About Surface Connections
Surface connections, like curve connections, are based on the concepts of parents and children. A parent surface does not change its shape, while a child surface changes its shape to meet the parent. Surface connection arrows point from the parent surface to the child surface. You can use the Surface tool or the Surface Connection tool to create the following connections:
G0 - Position—The surfaces share a common boundary, but no shared tangent or curvature exists across the boundary.
G1 - Tangent—Two surfaces are tangent to each other at every point along a common boundary.
G2 - Curvature—The surfaces are tangent continuous across the boundary, and they share curvature along the common boundary.
G3 - Acceleration—The surfaces are tangent continuous across the boundary, they share curvature along the common boundary, and the amount of change in curvature is the same.
Normal—The boundary curve that supports the connection is planar, and all the cross-boundary curves have curve tangents normal to the plane of this boundary.
Flip Direction—For a loft surface that has a boundary curve whose points and endpoint tangents are coplanar, a Normal connection type is available. For these Normal connections, Flip Direction flips the normal direction of the connection to the other side of the curve, and therefore flips the loft surface to the other side of the boundary curve.
Draft—All cross-boundary curves have draft curve connections at the same angle to the reference plane or a surface relative to the shared boundary.
Controlling Surface Connections in Composite Surfaces
You can control connections across composite boundaries but not connections within the composite surfaces. The continuity within composite surfaces is maximum if the associated boundary curves have curvature continuity, tangent continuity, or position continuity. Connections along a composite boundary of a surface function as a group and are displayed in a different color. For example, inverting the parent-child relationship at one of the surface connections inverts all others along the boundary.