PROJECTIONS

PROJECTIONS

Perspective Projection Parallel projection Perspective Projection

Orthographic Projection (Multiview Projection) 4

Different Viewpoint

Orthographic Projection

Standard 2D views

The Principal Dimensions of an Object

Third Angle Projection First Angle Projection USA, Canada First Angle Projection Europe, Asia

Third Angle Projection First Angle Projection USA, Canada First Angle Projection Europe, Asia

Standard Views of Primitive Solids

View Orientation Good orientation Poor orientation

Select the most descriptive views Use minimum number of views to describe the object

Conventional Practices - Intersections

45o line drawn from point O Miter Lines Miter lines are used to transfer depth information. 45o line drawn from point O O Standard multiviews

Fillets, Rounds & Chamfers

Top view

Edge Lines – Principal & Inclined Principal lines appear vertical, horizontal or as point views. Inclined lines appear inclined in one view. 2

Oblique line appears inclined in all views Edge Lines – Oblique Oblique line appears inclined in all views

Principal Planes Principle planes are parallel to principal orthographic planes

Inclined Planes Inclined planes are perpendicular to two opposite orthographic planes.

Oblique Planes Oblique planes are neither parallel nor perpendicular to any principal orthographic planes.

Type of Planes Oblique Principal Inclined

Edge View of a Plane Principal planes appear in true size in one plane and as an edge view in the other two planes.