added refraction computations to Scene::traceRay()

git-svn-id: svn://anubis/fart/trunk@376 7f9b0f55-74a9-4bce-be96-3c2cd072584d

util/Material.h

@@ -42,7 +42,11 @@ class Material
         void setReflectance(double reflectance) { m_reflectance = reflectance; }
         double getReflectance() const { return m_reflectance; }
 
-        void setRefraction(double refraction) { m_refraction = refraction; }
+        void setRefraction(double refraction)
+        {
+            if (refraction > 0.0)
+                m_refraction = refraction;
+        }
         double getRefraction() const { return m_refraction; }
 
         void setTransparency(double t) { m_transparency = t; }

util/Vector.h

@@ -77,7 +77,7 @@ class Vector
             const double sinT2 = n * n * (1.0 - cosI * cosI);
             if (sinT2 > 1.0)
                 return Vector(0.0, 0.0, 0.0);
-            return (*this) * n - target * (n + sqrt(1.0 - sinT2));
+            return (*this) * n - target * (n * cosI + sqrt(1.0 - sinT2));
         }
 
         Vector getPerpendicular() const