创建垂直于屏幕视图的矢量

该示例演示了如何使用SOLIDWORKS API绘制一条垂直于当前视图方向相对于屏幕的草图线。

该线将从屏幕中间的点开始，并且垂直于屏幕方向。这意味着在视图旋转之前，它将被渲染为点。

使用SOLIDWORKS API属性IModelView::Transform来提取当前视图方向相对于屏幕的变换矩阵。

{ width=320 height=208 }

Dim swApp As SldWorks.SldWorks
Dim swModel As SldWorks.ModelDoc2
Dim swMathUtils As SldWorks.MathUtility

Sub main()

    Set swApp = Application.SldWorks
    
    Set swMathUtils = swApp.GetMathUtility
    
    Set swModel = swApp.ActiveDoc
    
    If Not swModel Is Nothing Then
    
        Dim swModelView As SldWorks.modelView
        
        Set swModelView = swModel.ActiveView
        
        If Not swModelView Is Nothing Then
            
            Dim swNormVec As SldWorks.MathVector
            Dim swMidPt As SldWorks.MathPoint
            
            Set swNormVec = GetNormalVector(swModelView)
            Set swMidPt = GetMidPoint(swModelView)
            
            DrawVector swMidPt.ArrayData, swNormVec.ArrayData, 0.1
            
        Else
            MsgBox "活动模型中不包含视图"
        End If
        
    Else
        MsgBox "请打开3D模型"
    End If
    
End Sub

Function GetNormalVector(modelView As SldWorks.modelView) As SldWorks.MathVector
    
    Dim swScreenToModelViewTransform As SldWorks.MathTransform
    Set swScreenToModelViewTransform = modelView.Transform.Inverse()
    
    Dim dVec(2) As Double
    dVec(0) = 0: dVec(1) = 0: dVec(2) = 1
    
    Dim swNormVec As SldWorks.MathVector
    Set swNormVec = swMathUtils.CreateVector(dVec)
    
    Set swNormVec = swNormVec.MultiplyTransform(swScreenToModelViewTransform)
    
    Set GetNormalVector = swNormVec
    
End Function

Function GetMidPoint(modelView As SldWorks.modelView) As SldWorks.MathPoint
    
    Dim swScreenToModelViewTransform As SldWorks.MathTransform
    Set swScreenToModelViewTransform = modelView.Transform.Inverse()
    
    Dim dPt(2) As Double
    dPt(0) = modelView.FrameWidth / 2
    dPt(1) = modelView.FrameHeight / 2
    dPt(2) = 0
    
    Dim swMathPt As SldWorks.MathPoint
    Set swMathPt = swMathUtils.CreatePoint(dPt)
    
    Set swMathPt = swMathPt.MultiplyTransform(swScreenToModelViewTransform)
        
    Set GetMidPoint = swMathPt
    
End Function

Function DrawVector(startPt As Variant, dir As Variant, length As Double)
    
    swModel.ClearSelection2 True
    
    Dim swEndPt As SldWorks.MathPoint
    Dim swDirVec As SldWorks.MathVector
    
    Set swDirVec = swMathUtils.CreateVector(dir)
    Set swDirVec = swDirVec.Normalise()
    Set swDirVec = swDirVec.Scale(length)
    
    Set swEndPt = swMathUtils.CreatePoint(startPt)
    Set swEndPt = swEndPt.AddVector(swDirVec)
    
    Dim endPt As Variant
    endPt = swEndPt.ArrayData
    
    swModel.Insert3DSketch2 True
    swModel.SketchManager.AddToDB = True
    
    swModel.SketchManager.CreateLine startPt(0), startPt(1), startPt(2), endPt(0), endPt(1), endPt(2)
    
    swModel.SketchManager.AddToDB = False
    swModel.Insert3DSketch2 True
    
End Function