Surfacing > Creating Advanced Surface Features > Creating Boundary Blends > Setting Boundary Conditions
  
Setting Boundary Conditions
By setting boundary conditions, you can create blended surfaces that are tangent or curvature continuous to adjacent references (quilts or solid surfaces), are normal to a reference surface or plane, or have continuous curvature across the boundary with another surface.
Select the Add inner edge tangency check box to set the tangent inner edge condition for one or both directions of a blended surface. This condition applies only to surfaces with multi-segment boundaries. You can create a blended surface with patches that are tangent across inner edges. In some cases, when geometry is complex, dihedral angles at inner edges may deviate from zero.
Select the Add side curve influence check box to enable side-curve influence.