This tutorial discusses the Spatial Augmented Reality (SAR) concept, its advantages and limitations. It will present examples of state-of-the-art display configurations, appropriate real-time rendering techniques, details about hardware and software implementations, and current areas of application. Specifically, it will describe techniques for optical combination using single/multiple spatially aligned mirror-beam splitters, image sources, transparent screens and optical holograms. Furthermore, it presents techniques for projector based augmentation of geometrically complex and textured display surfaces, and (along with optical combination) methods for achieving consistent illumination and occlusion effects. Emerging technologies that have the potential of enhancing future augmented reality displays will be surveyed.