Non-Photorealistic Computer Graphics Library

Automatic Rendering of 3D Animal Models in Chinese Painting Style

Author(s): Jun-Wei Yeh.
Master Thesis: National Taiwan University, 2002.
[BibTeX]

Abstract:
A set of algorithms is proposed in this paper to automatically transform 3D animal models to Chinese painting style. Inspired by the real painting process in Chinese painting of animals, we divide the whole rendering process into two parts: borderline stroke making and interior shading. In borderline stroke making process we first find 3D model silhouettes in real-time depending on the viewing direction of a user. After retrieving silhouette information from all model edges, a stroke linking mechanism is applied to link these independent edges into a long stroke. Finally we grow a plain thin silhouette line to a stylus stroke with various widths at each control point and a 2D brush model is combined with it to simulate a Chinese painting stroke. In the interior shading pipeline, three stages are used to convert a Gouraud-shaded image to a Chinese painting style image: color quantization, ink diffusion and box filtering. The color quantization stage quantizes all pixels in an image into four color levels and each level represents a color layer in a Chinese painting. The ink diffusion stage is used to transfer ink and water among different levels and to grow areas in an irregular way. The box filtering stage blurs sharp borders among different levels to embellish the appearance of final interior shading image. In addition to automatic rendering, an interactive Chinese painting system which is equipped with friendly input devices can be also combined to generate more artistic Chinese painting images manually.