X-Git-Url: https://gitweb.ps.run/subsurface_scattering/blobdiff_plain/7a181bdf261b620adb266a4f6b485a0afd1ed306..c99ecda7bed596922125f6b1ef1ef2ae8f27703e:/shaders/frag_irradiance.glsl

diff --git a/shaders/frag_irradiance.glsl b/shaders/frag_irradiance.glsl
index 9e14ebe..b985acf 100644
--- a/shaders/frag_irradiance.glsl
+++ b/shaders/frag_irradiance.glsl
@@ -1,19 +1,25 @@
 #version 330 core
 
 in vec3 FragPos;
+in vec3 LocalPos;
+in vec3 Backside;
+in float BacksideIrradiance;
 in vec3 Normal;
 
 out vec4 FragColor;
 
-uniform sampler2D shadowmapTexture;
-
 uniform vec3 objectColor;
 uniform vec3 lightColor;
 uniform vec3 lightPos;
 uniform vec3 viewPos;
+uniform float transmittanceScale;
+uniform int renderState;
+uniform float powBase;
+uniform float powFactor;
 
 void main()
 {
+  // phong lighting
   vec3 norm = normalize(Normal);
   vec3 lightDir = normalize(lightPos - FragPos);
 
@@ -30,5 +36,19 @@ void main()
   vec3 specular = specularStrength * spec * lightColor;
 
   vec3 result = (ambient + diffuse + specular) * objectColor;
+
+  // thickness
+  float distanceToBackside = length(FragPos - Backside);
+
+  if (renderState == 2) {
+    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);
 }