Rendering (computer graphics)

Rendering is the process of generating an image from input data such as 3D models. The word "rendering" (in one of its senses) originally meant the task performed by an artist when depicting a real or imaginary thing (the finished artwork is also called a "rendering"). Today, to "render" commonly means to use a computer to generate an image from a precise specification, often created by an artist (or multiple artists) via interactive 3D modeling software. Types of images rendered include both still images and frames for films and video games. In a computer graphics context, in standard usage, the word "rendering" by itself means rendering 3D scenes, but it is sometimes used with a broader meaning. A modifier such as "2D" or "3D" is used when there is potential ambiguity (e.g. 3D rendering). A software application or component that performs rendering is called a rendering engine, render engine, rendering system, graphics engine, or simply a renderer. A distinction is made between real-time rendering, in which images are generated and displayed immediately (ideally fast enough to give the impression of motion or animation), and offline rendering (sometimes called pre-rendering) in which images or film frames, are generated for later viewing. Offline rendering can use a slower and higher-quality renderer. Interactive applications such as games must primarily use real-time rendering, although they may incorporate pre-rendered content. Rendering produces images of scenes or objects defined using coordinates in 3D space, seen from a particular viewpoint. It uses knowledge and ideas from optics, the study of visual perception, mathematics, and software engineering, and it has applications such as video games, simulators, visual effects for films and television, design visualization, and medical diagnosis. Realistic rendering requires modeling the propagation of light in an environment, e.g. by applying the rendering equation. Real-time rendering uses high-performance...