updated scenes/die.fart, moved where backface checking was occurring in main/Scene

git-svn-id: svn://anubis/fart/trunk@217 7f9b0f55-74a9-4bce-be96-3c2cd072584d

main/Scene.cc

@@ -159,15 +159,12 @@ Color Scene::traceRayRecurse(const Ray & ray, int depth, double factor)
         /* compute the Phong lighting for each hit */
         refptr<Material> material = hit.shape->getMaterial();
 
-        /* TODO: make sure this can be removed */
-#if 0
         /* check for backfaces */
-        if (ray.getDirection() % surfaceNormal > 0.0)
+        if (ray.getDirection() % hit.normal > 0.0)
         {
             /* if dot product is positive, this is a back-face */
-            surfaceNormal = -surfaceNormal;
+            hit.normal = -hit.normal;
         }
-#endif
 
         color = computePhong(material,
                              ray,
@@ -252,9 +249,6 @@ Color Scene::computePhong(const refptr<Material> material,
     double shininess = material->getShininess();
     const Color & diffuseColor = material->getDiffuseColor();
     const Color & specularColor = material->getSpecularColor();
-    Vector normal = surfaceNormal;
-    if (normal % viewRay.getDirection() > 0.0)  /* back face */
-        normal = -normal;
 
     for (std::vector< refptr<Light> >::const_iterator it = m_lights.begin();
          it != m_lights.end();
@@ -263,7 +257,7 @@ Color Scene::computePhong(const refptr<Material> material,
         Vector directionToLight = (*it)->getPosition() - surfacePoint;
         directionToLight.normalize();
         Vector reflectedLightDirection =
-            directionToLight.reflect(normal);
+            directionToLight.reflect(surfaceNormal);
 
         Ray surfaceToLight(surfacePoint, directionToLight);
         Color light_contribution =
@@ -274,7 +268,7 @@ Color Scene::computePhong(const refptr<Material> material,
             || light_contribution.b > 0.0 )
         {
             /* calculate the diffuse term */
-            double diffuse_coef = directionToLight % normal;
+            double diffuse_coef = directionToLight % surfaceNormal;
             if (diffuse_coef > 0.0)
             {
                 result += diffuseColor