2011

solid primitive A basic solid form. Solid primitives include: box, wedge, cone, cylinder,
sphere, torus, and pyramid.
spatial index A list that organizes objects based on their location in space. A spatial index
is used to locate what portion of the drawing is read when you partially open a drawing.
Saving a spatial index with a drawing also enhances performance when working with external
references. The INDEXCTL system variable controls whether layer and spatial indexes are
saved with a drawing.
specular reflection The light in a narrow cone where the angle of the incoming beam equals
the angle of the reflected beam.
spline-fit Uses the vertices of the selected polyline as the control points, or frame, of a curve
approximating a B-spline. This curve, called a spline-fit polyline, passes through the first
and last control points unless the original polyline was closed.
split face A mesh face that has been subdivided along a specified vector.
STB file For plot style table file. Contains plot styles and their characteristics.
sub-prompt A command prompt that instructs for a form of input to complete a command
or alter a property.
subdivision A division, or tessellation in a mesh object. As a mesh object is smoothed, the
number of subdivisions increases.
subobject A part of a composite object.
surface A surface is a 3D object that is a thin shell. Surfaces do not have mass or volume as
3D solids do. There are 3 types of surfaces: analytic, generic, and NURBS.
surface associativity See associative surfaces
surface normal Positive direction perpendicular to the surface of an object.
swept solid/surface A solid or surface created in the shape of the specified profile (the swept
object) swept along the specified path. (SWEEP)
symbol A representation of an item commonly used in drawings. Symbols are inserted in
drawings as blocks.
symbol table See definition table and block definition table.
system variable A name that is recognized as a mode, size, or limit. Read-only system
variables, such as DWGNAME, cannot be modified directly by the user.
table A rectangular array of cells that contain annotation, primarily text but also blocks. In
the AEC industry, tables are often referred to as “schedules” and contain information about
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