Another interesting possibility offered by the presented approach is to combine real and virtual scene elements. This allows to augment real environments with virtual objects. A first approach consists of virtualizing the real environment and then to place virtual objects in it. This can readily be done using the techniques presented in Section 8.1. An example is shown in Figure 8.14. The landscape of Sagalassos (an archaeological site in Turkey) was modeled from a dozen photographs taken from a nearby hill. Virtual reconstructions of ancient monuments have been made based on measurements and hypotheses of archaeologists. Both could then be combined in a single virtual world.