Abstract: A graphics processing subsystem is programmed with shader programs that make calls to an abstract interface. One or more subshaders implementing the functions of the abstract interface can also be defined. The binding of interfaces to functions is resolved by a language runtime module that compiles the subshaders. As shader programs are compiled, the runtime module determines whether each method call is associated with an interface function. For each interface method call, the runtime module determines the appropriate implementation of the interface to be bound to the method call. Once the appropriate implementation is identified, the interface binding is created using string substitution or indirect addressing instructions. At the time of compilation, which may be during the execution of the rendering application, the desired combinations of subshaders are specified and compiled into a combined shader program, which can then be executed by the graphics processing subsystem.

Abstract: A physical camera is modeled to render an image in a computer graphics system. When given the manufacturer's specifications of the physical camera's lenses, including the dimensions and indices of refraction of its lenses, stops, and shutter characteristics, the location of the film surface relative to the lens system, and the orientation of the camera within the scene, the invention accurately and efficiently mimics the physical principles of image formation creating an image which approximates an image produced by the physical camera. The procedure comprises four main elements: (1) the geometric relationships between the lens system, object, and film plane are modeled by precise placement and movement of lens elements, (2) image geometry is computed by using principles of geometric optics, (3) an exit pupil is calculated in order to define a region for efficiently sampling rays, (4) the image irradiance, or exposure at a pixel, is computed according to radiometric principles.