New way of handling lights and materials.

disk.hpp

@@ -14,19 +14,16 @@ public:
   float m_radius;
   
   Disk(): m_radius(1.0f) {
-    rho = 0.0f;
     m_point = vec3(0.0f);
     m_normal = vec3(0.0f, 1.0f, 0.0f);
   }
 
   Disk(float x, float y, float z, float nx, float ny, float nz, float _r): m_radius(_r) {
-    rho = 0.0f;
     m_point = vec3(x, y, z);
     m_normal = normalize(vec3(nx, ny, nz));
   }
 
   Disk(vec3 _p, vec3 _n, float _r): m_radius(_r) {
-    rho = 0.0f;
     m_point = _p;
     m_normal = normalize(_n);
   }