Full BSDF

leenkx/Shaders/ssrefr_pass/ssrefr_pass.frag.glsl

@@ -12,6 +12,7 @@ uniform sampler2D tex1;
 uniform sampler2D gbufferD;
 uniform sampler2D gbuffer0;
 uniform sampler2D gbufferD1;
+uniform sampler2D gbuffer1;
 
 uniform sampler2D gbuffer_refraction; // ior\opacity
 uniform mat4 P;
@@ -26,7 +27,7 @@ vec3 hitCoord;
 float depth;
 
 const int numBinarySearchSteps = 7;
-const int maxSteps = int(ceil(1.0 / ss_refractionRayStep) * ss_refractionSearchDist);
+const int maxSteps = 50;
 
 vec2 getProjectedCoord(const vec3 hit) {
 	vec4 projectedCoord = P * vec4(hit, 1.0);
@@ -39,45 +40,60 @@ vec2 getProjectedCoord(const vec3 hit) {
 }
 
 float getDeltaDepth(const vec3 hit) {
-	depth = textureLod(gbufferD1, getProjectedCoord(hit), 0.0).r * 2.0 - 1.0;
+	vec2 tc = getProjectedCoord(hit);
+	if (tc.x < 0.0 || tc.x > 1.0 || tc.y < 0.0 || tc.y > 1.0)
+		return -1.0;
+	depth = textureLod(gbufferD1, tc, 0.0).r * 2.0 - 1.0;
 	vec3 viewPos = getPosView(viewRay, depth, cameraProj);
 	return viewPos.z - hit.z;
 }
 
-vec4 binarySearch(vec3 dir) {
+vec4 binarySearch(vec3 dir, float stepSize) {
 	float ddepth;
 	for (int i = 0; i < numBinarySearchSteps; i++) {
-		dir *= 0.5;
-		hitCoord -= dir;
+		stepSize *= 0.5;
+		hitCoord -= dir * stepSize;
 		ddepth = getDeltaDepth(hitCoord);
-		if (ddepth < 0.0) hitCoord += dir;
+		if (ddepth < 0.0) hitCoord += dir * stepSize;
 	}
-	if (abs(ddepth) > ss_refractionSearchDist) return vec4(0.0);
-	return vec4(getProjectedCoord(hitCoord), 0.0, 1.0);
+	if (abs(ddepth) > ss_refractionSearchDist * 0.005) return vec4(0.0);
+	vec2 hitTC = getProjectedCoord(hitCoord);
+	if (hitTC.x < 0.0 || hitTC.x > 1.0 || hitTC.y < 0.0 || hitTC.y > 1.0)
+		return vec4(0.0);
+	return vec4(hitTC, 0.0, 1.0);
 }
 
 vec4 rayCast(vec3 dir) {
-	float ddepth;
-	dir *= ss_refractionRayStep;
+	float stepSize = ss_refractionRayStep * max(1.0, -viewRay.z * 0.1);
+	vec3 startPos = hitCoord;
 	for (int i = 0; i < maxSteps; i++) {
-		hitCoord += dir;
-		ddepth = getDeltaDepth(hitCoord);
-		if (ddepth > 0.0) return binarySearch(dir);
+		hitCoord += dir * stepSize;
+		float dist = length(hitCoord - startPos);
+		if (dist > ss_refractionSearchDist) break;
+		float ddepth = getDeltaDepth(hitCoord);
+		if (ddepth > 0.0) return binarySearch(dir, stepSize);
+		stepSize *= 1.03;
 	}
 	return vec4(texCoord, 0.0, 0.0);
 }
 
 void main() {
     vec4 gr = textureLod(gbuffer_refraction, texCoord, 0.0);
-    float ior = gr.x;
+    float ior = unpackIOR(gr.x);
     float transmittance = gr.y;
     float surfaceDepth = gr.z;
     float d = surfaceDepth * 2.0 - 1.0;
     
     vec4 sceneSample = textureLod(tex, texCoord, 0.0);
-    if (surfaceDepth == 0.0 || transmittance == 0.0 || ior == 1.0) {
+    if (surfaceDepth == 0.0 || surfaceDepth == 1.0) {
+        fragColor = sceneSample;
+        return;
+    }
+
+    vec4 g1 = textureLod(gbuffer1, texCoord, 0.0);
+    if (transmittance == 0.0 || ior == 1.0) {
         vec3 background = textureLod(tex1, texCoord, 0.0).rgb;
-        fragColor.rgb = sceneSample.rgb + background * (1.0 - sceneSample.a);
+        fragColor.rgb = g1.rgb + background * transmittance;
         fragColor.a = 1.0;
         return;
     }
@@ -96,18 +112,18 @@ void main() {
     vec3 refracted = refract(incident, viewNormal, 1.0 / ior);
     if (length(refracted) < 0.001) {
         vec3 background = textureLod(tex1, texCoord, 0.0).rgb;
-        fragColor.rgb = sceneSample.rgb + background * (1.0 - sceneSample.a);
+        fragColor.rgb = g1.rgb + background * transmittance;
         fragColor.a = 1.0;
         return;
     }
     
     hitCoord = viewPos;
 
-    vec3 dir = refracted * (1.0 - rand(texCoord) * ss_refractionJitter * roughness) * 2.0;
+    vec3 dir = normalize(refracted);
     vec4 coords = rayCast(dir);
 
-	vec2 screenEdge = smoothstep(0.0, 0.1, coords.xy) * smoothstep(0.0, 0.1, 1.0 - coords.xy);
-	float screenEdgeFactor = screenEdge.x * screenEdge.y;
+	vec2 screenEdge = smoothstep(0.0, 0.05, coords.xy) * smoothstep(0.0, 0.05, 1.0 - coords.xy);
+	float screenEdgeFactor = max(screenEdge.x * screenEdge.y, 0.05);
 	float refractivity = 1.0 - roughness;
 	
 	float intensity = pow(refractivity, ss_refractionFalloffExp) * screenEdgeFactor * coords.w;
@@ -118,6 +134,6 @@ void main() {
 	
 	vec3 behindColor = mix(straightBackground, refractedBackground, intensity);
 	
-	fragColor.rgb = sceneSample.rgb + behindColor * (1.0 - sceneSample.a);
+	fragColor.rgb = g1.rgb + behindColor * transmittance;
 	fragColor.a = 1.0;
 }