The options on this page that is relevant to 3D is in the Display section. For the remaining options, see Display Options.
Draw form-building edges: When checked, the entire structure of 3D objects is shown. When not checked, the minimum number of edges needed to show the object will be displayed.
With form-building edges
Without form-building edges
Note: You can make selected edges non form-building with the Edit Tool. See Edit Tool in 3D.