2011

Table Of Contents
notification. Underlays cannot be bound to a drawing. See also external
reference (xref).
up direction A vector defining what direction is Up. By default this is the
positive Z axis (0,0,+1).
The up direction and the north direction are always constrained such that
they are perpendicular to each other.
user coordinate system (UCS) A user-defined coordinate system that defines
the orientation of the X, Y, and Z axes in 3D space. The UCS determines the
default placement of geometry in a drawing. See also world coordinate system
(WCS).
user parameter Named user-defined variable (real number or an expression)
that can be used in expressions for dimensional constraints or other user
parameters.
UVW The materials coordinate space. Used instead of XYZ because that is
usually reserved for the world coordinate system (WCS). Most material maps
are a 2D plane assigned to a 3D surface. The U, V, and W coordinates parallel
the relative directions of X, Y, and Z coordinates. If you look at a 2D map
image, U is the equivalent of X, and represents the horizontal direction of the
map. V is the equivalent of Y, and represents the vertical direction of the map.
W is the equivalent of Z and represents a direction perpendicular to the UV
plane of the map.
value node A specific type of action node that is used to handle requests for
user input and hold the recorded value that was captured during the recording
of an action macro.
value set In a dynamic block definition, a range or list of values specified for
a linear, polar, XY, or rotation parameter.
vector A mathematical object with precise direction and length but without
specific location.
vertex A location where edges or polyline segments meet.
vertical ribbon
The ribbon when it is oriented vertically, usually on the left or right of the
file window.
view A graphical representation of a model from a specific location (viewpoint)
in space. See also viewpoint and viewport. (3DORBIT, VPOINT, DVIEW, VIEW)
view category A named collection of views in a sheet set that is often
organized by function. See also subset.
2186 | Glossary