The offset of planar objects is done to make stacked, coplanar planar objects look like the plan-view equivalent, otherwise the overlapping objects will show all their lines (in hidden line), or with their fills overlapping and tearing (in Shaded rendering and possibly Renderworks.) If the objects are viewed face-on, you generally won't see the offset, but since it offsets based on the planar object's plane, if viewed edge-on the offset is most visible. It's actually happening in the iso view but because the offset is small, it's not apparent. For a workaround, do these need to be 2D polygons rather than 3D? The latter are not offset.