• Position—A surface is said to be position constrained if the edge of the surface is constrained to the curve on that edge. You cannot drag the control points on this edge.

• Tangent Dependent—Surfaces are position constrained to a common boundary curve and are tangent to each other. In case of Tangent Dependent, the surface constraint follows the concept of leaders and followers. When a leader surface changes it shape, the follower surface adapts its shape to maintain tangency with the leader. An arrow pointing from the leader to the follower represents Tangent Dependent constraint.

• Tangent Symmetric—Surfaces have a common boundary and are tangent to each other. In case of Tangent Symmetric, a change that you make to one surface does not affect another surface. The surfaces do not follow the concept of leaders and followers. A line between the surfaces represents Tangent Symmetric constraint.

• Curvature Dependent—Surfaces are tangent continuous across the boundary and curvature continuous with each other. In case of Curvature Dependent, the surface constraint follows the concept of leaders and followers. When the shape of a leader surface is changed, the follower surface is changed to match the leader. Double arrows pointing from the leader to the follower represent a Curvature Dependent constraint.