Prevent double multiplication of Fresnel.

src/6.pbr/1.1.lighting/lighting.cpp

@@ -95,10 +95,10 @@ int main()
         glm::vec3( 10.0f, -10.0f, 10.0f),
     };
     glm::vec3 lightColors[] = {
-        glm::vec3(5.0f, 5.0f, 5.0f),
-        glm::vec3(5.0f, 5.0f, 5.0f),
-        glm::vec3(5.0f, 5.0f, 5.0f),
-        glm::vec3(5.0f, 5.0f, 5.0f)
+        glm::vec3(2.0f, 2.0f, 2.0f),
+        glm::vec3(2.0f, 2.0f, 2.0f),
+        glm::vec3(2.0f, 2.0f, 2.0f),
+        glm::vec3(2.0f, 2.0f, 2.0f)
     };
     int nrRows    = 7;
     int nrColumns = 7;

src/6.pbr/1.1.lighting/pbr.frag

@@ -103,7 +103,7 @@ void main()
         float NDF = DistributionGGX(N, H, roughness);   
         float G   = GeometrySmith(N, V, L, roughness);      
            
-        vec3 nominator    = NDF * G * F;
+        vec3 nominator    = NDF * G * F; 
         float denominator = 4 * max(dot(V, N), 0.0) * max(dot(L, N), 0.0) + 0.001; // 0.001 to prevent divide by zero.
         vec3 brdf = nominator / denominator;
 
@@ -111,7 +111,7 @@ void main()
         float NdotL = max(dot(N, L), 0.0);        
 
         // add to outgoing radiance Lo
-        Lo += (kD * albedo / PI + kS * brdf) * radiance * NdotL; 
+        Lo += (kD * albedo / PI + brdf) * radiance * NdotL;  // note that we already multiplied the BRDF by the Fresnel (kS) so we won't multiply by kS again
     }   
     
     // ambient lighting (note that the next IBL tutorial will replace 

src/6.pbr/1.2.lighting_textured/pbr.frag

@@ -138,7 +138,7 @@ void main()
         float NdotL = max(dot(N, L), 0.0);        
 
         // add to outgoing radiance Lo
-        Lo += (kD * albedo / PI + kS * brdf) * radiance * NdotL; 
+        Lo += (kD * albedo / PI + brdf) * radiance * NdotL; // note that we already multiplied the BRDF by the Fresnel (kS) so we won't multiply by kS again
     }   
     
     // ambient lighting (note that the next IBL tutorial will replace