- group a3d_crv
Creates and accesses entities that represent geometric curves.
Geometric curves (A3DCrvBase) are a mandatory part of the topology construct in an A3DTopoBody entity. Do not confuse an A3DCrvBase entity with an A3DRiCurve entity. The latter is a particular representation item that has an A3DTopoSingleWireBody as its topology entry point.
All curves are defined as described in these steps:
Define the canonical form of the whole curve.
Define the actual parameterization and the portion of curve (trimming information) (A3DParameterizationData).
Define the orientation and scaling of the curve using a Cartesian transformation. The transformation cannot specify mirror or non-uniform scaling transformations (see A3DMiscCartesianTransformationData).
Here are definitions for terms that apply to curves.
Curve is a mathematical description for a whole curve.
Arc is a portion of a curve corresponding to an interval.