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...

◆ GeomAbs_Shape

 enum 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