VB编程编辑AutoCAD样条曲线

编辑样条曲线的方法很多，可以通过对其进行拟合进行增加、移动和删除，提高拟合点的权重等操作，可以设置样条曲线的公差，可以提高样条曲线的等级总新定义样条曲线。

一下代码创建一条样条曲线，并改变公差，测试效果。

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 "样条曲线拟合公差为" & currfittolerance

splineobj.FitTolerance = 3

splineobj.Update

MsgBox "样条曲线拟合公差改变为" & splineobj.FitTolerance

End Sub

公差越小，各点的拟合情况越好，公差越大，生成的样条曲线月光滑，但各点的拟合情况越差。可以通过设置系统变量SPLFRAME使样条曲线的控制框和控制点显示出来。