Multi-view orthographic projections

Multi-view orthographic projections are a part of parallel projections. In this type of drawing, the observer is considered to be at an infinite distance. The projecting lines are thus parallel to one another. These projections are also orthographic since both the observer and the object are perpendicular to the projection plane.

Multi-view orthographic projections Another distinguishing element in multi-view projections is that one of the faces of the object to be drawn is placed parallel to the projection plane. That is why, in most cases, one must draw several views of the object to portray it completely. The observer can only see one side at a time.

Multi-view orthographic projections In technical drawing, the views are flat figures (two dimensions) that we see from directly in front of each object. Largeur Hauteur

Multi-view orthographic projections In the type of projections used in North America, we imagine the object being drawn in the center of a transparent box. The different views of the object are projected onto the sides of this box.

Multi-view orthographic projections One of these views is designated as the front view of the object. We usually choose the face that best portrays the object. The choice of the front view determines the placement of the other views.

Multi-view orthographic projections The projection box and its six views are spread in such a way as to place all the views on the same plane. The other views pivot around the front view. BOTTOM VIEW LEFT SIDE VIEW REAR VIEW FRONT VIEW RIGHT SIDE VIEW TOP VIEW

Multi-view orthographic projections Among the six possible views, we will choose to portray those necessary to the description of the shape of the object. FRONT VIEW RIGHT SIDE VIEW TOP VIEW VUE DE GAUCHE VUE ARRIÈRE BOTTOM VIEW Three views are usually enough to portray an object. Many simple objects may only require one or two views.

Multi-view orthographic projections TOP VIEW FRONT VIEW RIGHT SIDE VIEW Here is the usual representation of views in multi-view orthographic projections. This type of drawing is used in technology because it allows description without deforming the faces of objects.

One view shows only two dimensions. On the front view are height and length, on the top view, width and length and on the side view, width and height. LENGTHS Multi-view orthographic projections HEIGHTSHEIGHTS WIDTHSWIDTHS

LENGTHS HEIGHTSHEIGHTS WIDTHSWIDTHS FRONT VIEW RIGHT SIDE VIEW TOP VIEW LENGTHWIDTH HEIGHT WIDTH LENGTH

HEIGHTSHEIGHTS Multi-view orthographic projections TOP VIEW FRONT VIEW RIGHT SIDE VIEW This drawing technique is also quick for objects, because it allows dimensions to be projected from one view to the other.

LENGTHS Multi-view orthographic projections

WIDTHSWIDTHS TOP VIEW FRONT VIEW RIGHT SIDE VIEW The 45˚ line allows the widths of the top view to be carried over to the right side view or vice versa. 45º

Multi-view orthographic projections TOP VIEW FRONT VIEW RIGHT SIDE VIEW The 45˚ line allows the widths of the top view to be carried over to the right side view or vice versa. 45º

Bibliography GIESECKE, Frederick E., MITCHELL, Alva, SPENCER, Henry Cecil, HILL, Ivan Leroy, GYGDON, John Thomas et NGUYEN, Dinh N. « Dessin technique », Montréal, Éditions du Renouveau Pédagogique inc., 1982, 769 p. JENSEN, C.H. « Dessin industriel », Montréal, McGraw-Hill, 1972, 752 p. STIRLING, Norman. « Éléments de dessin industriel », Montréal, HRW, 1979, 372 p.