OpenGL Programming Guide: The Official Guide to Learning OpenGL, Version 4.3, Eighth Edition

Sources of Aliasing

Aliasing can be generally explained by sampling theory, while specific forms of aliasing can be explained more concretely by specific situations. We will tie together both approaches, and this will become clearer as the forms are discussed. Most generally, from a sampling theory perspective, a graphics image is made from point samples of the scene. If patterns in the scene vary at a high spatial frequency with respect to the samples, the samples can’t accurately reproduce the scene; they are hit and miss on interesting features. A periodic pattern needs to be sampled at at least twice the frequency of the pattern itself; otherwise the image will break down when it has a pattern changing faster than every two samples, causing ...