NURBS > Modify Surface Tension allows adjustment of the surface tension that was specified in NURBS > Fit Surfaces.
Surface Tension decimal field - see NURBS > Fit Surfaces.
OK button - saves the NURBS surface to the Shape object in the Model Manager and closes the dialog.
Cancel button - terminates the dialog without saving the NURBS surface.
Apply button - generates a preview based on the Control Points and Tension values.