Introduction to 3D Non-Photorealistic Rendering: Silhouettes and Outlines

In these notes, we survey some of the basic tools used for non-photorealistic rendering of 3D scenes. We will primarily focus on detecting outlines of object shape: silhouettes, boundaries, and creases. (Hatching and shading, which are also very important for communicating shape, are discussed elsewhere in the course notes.) The algorithms in this section can be divided into algorithms that operate in the image space (2D), and algorithms that operate in world space (3D).