Glossary - An Introduction to Computer Graphics for Artists - page 299

Computer Graphics A group of technologies used to produce art with a computer.
Although the term includes 2D graphics, its acronym, CG, is used almost exclu-
sively to describe 3D graphics.
Construction Error An error that is the result of the construction process.
Control Point A point that lies off a NURBS curve and directly at either end, to
defi ne the curvature of the curve.
Converge When two or more things draw near to each other.
Convert When one geometry type is translated into another; especially when
translating NURBS geometry into polygons or vice-versa.
Convincing A CG representation that, whether or not it is perfectly accurate, is a
credible representation of its target.
Coordinate The single-axis position of a given element. If plural, this can be a
complete description of the location of a point of group of points.
Credible Capable of being believed.
CPU Acronym for Central Processing Unit.
Cube A geometric primitive defi ned by eight equidistant points joined by straight
edges that form three right angles at each point. In CG, a cube may be a solid or
wire representation of this type of primitive.
Curvature Continuous Similar to tangency, but to a greater degree. Instead of
tangency being held by one control vertex on either side of the respective end-
points of two curves, there will be a minimum of two control points with match-
ing tangents on either side of the join.
Curve A collection of points whose coordinates are continuous functions of a sin-
gle independent variable.
Curve Detail See Curve Resolution .
Curve Resolution The number of line segments used to defi ne a curve. This is
expressed as the length of the curve divided by the number of segments used to
represent it.
Curve on surface A curve that has been projected onto a surface. Several methods
are available to do this, their chief difference being that some will project in a
perfectly straight line and others project based on normals or other surface
specifi c values. Straight-line projection often changes the length of the projected
curve, but surface-specifi c methods do not.
Cylinder A geometric primitive defi ned by height and radius.
Cylindrical Projection A type of projection where UV coordinates are projected
from a cylinder onto a usually cylindrical object.
Default A pre-defi ned value for a variable. Values of this type are used extensively
in computer applications for two reasons: to have a value where the application
requires one, prior to user input. To have a value that is understood to be common
or standard.
Delete To permanently remove from the current scene or fi le.
Depth Axis The Z-axis .
De-rez To reduce the number of polygons or other elements in a given object.
Design The act of graphically communicating desired characteristics of an object
or effect, and determining the appearance of it.