Create drawings from models (Creo Elements/Direct Annotation) > Normal, hidden, and tangent lines
  
Normal, hidden, and tangent lines
The default settings governing the appearance of normal, tangent, and hidden lines in new views are all managed in the Drawing/View Default Settings table (under Annotation > View > Appearance).
Creo Elements/Direct Annotation designates lines in views as Normal, Hidden, and Tangent.
Normal lines are all the normal visible lines of view geometry, as opposed to hidden lines and tangent edges.
Hidden lines represent view geometry hidden by other view geometry obstructing it (for example, the edges in the interior of a shelled part).
Tangent lines represent the edges that are formed where a curved surface meets an adjoining flat or curved surface at a tangent (for example, the edges of a blend).
Note that you cannot set the line attributes for hidden lines when the Line Type is set to Invisible or Not calculated.
Note also that dependent views (detail, section, partial, and cutaway views) take their settings from their parent views, not from the default view settings.