Building part definitions determine the appearance of Mechanical discipline components in 3D models and drawings but do not determine the appearance of individual pieces within an drawing output element.

Mechanical discipline elements are not solid entities like forms. Section symbology and unification are not critical for creating drawings for the mechanical discipline. Mechanical discipline uses families of parts to apply discipline-specific data to components via the DataGroup System. Part information is considered when generating component geometry and the 2D add-on elements to form the graphical cells processed by drawing composition in dynamic views.