Selecting a Feature Based on Number of Sides

Best practice guidelines recommend you consider the number of sides when deciding the type of feature to create, one of a fill feature, boundary, loft, or sweep.

  • For two or four-sided features, use boundary, loft, or sweep.
  • For features with three, five, or more sides, use fill.


A common vertex shared by two or more profiles is called a degenerate point. The internal surface flow (UV lines) converge to a single point. A degenerate point can result in downstream problems if you offset or shell the face or apply a radius to its edge.

Flow Lines in a Three-Sided Loft Versus a Fill