anchor.diff:                // get ambience, reflectance and indirect radiance
                 tempColor += s.getAmbientCoeff() * ambientLight;
                 //TODO for all light sources, integrate indirect radiance.
  -              tempColor += s.getReflectance(-r.direction, new Point3D(0, 20, 0) - ret.hitPoint); //TODO dummy light source
  +              tempColor += s.getReflectance(-r.direction, r.origin - ret.hitPoint); //TODO dummy light source at camera
   
                 tempColor += s.getIndirectRadiance();
               }
  
positive.code: 
    void _init(Point3D center, vec3 up, num vertOpeningAngle) {
      this.center = center;
      
      num resX = _res.x.toDouble();
      num resY = _res.y.toDouble();
      num aspectRatio = resX/resY;
  
negative.code:    * Zooms in or out depending if the distance is positive or negativ.
     */
    void zoom(num distance);
  
    /// The resolution of this camera.
    vec2 get res;
  }
  