drafting

Precise graphical representation of a structure, machine, or its component parts that communicates the intent of a technical design to the fabricator (or the prospective buyer) of the product. Drawings may present the various aspects of an object's form, show the object projected in space, or explain how it is built. Drafting uses orthographic projection, in which the object is viewed along parallel lines that are perpendicular to the plane of the drawing. Orthographic drawings include top views (plans), flat front and side views (elevations), and cross-sectional views showing profile. Perspective drawing, which presents a realistic illusion of space, uses a horizon line and vanishing points to show how objects and spatial relationships might appear to the eye, including diminution of size and convergence of parallel lines. Drafting was done with precision instruments (T square or parallel rule, triangle, mechanical pens and pencils) until computerization revolutionized production methods in architectural and engineering offices.

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