Fillets
            create a transition surface between two surfaces or sets of surfaces.
         
         Create a fillet surface
               between existing surfaces
            
            
               - Choose Surfaces > Surface Fillet   ❒. ❒.
- Set the construction type to Radius
                     or Chord. (See the section Choose the type of a fillet surface for
                  more information.)
               
- Check on Variable Fillets if
                  you want the radius or chordal distance of the fillet to vary along
                  its length.
               
- Select the first surface or set of surfaces,
                  then click Accept.
               
- Select the second surface or set of surfaces,
                  then click Accept.
                  
                     TipIf you use a pick-box
                        to select the second set of surfaces, it will not accidentally re-select
                        any surfaces from the first set.
                      
 An arrow appears
                     for each set of surfaces, indicating on which side of the surfaces
                     the fillet will be built. The software makes an educated guess about
                     where you intend to build the fillet, and orients the arrows accordingly. 
                   
- Click on an arrow to flip its direction,
                  or click on a surface to make the indicator appear at that location.
               
- Click Build.
                  The fillet is built on
                     the side of the surfaces indicated by the arrows.
                   
- For variable fillet surfaces, use the
                  manipulators to control the radius (or chordal distance) along the
                  length of the fillet. (See the sections Control the radius along the length of a variable fillet surface and Control the chordal distance along the length of a variable fillet surface for
                  more information.)
               
- Use the options in the Surface
                     Fillet Control window to control the shape of the fillet surface.
                  (See the section Manipulate fillet surface cross section and continuity for more
                  information.)
               
               NoteIf Surface Type is set to Multiple
                     surfaces and curves-on-surface are created at the edges
                  of the fillets (see Trim Type option) those curves-on-surface
                  are segmented to correspond to the multiple fillet surface boundaries.
                  To create the curves-on-surface as a single piece (for each surface),
                  set Surface Type to Single
                     surface
             
         Create a fillet surface
               between surface curves
            
            Freeform
                  blend lets you create a fillet between surface curves
               (surface boundaries, trim edges, Isoparametric curves or Curves-on-surface).
            
            In other words, you use
               surface curves on the two sets of surfaces to define the contact lines
               at the ends of the fillet.
            
            
               - Choose Surfaces > Multi-Surface Blend > Freeform Blend   ❒. ❒.
- Click surface curves on the first set
                  of surfaces to define the contact line.
                  The first set of curves is highlighted in purple. 
                     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.
                      
 
- Repeat for the second surface or set
                  of surfaces.
                  The
                     second set of curves is highlighted in yellow.
                   
- Press the Recalc button.
                  (This is not necessary
                     if Auto Recalc. is turned on in
                     the option window.)
                   
Adjust the alignment of
               the edges of the fillet/blend surfaces
            
            Use the options in the Flow
                  Control section to control how the blend surface(s) edges
               (in the V direction) meet up with the edges of the boundary surfaces.(
               See Surfaces > Multi-Surface Blend > Freeform Blend   ).
 ).
            
            You can adjust the alignment
               of the start, end, and (if more than one blend surface) interior edges.
            
         What if...?
            
               - The fillet surface will not build?
                  Try lowering the fillet
                     radius. Often the fillet does not build simply because there is not
                     enough room to create the radius set in the options.
                   
- I don’t want to trim the surfaces back?
                  The default is to automatically
                     trim the surfaces back to the new fillet surface. Use the Trim
                        Type option in the control window to have the fillet
                     tool only create curves-on-surface (but not trim), or turn trimming
                     off completely.