[求助]如何将一系列的点（X i， Yi)拟合并连接成一条光滑的线？

heimj

有一系列的点（X i， Yi) (i=1 ,2 .........N)，我用line连接每一点，成了N-1条线，用spline 连接，每次只能连接3个点，成了多线段，

请问：如何连接成一条光滑的曲线？（用vb在CAD中实现）

谢谢！！！

fjfhgdwfn

Public WithEvents PLine As AcadLWPolyline    ' Use with Modified Event Example

Sub Example_Modified()
     ' This example creates a lightweight polyline in model space and
     ' references the PolyLine using the public variable (PLine) which
     ' is set up to intercept Modified events.
     '
     ' This example then modifies the new object, triggering the code
     ' in the Modified event.
    
    Dim points(0 To 9) As Double
    
    ' Define the 2D polyline points
    points(0) = 1: points(1) = 1
    points(2) = 1: points(3) = 2
    points(4) = 2: points(5) = 2
    points(6) = 3: points(7) = 2
    points(8) = 4: points(9) = 4
        
    ' Create a lightweight Polyline object in model space
    '
    ' * Note: We are returning the new PolyLine object into a Module
    ' level variable.  This allows us to intercept events associated
    ' with that particular object.
    Set PLine = ThisDrawing.ModelSpace.AddLightWeightPolyline(points)
    
    ThisDrawing.Application.ZoomAll
    
    ' Modify object to trigger event.
    '
    ' * Note: The event code for the PolyLine modification will be triggered
    ' before we move forward and refresh the view, so the line will not
    ' appear blue when the event message box is displayed.
    Dim color As AcadAcCmColor
    Set color = AcadApplication.GetInterfaceObject("AutoCAD.AcCmColor.16")
    Call color.SetRGB(80, 100, 244)
    PLine.TrueColor = color

    ThisDrawing.Regen acAllViewports
    
End Sub

Private Sub PLine_Modified(ByVal pObject As AutoCAD.IAcadObject)
    ' This example intercepts an object's Modified event.
    '
    ' This event is triggered when an object supporting this event is modified.
    '
    ' To trigger this code: Modify an object connected to this event
    ' * Note: By connected, we mean the object set up to intercept events using
    ' the VBA WithEvents statement

    ' Use the "pObject" variable to determine which object was modified
    MsgBox "You just modified an object with an ID of: " & pObject.ObjectID
    
End Sub

heimj

谢谢！

我试试看。

heimj

连接的是多边形啊，我要的是曲线，不知道能否实现？

heimj

请有知道的高手赐教,谢谢!!!

licong

RetVal = object.AddSpline(PointsArray, StartTangent, EndTangent)

用这个行不行呀

laoliu09

样条曲线！

licong

嗯,样条曲线可以!主要是StartTangent、 EndTangent这两个参数的设置，在这两个参数中的三个元素是不是第一个是对于X轴的tangent,第二个参数是关于Y轴的tangent,第三个参数是关于Z轴的tangent.

我做了一个桥型曲线，效果还可以

Sub drawspline()
Dim x As AcadSpline
Dim pt(1 To 75) As Double
Dim xlapp As Excel.Application
Dim xlbook As Workbook
Dim xlsheet As Worksheet
Dim startangent(0 To 2) As Double
Dim endtangent(0 To 2) As Double
startangent(0) = 0
startangent(1) = 0
startangent(2) = 0
endtangent(0) = 0
endtangent(1) = 0
endtangent(2) = 0
Set xlsApp = New Excel.Application
Set xlbook = xlsApp.Workbooks.Open("F:\CAD练习\book1.xls")
Set xlsheet = xlbook.Worksheets("sheet1")
For i = 1 To 75 Step 3
   With xlsheet
   pt(i) = .Cells(i, 1)
   pt(i + 1) = .Cells(i, 2)
   pt(i + 2) = .Cells(i, 3)
   End With
  
Next i
Set x = ThisDrawing.ModelSpace.AddSpline(pt, startangent, endtangent)

End Sub

heimj

谢谢你们！

我试试看。

heimj

我刚试过了，是一条光滑的曲线，但在所有点画完后，又与原点连接了，这是怎么回事？请问怎样解决？

谢谢！！！