Physically Based Rendering, 2nd Edition

Chapter Seven Sampling and Reconstruction

Although the final output of a renderer like pbrt is a two-dimensional grid of colored pixels, incident radiance is actually a continuous function defined over the film plane. The manner in which the discrete pixel values are computed from this continuous function can noticeably affect the quality of the final image generated by the renderer; if this process is not performed carefully, artifacts will be present. Fortunately, a relatively small amount of additional computation to this end can substantially improve the quality of the rendered images.

This chapter introduces sampling theory—the theory of taking discrete sample values from functions defined over continuous domains and then using those samples ...