3D model
From Wikipedia, the free encyclopedia
In 3D computer graphics, a 3D model is a mathematical representation of a three-dimensional object. It can be displayed as a two-dimensional image through a process called 3D rendering or used in a computer simulation of physical phenomena.
3D models are most often created with special software applications called 3D modelers. Being a collection of data (points and other information), 3D models can be created by hand or algorithmically (procedural modeling). Though they most often exist virtually (on a computer or a file on disk), even a description of such a model on paper can be considered a 3D model.
3D models are widely used anywhere 3D graphics are used. Actually, their use predates the widespread use of 3D graphics on personal computers. Many computer games used pre-rendered images of 3D models as sprites before computers could render them in real-time.
Today, 3D models are used in a wide variety of fields. The medical industry uses detailed models of organs. The movie industry uses them as characters and objects for animated and real-life motion pictures. The video game industry uses them as assets for computer and video games. The science sector uses them as highly detailed models of chemical compounds. The architecture industry uses them to demonstrate proposed buildings and landscapes. The engineering community uses them as designs of new devices, vehicles and structures as well as a host of other uses. In recent decades the earth science community has started to construct 3D geological models as a standard practice.
A 3D model by itself is not visual. It can be rendered as a simple wireframe at varying levels of detail, or shaded in a variety of ways. Many 3D models, however, are covered in a covering called a texture (the process of aligning the texture to coordinates on the 3D model is called texture mapping). A texture is nothing more than a graphic image, but gives the model more detail and makes it look more realistic. A 3D model of a person, for example, looks more realistic with a texture of skin and clothes, than a simple monochromatic model or wireframe of the same model.
Other effects, beyond texturing, can be done to 3D models to add to their realism. For example, the surface normals can be tweaked to effect how they are lit, certain surfaces can have bump mapping applied and any other number of 3D rendering tricks can be applied.
3D models are often animated for some uses. For example, 3D model are heavily animated for use in feature films and computer and video games. They can be animated from within the 3D modeler that created them or externally. Often extra data is added to the model to make it easier to animate. For example, some 3D models of humans and animals have entire bone systems so they will look realistic when they move and can be manipulated via joints and bones.
