how to draw 2D line in the screen, no the in 3D screen

[aaaa]

how to draw 2D line in the screen, no the in 3D screen

[Jeff]

You can use an on-the-fly (http://docs.worldviz.com/vizard/#Creating_3D_models_procedurally--_the_basics.htm) line object:

import viz
viz.go()

#Add to viz.ORTHO and specify pixel coordinates
viz.startLayer(viz.LINES)
viz.vertex(100,400,0)
viz.vertex(600,400,0)
myLines = viz.endLayer(viz.ORTHO)