Add sss (subsurfacescattering)

index.html

@@ -101,7 +101,7 @@
         uniform vec3 eyePos;
         uniform sampler2D displace_map;
 
-        vec3 lightPos = vec3(0.,0.,10.); //should be an directional light
+        vec3 lightPos = vec3(0.,0.,10.); //not used in diffuse. diffuse uses a directional light. It is only used for specular glittering.
         vec3 lightColor = vec3(1.0,1.0,1.0);
         
         //using forward difference
@@ -112,10 +112,10 @@
             //calculate normal
             float gridPointDelta = (1. / 256.);
             vec3 currPoint = vec3(0.0,0.0,displace.x);
-            vec3 right = vec3(gridPointDelta,0.0,texture2D(displace_map,vec2(v_uv.x + gridPointDelta,v_uv.y)).x*0.1);
+            vec3 right = vec3(gridPointDelta,0.0,texture2D(displace_map,vec2(v_uv.x + gridPointDelta,v_uv.y)).x*(1./10.));
-            vec3 left = vec3(-gridPointDelta,0.0,texture2D(displace_map,vec2(v_uv.x - gridPointDelta,v_uv.y)).x*0.1);
+            vec3 left = vec3(-gridPointDelta,0.0,texture2D(displace_map,vec2(v_uv.x - gridPointDelta,v_uv.y)).x*(1./10.));
-            vec3 up = vec3(0.,gridPointDelta,texture2D(displace_map,vec2(v_uv.x ,v_uv.y + gridPointDelta)).x*0.1);
+            vec3 up = vec3(0.,gridPointDelta,texture2D(displace_map,vec2(v_uv.x ,v_uv.y + gridPointDelta)).x*(1./10.));
-            vec3 down = vec3(0.,-gridPointDelta,texture2D(displace_map,vec2(v_uv.x ,v_uv.y - gridPointDelta)).x*0.1);
+            vec3 down = vec3(0.,-gridPointDelta,texture2D(displace_map,vec2(v_uv.x ,v_uv.y - gridPointDelta)).x*(1./10.));
 
             //vec3 tangent = normalize(right - currPoint);
             //vec3 biTangent = normalize(up - currPoint);
@@ -126,7 +126,8 @@
 
             vec3 norm = normalize(normal);
             norm.y *= -1.; //Normal y direction is somehow inverted
-            vec3 lightDir = normalize(lightPos - v_fragPos);
+            //vec3 lightDir = normalize(lightPos - v_fragPos);
+            vec3 lightDir = normalize(-vec3(0.0,.0,-1.)); //sun shines in drection of -z
 
             float diff = max(dot(norm,lightDir),0.0);
             vec3 diffuse = diff * lightColor;
@@ -142,13 +143,23 @@
         	float fresnel = R0 + (1. - R0)*pow((1.-dot(norm,reflec)),5.) ;
 
             //vec3 waterColor = vec3(34./255.,154./255.,211./255.);
-            vec3 oceanColor = vec3(0,.04,.04) * 10.; // under-sea colour
+            vec3 oceanColor = vec3(0,.4,.4); // under-sea colour
-	        vec3 skyColor = vec3(1.,1.,1.);
+            vec3 skyColor = vec3(1.,1.,1.);
+            
+            //Subsurface scattering
+            vec3 sssSun = vec3(0.,-50.,-100.0);
+            vec3 tosssSun = normalize(sssSun - v_fragPos);
+            float ssDistortion = 0.6;
+            float sssIntensity = 1.;
+            vec3 halfWay = normalize(tosssSun+norm*ssDistortion);
+            float ssScateringCoef = pow(clamp(dot(toCameraVector,-halfWay),0.0,1.0),5.) * sssIntensity;
 
-            gl_FragColor = vec4(mix(oceanColor,skyColor,fresnel).xyz, 1.);
+            //gl_FragColor=vec4(oceanColor + (oceanColor*ssScateringCoef),1.0); //Display subsurfacecatterting component
-            //gl_FragColor = vec4(result,1.0);
+            //gl_FragColor = vec4((mix(oceanColor,skyColor,fresnel).xyz), 1.); //Just display reflection component
-            //gl_FragColor = vec4(normal,1.0);
+            //gl_FragColor = vec4(diffuse * oceanColor,1.0); //Render only diffuse component
+            //gl_FragColor = vec4(normal,1.0); //show Normal map
             //gl_FragColor = vec4(displace.x,displace.x,displace.x,1.0); //Show Perlin Noise texture deactivate vertex distrotion before
+            gl_FragColor = vec4((mix(oceanColor + (oceanColor*ssScateringCoef),skyColor,fresnel).xyz), 1.0); //All combined
         }
     </script>
     <script id="default-vs" type="x-shader/x-vertex">