How to choose and set the options for the fillet tools based on the type of transition surface you need to build.

Choose Surfaces > Surface Fillet ❒ to show the fillet control window.

The Construction Type and Variable Fillets options let you choose how the tool creates the fillet surface:

• If Construction Type is set to Radius and Variable Fillets is turned off, the fillet maintains a constant radius along its entire length.
• If Construction Type is set to Chord and Variable Fillets is turned off, the fillet maintains a constant width (chordal distance) along its entire length. The Chord option is only available from the Advanced tab.

  

  NoteThe chordal distance is the length of the straight line that joins both sides of the fillet, at a given U parameter value.

  

  Constant Radius and Chord fillets.

• If Construction Type is set to Radius and Variable Fillets is turned on, you can set the radius at different points along the length of the fillet. See Control the radius along the length of a variable fillet surface for details.
• If Construction Type is set to Chord and Variable Fillets is turned on, you can set the chordal distance (or tangent length) at different points along the length of the fillet. See Control the chordal distance along the length of a variable fillet surface for details.

  

  Variable Radius and Chord fillets.

NoteTo create a fillet between surface curves (surface boundaries, trim edges, isoparametric curves, or curve-on-surface), choose Surfaces > Multi-Surface Blend > Freeform Blend .