Multiview Projection • Projection a view of an object • Is a photograph enough to describe an object? • A number of views, systematically arranged. . .
Perspective Projection Source, at a definite distance.
Orthographic Drawing Source, at an infinite distance
Four Types of Projection
Six Standard Views TOP REAR RIGHT LEFT FRONT BOTTOM
Six Standard Views
Six Standard Views
Orthographic Drawing
Orthographic Drawing
Orthographic Drawing
Unfolding the Glass Box The Glass Box
Top & Right Side Views
Third Angle Projection A transparent picture plane is set up between object and the station point of an observer’s eye. T Mitter Line D/2 D/2 F D/2 R
Third Angle Projection Mitter line can only be used when the views are placed equidistantly. ? ? ?
First Angle Projection (Europe & Asia) The observer looks through the object to the planes of projection. R F D/2 D/2 Mitter Line T
Views of Surfaces • To effectively create and interpret multiview projections, you have to consider the elements that make up most solids: SURFACES bounded by straight lines, or curves.
Edge View
True View
Foreshortened View
Normal Surface Parallel to the plane of projection (true shape&size)
Perpendicular to a plane, but inclined or tipped to adjacent planes. Edge vien on perp. Plane, fs view on inclined planes Inclined Surface
Oblique Surface Tipped to all planes. FS on all planes.
True length in adjacent planes Point on perpendicular Plane. Normal Edge
True length in parallel plane (angled) Shortened on adjacent planes (vertical / horizontal) Inclined Edge
Shortened & Angled Oblique Edge
Angles
Vertices • A corner or point, intersection of 3 planes
Meaning of a Point • A vertex • Point view of an edge
Meaning of a Line Visible or hidden: • An edge (intersection between 2 surfaces) • Edge view of a surface • Limiting element of a curved surface
Hidden Lines Dashed hidden lines are used to represent features that would be hidden behind other surfaces.
Center Lines Used to indicate symmetrical axes of circles
Order of Drawing • Block out the views • Locate centerlines • Start details and arcs first • Draw dominant details • Check your views