In two-dimensional space, such as a drawing, every object has two coordinates (X and Y) that define the horizontal and vertical space the object occupies, and its location. When you move to three-dimensional (or 3D) space, another coordinate (Z) represents an object’s depth. Since 3D animation works within the two-dimensional interface of a computer, using the XYZ coordinate system provides the illusion of three dimensions.
All 3D objects consist of groups of values (X, Y, Z) in 3D space that define the object’s orientation. These XYZ coordinates also let you situate an object in 3D space.
Most 3D software represents the X, Y, and Z axes using perpendicular arrows that intersect at the center (origin) of an object . The origin is the reference point for the object. These arrows are typically color-coded as red (X), green (Y), and blue (Z).
Y defines the up and down axis, X the left and right axis, and Z the forward and back axis.
In the previous figure, the X coordinate defines the horizontal space in the scene, while Y defines the vertical space, and Z adds the third dimension by defining the depth to and away from the origin.
Every object in three-dimensional space can move horizontally (left and right), vertically (up and down), and forward and backward.