Non-photorealistic rendering

NPR is inspired by other artistic modes such as painting, drawing, technical illustration, and animated cartoons.

The first technical meeting dedicated to NPR was the ACM-sponsored Symposium on Non-Photorealistic Rendering and Animation[3](NPAR) in 2000.

With increased availability of programmable GPU's, shaders have allowed NPR effects to be applied to the rasterised image that is to be displayed to the screen.

Non-photorealistic renderings, such as exploded view diagrams, greatly assist in showing placement of parts in a complex system.

Its defining feature is the use of distinct shading colors rather than smooth gradients, producing a look reminiscent of comic books or animated films.

The output is a typically an artistic rendering of that input imagery (for example in a watercolor, painterly or sketched style) although some 2D NPR serves non-artistic purposes e.g. data visualization.

This automation enabled practical application of 2D NPR to video, for the first time in the living paintings of the movie What Dreams May Come (1998).

These algorithms underpin mobile apps capable of the same e.g. Prisma In addition to the above stylization methods, a related class of techniques in 2D NPR address the simulation of artistic media.

For photorealistic rendering styles, the emphasis is on accurate reproduction of light-and-shadow and the surface properties of the depicted objects, composition, or other more generic qualities.