A vertex (plural vertices) in
computer graphics
Computer graphics deals with generating images with the aid of computers. Today, computer graphics is a core technology in digital photography, film, video games, cell phone and computer displays, and many specialized applications. A great de ...
is a data structure that describes certain attributes, like the position of a point in 2D or 3D
space
Space is the boundless three-dimensional extent in which objects and events have relative position and direction. In classical physics, physical space is often conceived in three linear dimensions, although modern physicists usually consider ...
, or multiple points on a surface.
Application to 3D models
3D models
In 3D computer graphics, 3D modeling is the process of developing a mathematical coordinate-based representation of any surface of an object (inanimate or living) in three dimensions via specialized software by manipulating edges, vertices, an ...
are most often represented as triangulated
polyhedra forming a
triangle mesh
In computer graphics, a triangle mesh is a type of polygon mesh. It comprises a set of triangles (typically in three dimensions) that are connected by their common edges or vertices.
Many graphics software packages and hardware devices can ...
. Non-triangular surfaces can be converted to an array of triangles through
tessellation
A tessellation or tiling is the covering of a surface, often a plane (mathematics), plane, using one or more geometric shapes, called ''tiles'', with no overlaps and no gaps. In mathematics, tessellation can be generalized to high-dimensional ...
. Attributes from the vertices are typically interpolated across mesh surfaces.
Vertex attributes
The vertices of triangles are associated not only with spatial position but also with other values used to
render the object correctly. Most attributes of a vertex represent vectors in the space to be
rendered. These vectors are typically 1 (''x''), 2 (''x, y''), or 3 (''x, y, z'') dimensional and can include a fourth
homogeneous coordinate
In mathematics, homogeneous coordinates or projective coordinates, introduced by August Ferdinand Möbius in his 1827 work , are a system of coordinates used in projective geometry, just as Cartesian coordinates are used in Euclidean geometry. Th ...
(''w''). These values are given meaning by a
material
Material is a substance or mixture of substances that constitutes an object. Materials can be pure or impure, living or non-living matter. Materials can be classified on the basis of their physical and chemical properties, or on their geologi ...
description. In
realtime rendering
Real-time computer graphics or real-time rendering is the sub-field of computer graphics focused on producing and analyzing images in real time. The term can refer to anything from rendering an application's graphical user interface (GUI) to ...
these properties are used by a
vertex shader or
vertex pipeline The function of the vertex pipeline in any GPU is to take geometry data (usually supplied as vector points), work with it if needed with either fixed function processes (earlier DirectX), or a vertex shader program (later DirectX), and create all of ...
.
Such attributes can include:
See also
For how vertices are processed on 3D graphics cards, see
shader.
References
{{DEFAULTSORT:Vertex computer graphics
Computer graphics