Realistic computer graphics make it possible: Lifelike computer simulations on how light penetrates a room are essential not only for animated films like Toy Story or Cars but also for the automotive industry which is eager to design virtual prototypes on the screen as realistically as possible. Special software programs shall ensure this, but they are very complex. Now, Saarbrücken computer scientists have developed a new approach which is so promising that companies such as Pixar – a renowned specialist in the film sector from the house of Walt Disney – have adopted it in record time.