Do you mean any sort of line or a wireframe view of everything?
In any case I'd suggest using boxes rather than cylinders 'cause it's a lot less triangles.
Make a normal box mesh.. then do PositionMesh MyBox, 0, 0, 1 so the centre of the mesh is the start of the box.. then when you need to do a line, CopyEntity the box, ScaleEntity the copy to the length you need (and scale down the width/height to something small, 0.1 maybe), position it at the XYZ position of one end of your line, then rotate it to face the other end of the line (you can use a dummy object and PointEntity), and that should work.
In any case I'd suggest using boxes rather than cylinders 'cause it's a lot less triangles.
Make a normal box mesh.. then do PositionMesh MyBox, 0, 0, 1 so the centre of the mesh is the start of the box.. then when you need to do a line, CopyEntity the box, ScaleEntity the copy to the length you need (and scale down the width/height to something small, 0.1 maybe), position it at the XYZ position of one end of your line, then rotate it to face the other end of the line (you can use a dummy object and PointEntity), and that should work.