X-Git-Url: https://gitweb.ps.run/subsurface_scattering/blobdiff_plain/a0fdc6d882a1755d0b0607ba3d9bb55e7f8ac006..refs/heads/main:/shaders/frag_irradiance.glsl

diff --git a/shaders/frag_irradiance.glsl b/shaders/frag_irradiance.glsl
index 497bdf0..2a7edec 100644
--- a/shaders/frag_irradiance.glsl
+++ b/shaders/frag_irradiance.glsl
@@ -19,6 +19,7 @@ uniform float powFactor;
 
 void main()
 {
+  // phong lighting
   vec3 norm = normalize(Normal);
   vec3 lightDir = normalize(lightPos - FragPos);
 
@@ -34,22 +35,18 @@ void main()
   float spec = pow(max(dot(viewDir, reflectDir), 0.0), 32);
   vec3 specular = specularStrength * spec * lightColor;
 
-  //float distanceToBackside = length(clamp(FragPos - Backside, vec3(0), vec3(1000)));
-  float distanceToBackside = length(FragPos - Backside);
-  //distanceToBackside = distance(Backside, LocalPos);
   vec3 result = (ambient + diffuse + specular) * objectColor;
 
-  if (renderState == 3)
-    if (distanceToBackside != 0)
-      //result += objectColor * pow(powBase, -pow(distanceToBackside, 2)) * transmittanceScale * (1 - diff);
-      result += objectColor * pow(powBase, powFactor / pow(distanceToBackside, 0.6)) * transmittanceScale * (1 - diff);
-  // if (renderState == 3) {
-  //   //result = Backside;
-  //   //result = LocalPos;
-  //   result = vec3(distanceToBackside);
-  // }
+  // thickness
+  float distanceToBackside = length(FragPos - Backside);
 
+  if (distanceToBackside != 0) {
+    // 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
+    result += objectColor * pow(powBase, powFactor / pow(distanceToBackside, 0.6)) * transmittanceScale * (1 - diff);
+  }
     
   FragColor = vec4(result, 1.0f);
-  //FragColor = vec4(vec3(distanceToBackside), 1);
 }