Shape oriented line drawing in real-time 3DCG

Abstract

In 2D animation and comics, the line quality of object outlines and contour lines are often varied to emphasize or exaggerate the shape of an object. One such technique is to vary the line thickness pending on the object shape. This technique is often used in sketching and drawing to give objects a greater sense of depth or dimension. When using toon rendering to simulate a 2D-esque effect in 3D animation, techniques that render object outlines of constant thickness, such as that proposed by [Saito and Takahashi 1990], are popular due to their ease of application. While existing methods such as that proposed by [Goodwin et al. 2007] allow for a certain level of dynamic line thickness through the use of shad-ing, they require long calculation times and are not suited for real time rendering.