How
            to create one or many transitional surface(s) between multiple continuous
            surface boundaries, by specifying any number of cross-sections (profile
            curves) between the primary surfaces.
         
         The primary surfaces’
            edges may be trimmed, untrimmed, curves on surface, or isoparms. 
         
         You can place any number
            of profile curves (cross-sections) at any point between the primary
            surfaces’ boundaries. Profiles can be any type of curves, including
            blend curves and surface boundaries.
         
         
            - Choose Surfaces > Multi-Surface Blend > Profile Blend   ❒ to open the option window. ❒ to open the option window.
- Select all the surface boundary curves.
               The first set of boundaries
                  is highlighted in purple, and the second set of boundaries is highlighted
                  in yellow.
                
                  NoteIf Chain Pick is
                     turned on in the option window, selecting the boundary of one surface
                     will also select all other boundaries that are tangent continuous
                     with it.
                   
 
- Press the Go button.
            
- Select all the profile curves that will
               define the transitional surface.
               The selected profile curves are highlighted
                  in white.
                After you select the first profile curve, a Recalc button
                  appears.
                
- Press the Recalc button
               when you’re finished selecting the profile curves.
               Blend surfaces are built between the primary
                  surfaces. 
                
- Set Surface
                  Type to Single surface in the option
               window, and click Recalc to compute a single
               blend surface if desired.
            
- Modify other parameters in the option
               window if necessary, then click Recalc to rebuild
               the surface (or turn on Auto Recalc. in
               the option window for the recalculation to happen automatically).
            
- Add or delete input curves by clicking
               on them, to further refine the transitional surface.
               
                  NoteSince the input curves
                     have construction history, modifying them also updates the transitional
                     surfaces.
                   
 
- Turn on Continuity Check in
               the option box to evaluate the continuity of the blend surface with
               the primary input surfaces. See the section Troubleshooting trimmed surfaces for
               more information.