comments TS SSS

[subsurface_scattering] / shaders / ts_frag.glsl

diff --git a/shaders/ts_frag.glsl b/shaders/ts_frag.glsl
index a0a8457c7bbfc2990209f2152d71d25d956c666e..9362e2a36867c7c6fa347826ffdd0c5bf56649f0 100644 (file)
--- a/shaders/ts_frag.glsl
+++ b/shaders/ts_frag.glsl
@@ -20,42 +20,7 @@ uniform float transmittanceScale;
 \r
 void main()\r
 {\r
-  if (renderState == 0) {\r
-    FragColor = texture(irradianceTexture, UV);\r
-  }\r
-  else if (renderState == 1) {\r
-    vec3 norm = normalize(Normal);\r
-    vec3 lightDir = normalize(lightPos - FragPos);\r
-\r
-    float diff = max(dot(norm, lightDir), 0.0);\r
-    vec3 diffuse = diff * lightColor;\r
-\r
-    float ambientStrength = 0.1;\r
-    vec3 ambient = ambientStrength * lightColor;\r
-\r
-    float specularStrength = 0.5;\r
-    vec3 viewDir = normalize(viewPos - FragPos);\r
-    vec3 reflectDir = reflect(-lightDir, norm);\r
-    float spec = pow(max(dot(viewDir, reflectDir), 0.0), 32);\r
-    vec3 specular = specularStrength * spec * lightColor;\r
-\r
-    vec3 result = (ambient + diffuse + specular) * objectColor;\r
-      \r
-    FragColor = vec4(result, 1.0);\r
-  }\r
-  else if (renderState == 2) {\r
-    vec4 result = vec4(0, 0, 0, 1);\r
-    for (int i = 0; i < 13; i++) {\r
-        vec2 sampleCoords = UV + samplePositions[i] * vec2(1.0/screenWidth, 1.0/screenHeight);\r
-        //vec4 sample = texture(irradianceTexture, sampleCoords)\r
-        //            * texture(shadowmapTexture, sampleCoords);\r
-        vec4 sample = texture(irradianceTexture, sampleCoords);\r
-        vec4 weight = vec4(sampleWeights[i], 1);\r
-        result += sample * weight;\r
-    }\r
-    FragColor = result;\r
-  }\r
-  else if (renderState == 3) {\r
+    // light the model\r
     vec3 norm = normalize(Normal);\r
     vec3 lightDir = normalize(lightPos - FragPos);\r
 \r
@@ -73,28 +38,34 @@ void main()
 \r
     vec3 result = vec3((ambient + diffuse + specular) * objectColor);\r
 \r
+    // sample irradiance as distance to light combined with angle to the light\r
+    // with a Gaussian kernel\r
     vec3 result2 = vec3(0, 0, 0);\r
     for (int i = 0; i < 13; i++) {\r
         vec2 sampleCoords = UV + samplePositions[i] * vec2(1.0/screenWidth, 1.0/screenHeight);\r
         //vec4 sample = texture(irradianceTexture, sampleCoords)\r
         //            * texture(shadowmapTexture, sampleCoords);\r
-        vec3 sample = vec3(texture(irradianceTexture, sampleCoords));\r
+        vec3 sample = vec3(texture(irradianceTexture, sampleCoords)) * diff;\r
         vec3 weight = sampleWeights[i];\r
         result2 += sample * weight;\r
     }\r
 \r
+    // multiply to apply irradiance, sqrt to get values between 0 and 1\r
     result = sqrt(result * result2);\r
     \r
+    // sample texture to get distance from light\r
     vec4 t = texture(irradianceTexture, UV);\r
-\r
     float BacksideIrradiance = t.r; //*100 + t.g + t.b/100;\r
-    \r
+    // and calculate world pos\r
     vec3 Backside = (lightPos + (normalize(FragPos - lightPos) * BacksideIrradiance));\r
     \r
+    // add translucency by amplifying color inverse to the thickness\r
+    // (1 - diff) is part of the irradiance term,\r
+    // if the light hits the object straight at 90°\r
+    // most light is received\r
     float distanceToBackside = length(FragPos - Backside);\r
     if (distanceToBackside != 0)\r
       result += objectColor * exp(2 / pow(distanceToBackside, 0.6)) * transmittanceScale * (1 - diff);\r
 \r
     FragColor = vec4(result, 1);\r
-  }\r
 }\r