編輯樣條曲線的方法很多，可以通過對其進行擬合進行增加、移動和刪除，提高擬合點的權重等操作，可以設置樣條曲線的公差，可以提高樣條曲線的等級總新定義樣條曲線。

一下代碼創建一條樣條曲線，并改變公差，測試效果。

Private Sub Command1_Click()
    acadapp.ActiveDocument.SetVariable "SPLFRAME", 0
    Dim splineobj As AcadSpline
    Dim noofpoints As Integer
    Dim starttan(0 To 2) As Double
    Dim endtan(0 To 2) As Double
    Dim fitpoints(0 To 8) As Double
    noofpoints = 3
    starttan(0) = 0.5: starttan(1) = 0.5: starttan(2) = 0
    endtan(0) = 0.5: endtan(1) = 0.5: endtan(2) = 0
    fitpoints(0) = 1: fitpoints(1) = 1: fitpoints(2) = 0
    fitpoints(3) = 5: fitpoints(4) = 5: fitpoints(5) = 0
    fitpoints(6) = 10: fitpoints(7) = 0: fitpoints(8) = 0
    Set splineobj = acadapp.ActiveDocument.ModelSpace.AddSpline(fitpoints, starttan, endtan)
    ZoomExtents
    splineobj.Update
    Dim currfittolerance As Double
    currfittolerance = splineobj.FitTolerance
    MsgBox "樣條曲線擬合公差為" & currfittolerance
    splineobj.FitTolerance = 3
    splineobj.Update
    MsgBox "樣條曲線擬合公差改變為" & splineobj.FitTolerance
End Sub

公差越小，各點的擬合情況越好，公差越大，生成的樣條曲線月光滑，但各點的擬合情況越差。可以通過設置系統變量SPLFRAME使樣條曲線的控制框和控制點顯示出來。