ノンフォトリアリスティック·レンダリング

抄録

In this article, basics and examples of Non-Photorealistic Rendering (NPR) are introduced. NPR is one of the categories of computer graphics (CG). In contrast with the traditional photorealistic approach in CG, NPR is to create images with artificial enhancement like illustration or painting. There are three major objectives in NPR: simulation of traditional drawing techniques, visual information communication, and support for existing drawing techniques. As for implementations, NPR techniques can be classified from several points of view, such as a degree of user interaction, input data (2D image or 3D scene data), etc. From 2D images, NPR images can be created by several approaches such as stroke-based drawing, image decomposition, and image analogies. From 3D scene data, NPR techniques can be added on or replaced by traditional photorealistic rendering. Especially, it is effective to use line drawing techniques such as contour ⁄ edge drawing and hatching. For moving images, it is important to keep continuity between frames, especially for strokes. Shape deformation is also an important issue in NPR. In addition to shape exaggeration, multi viewpoint projection is used for deformation.