An introduction to parallel rendering

In computer graphics, rendering is the process by which an abstract description of a scene is converted to an image. When the scene is complex, or when high-quality images or high frame rates are required, the rendering process becomes computationally demanding. To provide the necessary levels of performance, parallel computing techniques must be brought to bear. Today, parallel hardware is routinely used in graphics workstations, and numerous software-based rendering systems have been developed for general-purpose parallel architectures. This article provides an overview of the parallel rendering field, encompassing both hardware and software systems. The focus is on the underlying concepts and the issues which arise in the design of parallel renderers. We examine the different types of parallelism and how they can be applied in rendering applications. Concepts from parallel computing, such as data decomposition and load balancing, are considered in relation to the rendering problem. Our survey explores a number of practical considerations as well, including the choice of architectural platform, communication and memory requirements, and the problem of image assembly and display. We illustrate the discussion with numerous examples from the parallel rendering literature, representing most of the principal rendering methods currently used in computer graphics.