Notes on Hidden Line RenderingKeyCreator \ View \ Render \ Notes-on-Hidden-Line-Rendering
The following rules apply to hidden line rendering (HLR) modes for solid objects:
The actual entities are not modified to support the rendering. The modifications are made only in the display. As a result, dimensions remain associative, and different renderings can be executed simultaneously in multiple viewports. In some cases, for instance, when dealing with silhouette lines, there is no entity representing curves in the display. Such entities cannot be selected.
What is displayed is a graphical representation of the HLR object. In some cases (e.g., silhouette lines) there is no real entity in the drawing database. These representational entities cannot, obviously, be used for Verify/Attributes.
The Hidden Line options in the View menu are greyed-out when you are in Layout mode. Each layout instance has its own rendering control.
Note: In past versions the instance-specific control could be set to Default in which case it use whatever was set in the general (View menu) rendering controls. There are now additional options available for hidden line renderings in layout instances, so the setting can no longer can be driven from the View Menu default setting.