In the film and television industry, today's new cool effect eventually becomes just another tool in the toolbox. Image morphing techniques that were unique and exciting just a decade ago are now a standard part of children's shows. Once upon a time Gouraud shading, or even simple fill shading, was special. The field of real-time rendering in many ways recapitulates the evolution of computer graphics for still images. As processors get faster, algorithms that took minutes now take fractions of a second.
Graphics accelerators help perform operations that are widely used, such as filling triangles.
However, because the new factor of dedicated graphics hardware is added to the mix, new ways of performing old algorithms arise. In traditional computer graphics the lighting equation is resolved at each pixel in a single pass, either by Gouraud interpolation or per-pixel shading. Software real-time rendering engines use this approach. Because graphics accelerators provide some basic operations that are extremely fast, an elaborate lighting equation can broken into separate pieces which hardware can handle and combine in a few passes, in less time than a single software pass can complete. Special effects work for real-time rendering depends upon both classic computer graphics techniques and using available hardware acceleration to best effect.