If the model includes intersecting geometry (such as an extrusion passing through a wall surface), Vasari does not create new edges along the lines of the intersection. As a result, Vasari may incorrectly remove hidden lines during export. If you export a view of the design with hidden lines turned on, you may see unexpected results when you open the view in another CAD application. See Hidden Line Visual Style.
To see all visible lines, create an opening in one surface before passing another surface through it, or join geometry to create an edge.
Intersected wall and extrusion in hidden line mode (no edges at the intersection of the surfaces)