Attribute VB_Name = "Module1"
      Option Explicit
      Dim gr0 As Graphic
      Dim gr1 As Graphic
      Dim gr2 As New Boolean3D
      Dim gr3 As Graphic
      Dim dr As Drawing
      
      Sub AddBoxAndSubtractBox()
      Set dr = Application.ActiveDrawing
      'draw "leg"
      Set gr0 = dr.Graphics.add(, "TCW40CUBE")
      gr0.Vertices.add 0, 0, 0 'start of box
      gr0.Vertices.add 10, 0, 0 'distance along X
      gr0.Vertices.add 0, 2, 2 'distance along Y
      gr0.Vertices.add 0, 0, 2 'distance along z
      'draw "mortise"
      Set gr1 = dr.Graphics.add(, "TCW40CUBE")
      gr1.Vertices.add 2, 0.5, 2
      gr1.Vertices.add 3.5, 0.5, 2
      gr1.Vertices.add 2, 1.5, 2
      gr1.Vertices.add 2, 0.5, 1
      'subtract mortise from leg
      Set gr3 = gr2.Subtract(gr0, gr1)
      'add new graphic to drawing graphics collection
      dr.Graphics.AddGraphic gr3
      'do some cleanup
      gr0.Delete
      gr1.Delete
      Set gr0 = Nothing
      Set gr1 = Nothing
      Set gr2 = Nothing
      Set gr3 = Nothing
      
      dr.ActiveView.Refresh
      Set dr = Nothing
      End Sub