.0).r * 2.0 - 1.0;
+				if (bDepth == 1.0) {
+					bPos += bDir;
+					continue;
+				}
+				if (bPos.z - linearZ(bDepth) > 0.0) bPos += bDir;
+			}
 			
-			return vec3(sampleUV, distWeight);
+			vec2 bestUV = getProjectedCoord(bPos);
+			if (bestUV.x < -100.0) return vec3(-1.0);
+			bestUV = clamp(bestUV, vec2(0.001), vec2(0.999));
+			
+			float hitDist = length(bPos - origin);
+			float distWeight = max(0.0, 1.0 - (hitDist / maxDist));
+			distWeight *= distWeight;
+			
+			return vec3(bestUV, distWeight);
 		}
 		
 		prevDepthDiff = depthDiff;
-		hadValidPrev = 1.0;
+		hasPrev = true;
 	}
 	
 	return vec3(-1.0);
@@ -111,77 +133,77 @@ void main() {
 	}
 
 	vec4 g0 = textureLod(gbuffer0, texCoord, 0.0);
-	vec2 enc = g0.rg;
+	vec3 n = getNor(g0.rg);
-	vec3 n;
+	vec3 basecolor = textureLod(gbuffer1, texCoord, 0.0).rgb;
-	n.z = 1.0 - abs(enc.x) - abs(enc.y);
-	n.xy = n.z >= 0.0 ? enc.xy : octahedronWrap(enc.xy);
-	n = normalize(n);
 
 	vec3 viewNormal = V3 * n;
 	vec3 viewPos = getPosView2(invP, depth, texCoord);
 
 	#ifdef _CPostprocess
-		float radius = PPComp12.y;
+		float radius = PPComp12.y * 2.0;
-		float strength = PPComp12.x;
+		float strength = PPComp12.x * 0.5;
 	#else
-		float radius = ssgiRadius;
+		float radius = ssgiRadius * 2.0;
-		float strength = ssgiStrength;
+		float strength = ssgiStrength * 0.5;
 	#endif
 
-	float noise = fract(52.9829189 * fract(0.06711056 * texCoord.x * 1000.0 + 0.00583715 * texCoord.y * 1000.0));
+	radius = min(radius, max(-viewPos.z / P[1].y, 0.05));
+
+	float noise = fract(52.9829189 * fract(0.06711056 * gl_FragCoord.x + 0.00583715 * gl_FragCoord.y));
 
 	vec3 gi = vec3(0.0);
-	int validSamples = 0;
+	float missWeight = 0.0;
 
 	// min distance to avoid self shadowing artiffacts
 	float minDist = radius * 0.05;
 	
+	vec3 tangent, bitangent;
+	buildTBN(viewNormal, tangent, bitangent);
+	
 	for (int i = 0; i < ssgiSamples; i++) {
-		float fi = float(i) + noise;
+		float phi = float(i) * GOLDEN_ANGLE + noise * PI2;
-		vec2 rand = vec2(
+		float cosTheta = sqrt(max(0.0, 1.0 - (float(i) + 0.5) / float(ssgiSamples)));
-			fract(fi * 0.7548776662 + noise),
+		float jitter = fract(noise + float(i) * 0.618034);
-			fract(fi * 0.5698402909 + noise * 1.5)
-		);
 		
-		vec3 rayDir = cosineSampleHemisphere(viewNormal, rand);
+		vec3 rayDir = sampleHemisphere(viewNormal, tangent, bitangent, phi, cosTheta);
-		vec3 hitResult = traceRay(viewPos, rayDir, radius, minDist);
+		vec3 hitResult = traceRay(viewPos, rayDir, radius, minDist, jitter);
 		
-		if (hitResult.x < 0.0) continue;
+		if (hitResult.x < 0.0) {
+			missWeight += 1.0;
+			continue;
+		}
 		
 		vec2 hitUV = hitResult.xy;
 		float distWeight = hitResult.z;
 		
-		vec3 hitAlbedo = textureLod(gbuffer1, hitUV, 1.0).rgb;
+		vec3 hitN = getNor(textureLod(gbuffer0, hitUV, 0.0).rg);
+		float emitterCos = max(0.0, dot(V3 * hitN, -rayDir));
+		if (emitterCos <= 0.0) {
+			missWeight += 1.0;
+			continue;
+		}
+		
+		vec3 hitAlbedo = textureLod(gbuffer1, hitUV, 0.0).rgb;
 		
 		#ifdef _Sun
-		vec4 hitG0 = textureLod(gbuffer0, hitUV, 0.0);
-		vec2 hitEnc = hitG0.rg;
-		vec3 hitN;
-		hitN.z = 1.0 - abs(hitEnc.x) - abs(hitEnc.y);
-		hitN.xy = hitN.z >= 0.0 ? hitEnc.xy : octahedronWrap(hitEnc.xy);
-		hitN = normalize(hitN);
 		float hitNdotL = max(0.0, dot(hitN, sunDir));
-		vec3 hitRadiance = hitAlbedo * sunCol * hitNdotL;
+		vec3 hitRadiance = hitAlbedo * (sunCol * hitNdotL + vec3(0.4));
 		#else
-		vec3 hitRadiance = hitAlbedo * 0.5;
+		vec3 hitRadiance = hitAlbedo * 0.4;
 		#endif
 		
 		#ifdef _EmissionShaded
 		hitRadiance += textureLod(gbufferEmission, hitUV, 0.0).rgb;
 		#endif
 		
-		gi += hitRadiance * distWeight;
+		gi += hitRadiance * (distWeight * emitterCos);
-		validSamples++;
 	}
 
-	if (validSamples > 0) {
+	gi += basecolor * 0.1 * missWeight;
-		gi /= float(validSamples);
+	gi *= 2.0 * strength / float(ssgiSamples);
-	}
-	
-	gi *= strength;
 
 	#ifdef _EmissionShaded
-		gi += textureLod(gbufferEmission, texCoord, 0.0).rgb * 0.3;
+	gi += textureLod(gbufferEmission, texCoord, 0.0).rgb * 0.3;
 	#endif
 
 	fragColor = vec4(min(gi, vec3(2.0)), 1.0);