效果：

代码：根据投影方向投影投影新曲线到面上 

  var pcb = workPart.Features.CreateProjectCurveBuilder(null);pcb.CurveFitData.Tolerance = 0.001;pcb.CurveFitData.AngleTolerance = 0.05;pcb.SectionToProject.DistanceTolerance = 0.001;pcb.SectionToProject.ChainingTolerance = 0.00095;pcb.SectionToProject.AngleTolerance = 0.05;pcb.SectionToProject.SetAllowedEntityTypes(NXOpen.Section.AllowTypes.CurvesAndPoints);pcb.SectionToProject.AllowSelfIntersection(true);var cdr = workPart.ScRuleFactory.CreateRuleBaseCurveDumb(new IBaseCurve[] { curve });pcb.SectionToProject.AddToSection(new SelectionIntentRule[] { cdr }, curve, null, null, new Point3d(), NXOpen.Section.Mode.Create, false);var plane = planeFace.CreatePlane();pcb.PlaneToProjectTo = plane;var nxobj = pcb.Commit();