Digital rendering is a process that involves using a software program to generate an image from a previously created model. The model used in digital rendering is a description of a three dimensional object, made using a strictly defined data structure or language. The description used with this type of rendering includes viewpoint, geometry, lighting, and texture information.
The image created through digital rendering is referred to as a digital image or a raster graphics image. This digital image is the last major step before creating the final appearance of models used in animation. This animation is used in movies, video games, computer games, and simulators, and for special effects on television. Each of these uses for digital rendering utilizes different features and techniques in order to achieve the desired outcome.
Software for this process is available in a wide range of capabilities. Some rendering software is integrated into much larger animation or modeling packages, while other software is designed as a stand-alone product. Regardless of the exact capabilities and uses of the digital rendering software, all packages are carefully engineered programs that require integrating a number of disciplines, including mathematics, light physics, software development, and visual perception.
When digital rendering is used in the creation of three dimensional graphics, the process is often quite slow and may be referred to as pre-rendering or real time rendering. Pre-rendering is typically used when creating animated movies, while real time rendering is used for creating three dimensional video games that utilize graphics cards with three dimensional hardware accelerators.
The image created by this process is identified through a variety of visible features that may be altered as necessary. These features include:
Shading – brightness and color
Bump-mapping – simulated small scale bumpiness
Texture-mapping – method for applying detail
Reflection – mirror-like image
Motion blur – the effect of blurriness from a fast moving object
Fogging – the way light dims when it passes through air or atmosphere that is not clear
Transparency – transmission of light through solid objects
Translucency – scattered transmission of light through solid objects
Refraction – bending of light used with transparency
Shadows – effect created by obstructing light
Soft shadows – effect of partially obstructed light
Depth of field – blurry appearance of object because it is too far forward or behind to be in focus