X-Git-Url: https://gitweb.ps.run/subsurface_scattering/blobdiff_plain/c99ecda7bed596922125f6b1ef1ef2ae8f27703e..0a5e8172a6ee0e79c81eec21a9966bea9385b249:/shaders/ts_frag.glsl

diff --git a/shaders/ts_frag.glsl b/shaders/ts_frag.glsl
index a0a8457..9362e2a 100644
--- a/shaders/ts_frag.glsl
+++ b/shaders/ts_frag.glsl
@@ -20,42 +20,7 @@ uniform float transmittanceScale;
 
 void main()
 {
-  if (renderState == 0) {
-    FragColor = texture(irradianceTexture, UV);
-  }
-  else if (renderState == 1) {
-    vec3 norm = normalize(Normal);
-    vec3 lightDir = normalize(lightPos - FragPos);
-
-    float diff = max(dot(norm, lightDir), 0.0);
-    vec3 diffuse = diff * lightColor;
-
-    float ambientStrength = 0.1;
-    vec3 ambient = ambientStrength * lightColor;
-
-    float specularStrength = 0.5;
-    vec3 viewDir = normalize(viewPos - FragPos);
-    vec3 reflectDir = reflect(-lightDir, norm);
-    float spec = pow(max(dot(viewDir, reflectDir), 0.0), 32);
-    vec3 specular = specularStrength * spec * lightColor;
-
-    vec3 result = (ambient + diffuse + specular) * objectColor;
-      
-    FragColor = vec4(result, 1.0);
-  }
-  else if (renderState == 2) {
-    vec4 result = vec4(0, 0, 0, 1);
-    for (int i = 0; i < 13; i++) {
-        vec2 sampleCoords = UV + samplePositions[i] * vec2(1.0/screenWidth, 1.0/screenHeight);
-        //vec4 sample = texture(irradianceTexture, sampleCoords)
-        //            * texture(shadowmapTexture, sampleCoords);
-        vec4 sample = texture(irradianceTexture, sampleCoords);
-        vec4 weight = vec4(sampleWeights[i], 1);
-        result += sample * weight;
-    }
-    FragColor = result;
-  }
-  else if (renderState == 3) {
+    // light the model
     vec3 norm = normalize(Normal);
     vec3 lightDir = normalize(lightPos - FragPos);
 
@@ -73,28 +38,34 @@ void main()
 
     vec3 result = vec3((ambient + diffuse + specular) * objectColor);
 
+    // sample irradiance as distance to light combined with angle to the light
+    // with a Gaussian kernel
     vec3 result2 = vec3(0, 0, 0);
     for (int i = 0; i < 13; i++) {
         vec2 sampleCoords = UV + samplePositions[i] * vec2(1.0/screenWidth, 1.0/screenHeight);
         //vec4 sample = texture(irradianceTexture, sampleCoords)
         //            * texture(shadowmapTexture, sampleCoords);
-        vec3 sample = vec3(texture(irradianceTexture, sampleCoords));
+        vec3 sample = vec3(texture(irradianceTexture, sampleCoords)) * diff;
         vec3 weight = sampleWeights[i];
         result2 += sample * weight;
     }
 
+    // multiply to apply irradiance, sqrt to get values between 0 and 1
     result = sqrt(result * result2);
     
+    // sample texture to get distance from light
     vec4 t = texture(irradianceTexture, UV);
-
     float BacksideIrradiance = t.r; //*100 + t.g + t.b/100;
-    
+    // and calculate world pos
     vec3 Backside = (lightPos + (normalize(FragPos - lightPos) * BacksideIrradiance));
     
+    // add translucency by amplifying color inverse to the thickness
+    // (1 - diff) is part of the irradiance term,
+    // if the light hits the object straight at 90°
+    // most light is received
     float distanceToBackside = length(FragPos - Backside);
     if (distanceToBackside != 0)
       result += objectColor * exp(2 / pow(distanceToBackside, 0.6)) * transmittanceScale * (1 - diff);
 
     FragColor = vec4(result, 1);
-  }
 }