By default, polygon elements are sent to the back of the draw order when they are drawn. If the draw order is modified, polygon elements can interfere with the visibility of other elements. This can be remedied using the AutoCAD Draw Order toolbar.

To access the AutoCAD Draw Order toolbar, right-click on the AutoCAD toolbar and click the Draw Order entry in the list of available toolbars.

By default, polygon elements are filled. You can make them unfilled (just borders visible) using the AutoCAD FILL command. After turning fill mode OFF, you must REGEN to redraw the polygons.