指定した地点の TIN サーフェス高を取得

Private Sub UIToolControl1_MouseDown(ByVal button As Long, ByVal shift As Long, ByVal x As Long, ByVal y As Long)

    Dim pMxApplication As IMxApplication
    Set pMxApplication = Application
    
    Dim pMxDocument As IMxDocument
    Set pMxDocument = ThisDocument
    
    Dim pTinLayer As ITinLayer
    Set pTinLayer = pMxDocument.FocusMap.Layer(0)
    
    'GetElevation
    Dim pTinSurface As ITinSurface
    Set pTinSurface = pTinLayer.Dataset
    
    Dim pPoint As IPoint
    Set pPoint = pMxApplication.Display.DisplayTransformation.ToMapPoint(x, y)
    
    Debug.Print pTinSurface.GetElevation(pPoint)
    
    'InterpolateZ
    Dim pTinSurface3 As ITinSurface3
    Set pTinSurface3 = pTinLayer.Dataset
    pTinSurface3.InterpolationMethod = esriLinearInterpolation
    Debug.Print pTinSurface3.InterpolateZ(pPoint.x, pPoint.y)

End Sub