My image shows a room in which there is an amber pedestal with a crystal ball on top. The wall opposite to the viewer is coppery, and the ceiling is golden and shinny. There is also a marble column on the corner. A vitreau window also is present in one of the walls. The floor is made out of tiles of two colors and is polished such that it reflects light. The scene is illuminated with three light sources: two "artificial" lights (one from the top right side, another one from the left), and "sun" light coming through the vitreau window. Reflection and refraction can be seen all over the scene in a way that look real. I throw more than one ray per pixel, and compute the final intensity value for that pixel as the average of the intensity of all those rays.