The Geometric primitive package contains all the geometric primitives and supporting data types used in describing their boundaries. A geometric primitive is a geometric object that is not decomposed further into other primitives in the system. This includes curves and surfaces, even though they are composed of curve segments and surface patches, respectively. Those curve segments and surface patches cannot exist outside the context of a primitive.
NOTE: Most geometric primitives are decomposable infinitely many times. Adding a centre point to a line may split that line into two separate lines. A new curve drawn across a surface may divide that surface into two parts, each of which is a surface. This is the reason that the normal definition of primitive as "non-decomposable" is not plausible in a geometry model - the only non-decomposable object in geometry is a point.
Any geometric object that is used to describe a feature is a collection of
geometric primitives. A collection of geometric primitives may or may not be a geometric complex.
Geometric complexes have additional properties such as closure by boundary operations and mutually
exclusive component parts.
Complex share most semantics, in the meaning of operations and
attributes. There is an exception in that a
Primitive shall not
contain its boundary (except in the trivial case of
the boundary is empty), while a
Complex shall contain its boundary
in all cases.
Interface Summary Interface Description BearingRepresents direction in the coordinate reference system. CurveCurve with a positive orientation. CurveBoundaryThe boundary of curves. CurveSegmentDefines a homogeneous segment of a curve. OrientableCurveA curve and an orientation inherited from
OrientablePrimitivePrimitives that can be mirrored into new geometric objects in terms of their internal local coordinate systems (manifold charts). OrientableSurfaceA surface and an orientation inherited from
PointBasic data type for a geometric object consisting of one and only one point. PrimitiveAbstract root class of the geometric primitives. PrimitiveBoundaryThe boundary of primitive objects. PrimitiveFactoryA factory of primitive geometric objects. RingRepresent a single connected component of a surface boundary. ShellRepresents a single connected component of a solid boundary. SolidBasis for 3-dimensional geometry. SolidBoundaryThe boundary of solids. SurfaceSurface with a positive orientation. SurfaceBoundaryThe boundary of surfaces. SurfacePatchDefines a homogeneous portion of a surface.
Class Summary Class Description CurveInterpolationList of codes that may be used to identify the interpolation mechanisms. SurfaceInterpolationList of codes that may be used to identify the interpolation mechanisms.