Open CASCADE Technology  7.3.1.dev
Enumerations
GeomAbs_Shape.hxx File Reference

Enumerations

enum  GeomAbs_Shape {
  GeomAbs_C0, GeomAbs_G1, GeomAbs_C1, GeomAbs_G2,
  GeomAbs_C2, GeomAbs_C3, GeomAbs_CN
}
 Provides information about the continuity of a curve: More...
 

Enumeration Type Documentation

◆ GeomAbs_Shape

Provides information about the continuity of a curve:

  • C0: only geometric continuity.
  • G1: for each point on the curve, the tangent vectors "on the right" and "on the left" are collinear with the same orientation.
  • C1: continuity of the first derivative. The "C1" curve is also "G1" but, in addition, the tangent vectors " on the right" and "on the left" are equal.
  • G2: for each point on the curve, the normalized normal vectors "on the right" and "on the left" are equal.
  • C2: continuity of the second derivative.
  • C3: continuity of the third derivative.
  • CN: continuity of the N-th derivative, whatever is the value given for N (infinite order of continuity). Also provides information about the continuity of a surface:
  • C0: only geometric continuity.
  • C1: continuity of the first derivatives; any isoparametric (in U or V) of a surface "C1" is also "C1".
  • G2: for BSpline curves only; "on the right" and "on the left" of a knot the computation of the "main curvature radii" and the "main directions" (when they exist) gives the same result.
  • C2: continuity of the second derivative.
  • C3: continuity of the third derivative.
  • CN: continuity of any N-th derivative, whatever is the value given for N (infinite order of continuity). We may also say that a surface is "Ci" in u, and "Cj" in v to indicate the continuity of its derivatives up to the order i in the u parametric direction, and j in the v parametric direction.
Enumerator
GeomAbs_C0 
GeomAbs_G1 
GeomAbs_C1 
GeomAbs_G2 
GeomAbs_C2 
GeomAbs_C3 
GeomAbs_CN