Vertex (computer graphics)

A vertex (plural vertices) in computer graphics is a data structure that describes certain attributes, like the position of a point in 2D or 3D space, or multiple points on a surface.

Application to 3D models

3D models are most often represented as triangulated polyhedra forming a triangle mesh. Non-triangular surfaces can be converted to an array of triangles through tessellation

. 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

vertex shader or vertex pipeline

.

Such attributes can include:

Position

2D or 3D coordinates representing a position in space

Color

Typically diffuse or specular

precomputed lighting

information.

Reflectance

of the surface at the vertex, e.g.

specular exponent

, metallicity, fresnel values.

Texture coordinates

Also known as

UV coordinates, these control the texture mapping

of the surface, possibly for multiple layers.

normal vectors

These define an approximated curved surface at the location of the vertex, used for lighting calculations (such as Phong shading), normal mapping, or displacement mapping, and to control subdivision.

tangent vectors

These define an approximated curved surface at the location of the vertex, used for lighting calculations (such as Phong shading), normal mapping, or displacement mapping, and to control subdivision.

Blend weights

Bone weights

Weighting for assignment to bones to control deformation in skeletal animation.

Blend shapes

Multiple position vectors may be specified to be blended over time, especially for

facial animation

.

References

Application to 3D models

Vertex attributes

See also

References