To Define Boundary Conditions
1. Click > 
Boundary Blend. The Boundary Blend tab opens.
Boundary Blend. The Boundary Blend tab opens.2. Click the Constraints tab. The Boundary column lists all surface boundaries.
3. In the Condition column, click the box adjacent to the boundary for which you want to set the boundary condition, and select one of the following boundary conditions from the Condition list box:
◦ 
Free—No tangency conditions are set along the boundary.
Free—No tangency conditions are set along the boundary.◦ 
Tangent—The blended surface is tangent to the reference surface along the boundary.
Tangent—The blended surface is tangent to the reference surface along the boundary.◦ 
Curvature—The blended surface has curvature continuity across the boundary.
Curvature—The blended surface has curvature continuity across the boundary.◦ 
Normal—The blended surface is normal to the reference surface or datum plane.
Normal—The blended surface is normal to the reference surface or datum plane. | • For conditions other than Free, select reference surfaces. Selecting the boundary displays the surface referenced for the boundary conditions in the surfaces list. • Alternatively, you can right-click sensitive zones located next to each outside boundary (first and second directions) to access and control boundary conditions. |
4. Optionally, to define the boundary stretch value, do one of these things:
◦ Next to Stretch value, type a value. The default stretch value is 1. To change the surface connection direction, enter a negative stretch value.
◦ Select the Show stretch handles check box, and then drag the handle. To change the surface connection direction, drag the stretch handle to the other direction.
Available when the boundary conditions are set to Tangent, Curvature, or Normal.
5. Set boundary conditions for all the boundaries as required.
6. Define other optional feature elements or click 
OK to complete the feature.
OK to complete the feature.