MAST 01/07
A Stylised Cartoon Renderer for Toon-Shading of 3D Character Models
Jung Shin
Department of Computer Science
University of Canterbury
Abstract
This thesis describes two new techniques for enhancing the rendering quality of cartoon characters
in toon-shading applications. The proposed methods can be used to improve the output
quality of current cel shaders. The first technique which uses 2D image-based algorithms, enhances
the silhouettes of the input geometry and reduces the computer generated artefacts. The
silhouettes are found by using the Sobel filter and reconstructed by Bezier curve fitting. The
intensity of the reconstructed silhouettes is then modified to create a stylised appearance. In the
second technique, a new hair model based on billboarded particles is introduced. This method
is found to be particularly useful for generating toon-like specular highlights for hair, which are
important in cartoon animations. The whole rendering framework is implemented in C++ using
the OpenGL API. OpenGL extensions and GPU programming are used to take the advantage
of the functionalities of currently available graphics hardware. The programming of graphics
hardware is done using Cg, a high level shader language.