ABSTRACT
Research in real-time computer graphics focuses on trading speed of rendering for image quality but does not address the problem of frame rate stability, a critical component of the user experience. Common techniques offer “best effort” solutions to achieve interactive frame rates without any performance guarantee. This chapter introduces the concepts of control theory and demonstrates relevant techniques as mechanisms for achieving sustainable performance in real-time computer graphics rendering. The rendering process is modelled as the plant in control taxonomy. Its basic functionality is to process a stream of inputs such as 3D geometry and other rendering data to create a series of images in real time. The value of incorporating control principles in real-time rendering would be better appreciated by highlighting important concepts pertaining to control system design. Proportional, integral, derivative (PID) controllers have accumulated a long history since the industrial revolution and are known to operate in more than 80% of the world’s control systems.
