7 - Visual Rendering

Summary

This chapter addresses visual rendering, which specifies what the visual display should show through an interface to the virtual world generator (VWG). Sections 7.1 and 7.2 cover basic concepts at the core of computer graphics, and VR-specific issues. They mainly address the case of rendering for virtual worlds that are formed synthetically. Section 7.1 explains how to determine the light that should appear at a pixel based on light sources and the reflectance properties of materials that exist purely in the virtual world. Section 7.2 explains rasterization methods, which efficiently solve the rendering problem and are widely used in specialized graphics hardware, called GPUs. Section 7.3 addresses VR-specific problems that arise from imperfections in the optical system. Section 7.4 focuses on latency reduction, which is critical to VR, so that virtual objects appear in the right place at the right time. Otherwise, side effects could arise, such as VR sickness, fatigue, adaptation to flaws, or an unconvincing experience. Section 7.5 explains rendering for captured rather than synthetic virtual worlds. This covers VR experiences that are formed from panoramic photos and videos.