Display.DisplayPipeline RhinoCommon

from David Rutten: link

Dim cd As New Rhino.Display.CustomDisplay(True)
cd.AddPoint(New Point3d(0,0,0))
cd.AddPoint(New Point3d(1,0,0), Color.DarkRed, PointStyle.Simple, 5)
cd.AddLine(New Line(New Point(0,0,0), New Point(1,0,0)), Color.DarkGreen, 4)
cd.AddVector(New Point3d(5,5,0), New Vector3d(0,0,10), Color.OrangeRed, True)

'from this point onwards the viewports will show the above geometry.

cd.Dispose()
'Once Dispose has been called the preview will be cleared. You can no longer use this instance of CustomDisplay from now on.