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.
◦ Tangent—The blended surface is tangent to the reference surface along 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.
 | • 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. |
When the boundary conditions are set to Tangent, Curvature, or Normal, if required, select the Display drag handles check box to control the boundary stretch factor. Alternatively, you can type the stretch value in the Stretch value box. The default stretch factor is 1. The value of the stretch factor influences the direction of the surface.
4. Set boundary conditions for all the boundaries as required.
5. Define other optional feature elements or click 
OK to complete the feature.
OK to complete the feature.