Real-time nonphotorealistic rendering
Lee Markosian, Michael A. Kowalski, Daniel F. Goldstein, Samuel J. Trychin, John F. Hughes, Lubomir Bourdev · 1997
Nonphotorealistic rendering (NPR) can help make comprehensible but simple pictures of complicated objects by employing an econ-omy of line. But current nonphotorealistic rendering is primarily a batch process. This paper presents a real-time nonphotorealistic renderer that deliberately trades accuracy and detail for speed. Our renderer uses a method for determining visible lines and surfaces which is a modification of Appel’s hidden-line algorithm, with im-provements which are based on the topology of singular maps of a surface into the plane. The method we describe for determining visibility has the potential to be used in any NPR system that re-quires a description of visible lines or surfaces in the scene. The major contribution of this paper is thus to describe a tool which can significantly improve the performance of these systems. We demon-strate the system with several nonphotorealistic rendering styles, all of which operate on complex models at interactive frame rates.