By default, the AllowZoom property is True. If the AllowZoom property is False, the view is not magnified when the user rotates the mouse wheel. The control fires the Zoom event when the view is zoomed.  The Zoom property specifies the zooming factor. The KeyDown event notifies your application that the user presses a key.

For instance, the following sample zooms the view when the user presses the + or - keys from the numeric pad:

Private Sub Texture1_KeyDown(KeyCode As Integer, Shift As Integer)
    If (KeyCode = vbKeyAdd) Then
        Texture1.Zoom = Texture1.Zoom - 0.01
    Else
        If (KeyCode = vbKeySubtract) Then
            Texture1.Zoom = Texture1.Zoom + 0.01
        End If
    End If
End Sub