Boundary Condition Influence
Once a boundary condition has been applied you can adjust the influence into the surface of that condition.
Control Points
If your boundaries are created from a chain of edges (arcs or splines) then the resultant surface has to have multiple patches – edges propagating from each chain junction – the Control Points.
If the boundary pair have differing numbers of Control Points then the system needs to split the chain with fewer element to accommodate the chain with more elements, sometimes the results are not appropriate.
Use the Control Points tab to decide connections between control points.
Inner Edge Tangency
Many surfaces will have multiple patches adjacent to a single boundary. If a patch edge connects to the surface boundary a patch will be formed in that surface and the inner patch edge will by default be tangent to the external patch edge.
This condition can be relieved if needed
In this video, control points are also manipulated to fine tune the surface.
Sketcher – Convert Arc Chain to Splines
Sometimes useful where you need the control of straight lines and arcs but want to reduce the number of patches and maybe improve the boundary transition.
In Sketcher > Ctrl select the appropriate curves > Operations > Convert To > Spline
Set Boundary influences
In a one-directional blended surface, for boundary conditions specified as tangent or curvature, Creo makes the side edges of the blended surface tangent to the side edges of the references.
CADCAM Resources 