nonphotorealistic

Nonphotorealistic refers to art and rendering approaches that do not attempt to reproduce the appearance of the real world. In computer graphics, nonphotorealistic rendering (NPR) describes methods that deliberately avoid photorealistic shading and lighting in favor of stylization, abstraction, or expressive technique. NPR aims to communicate information, mood, or artistic intent rather than exact physical realism.

NPR encompasses a wide range of styles. Painterly rendering imitates traditional painting with visible brush strokes and textures. Toon shading (cel shading) creates flat color regions with clear, bold edges to resemble cartoons. Ink-and-wash and watercolor-inspired approaches simulate traditional media. Line art and sketch rendering emphasize contours, cross-hatching, and gestural marks. Stroke-based and stippling techniques construct images from discrete marks or lines, enabling varied textures and rhythms. These techniques can be applied to either 2D images or 3D scenes.

Applications of NPR include video games, animated films, architectural visualization, medical illustration, and data visualization, where emphasis on readability, communication, or artistic identity may trump photographic likeness. NPR workflows often provide artists with control over style and expression, while maintaining practical considerations such as rendering performance and consistency across scenes.

Overview of development in NPR highlights the balance between aesthetic quality and perceptual clarity, as well as the integration of user-driven style parameters. NPR remains a prominent alternative to photorealistic rendering for projects seeking distinctive visual language.

See also: nonphotorealistic rendering, stylization, toon shading, painterly rendering.