Virtual world: real vs. synthetic

Figure 2.14: Using both color and depth information from cameras, a 3D model of the world can be extracted automatically using Simultaneous Localization and Mapping (SLAM) techniques. Figure from [129].

At one extreme, the virtual world could be completely synthetic. In this case, numerous triangles are defined in a 3D space, along with material properties that indicate how they interact with light, sound, forces, and so on. The field of computer graphics addresses computer-generated images from synthetic models, and it remains important for VR; see Chapter 7. At the other extreme, the virtual world might be a recorded physical world that was captured using modern cameras, computer vision, and Simultaneous Localization and Mapping (SLAM) techniques; Figure 2.14. Many possibilities exist between the extremes. For example, camera images may be taken of a real object, and then mapped onto a synthetic object in the virtual world. This is called texture mapping, a common operation in computer graphics; see Section 7.2.