NURBS > Edit Control Points (available after NURBS > Fit Surfaces) modifies a NURBS surface by changing the position of individual NURBS control points. moves individual control points to a new location after the NURBS surface is fitted. You can move the control points in a variety of directions, such as the X, Y, or Z direction, or make them perpendicular to the surface. There are three Continuity Level options (Connectivity, Tangent or Curvature) which determine the relationship between the patches as control points are edited.
The parameters are:
Movement group - restricts the movement to a single direction when it is dragged by the mouse.
X Direction radio button - movement is restricted to the object’s X axis.
Y Direction radio button - movement is restricted to the object’s Y axis.
Z Direction radio button - movement is restricted to the object’s Z axis.
X/Y Plane radio button - movement is restricted to the object’s XY plane.
X/Z Plane radio button - movement is restricted to the object’s XZ plane.
Y/Z Plane radio button - movement is restricted to the object’s YZ plane.
Perpendicular radio button - movement is restricted to a direction that is perpendicular to the plane defined by surrounding points.
Continuity Level dropdown (Connectivity, Tangent, Curvature) - controls the degree to which the smoothness of the NURBS surface is maintained across patch lines. Note the control points appear in groups of one on the interior or patches, groups of three at the patch lines, and groups of nine at the patch corners.
Connectivity - only one selected NURBS control point is affected.
Tangent - if a point in a set of three or nine is dragged, the entire set of three or nine is affected.
Curvature - adjoining sets of three and nine are affected.
OK button - saves the new NURBS surface to the object and closes the dialog.
Cancel button - terminates the dialog without saving changes to the NURBS surface.