About Defining Boundary Conditions
You can apply conditions to blended boundaries that constrain the new surface feature to existing surfaces or quilts. When you define boundary constraints, the system attempts to select default references based on the boundaries specified. You can accept the system defaults, or you can select your own references.
The boundary conditions are free (default), tangent, curvature, and normal. Consider the following information about boundary conditions and referenced entities:
• If Tangent or Curvature is specified and the boundary consists of a chain of one-sided edges or a curve from one-sided edges, the referenced entity is set by default, and the boundary automatically has the same reference surfaces as the one-sided edges.
• If Normal is specified and the boundary consists of a sketched curve, the referenced entity is set to sketching plane, and the boundary automatically has the same reference plane as the curve. If Normal is specified and the boundary consists of a chain of one-sided edges or a curve from one-sided edges, the default reference entity is used, and the boundary automatically has the same reference surfaces as the one-sided edges.
• For all other combinations of boundary conditions and boundaries, the referenced entity is set to the selected surface, and the system prompts you to select a reference surface or plane for each segment of the boundary.
Sensitive zones (free, tangent, curvature, and normal) are displayed on your model allowing you to identify conditions on each boundary. You can right-click the sensitive zone located next to each outside boundary (first and second directions) to access a shortcut menu with control boundary conditions.