Curvature-continuous checkbox is available in the bottom part of the General Parameters section in the Parameters window (independently of Edges, Vertices, Boundary and Trimming tabs) for all types of rounding. Enabling this checkbox implements curvature continuity (G2) between resulting blend surface and adjusting faces.

Using this option distorts Radius (for constant-radius and variable-radius rounding) or Offset 1, Offset 2 and Convexity coefficient (Rho) (for variable-elliptical rounding).

Affect of Curvature-continuous checkbox on different types of rounding: 1 и 2 - Cross-section shape of a blend surface in starting point of the edge 3 и 4 - Cross-section shape of a blend surface in ending point of the edge 1 и 3 - Curvature-continuous checkbox disabled 2 и 4 - Curvature-continuous checkbox enabled |

Constant-radius rounding |

Variable-radius rounding |

Variable-elliptical rounding, Convexity = 0.6 |

Variable-elliptical rounding, Convexity = 0.1 |