Pictorial representation Flra Hajdu B 406 hajdflsze hu

Pictorial representation Flóra Hajdu B 406 hajdfl@sze. hu

Content • Theory of shape description • Pictorial drawing • Axonometric • Oblique • Perspective 2021. 09. 03. Hajdu Flóra

Theory of shape description • In technical drawings various projection methods are used to represent objects • Projection is a method of representing visually a 3 D object on a 2 D drawing paper • Pictorial projection is a method of producing a 3 D object that shows 3 main faces 2021. 09. 03. Hajdu Flóra

Pictorial drawing • Oldest written method of communication • Used in design, production, assembly, service, sales • Used to • Explain complicated engineering parts • Help designer to work out problems in space • Train new employees • Speed up and clarify the assembly of a machine • Transmit ideas from one person to another • Develop the power of visualisation 2021. 09. 03. Hajdu Flóra

Types of pictorial drawings Pictorial drawing Axonometric 2021. 09. 03. Oblique Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Hajdu Flóra Drawing&Design Perspective

Axonometric projection • Projected view • The lines of sight are perpendicular to the plane of projection • 3 faces of a rectangular object are all inclined to the plane of projection • The projections of 3 principal axes may make any angle with one another except 90 o 2021. 09. 03. Hajdu Flóra

Axonometric projection 2021. 09. 03. Isometric Dimetric 3 principal faces and axes of the object are equally inclined to the plane of projection 2 principal faces and axes of the object are equally inclined to the plane of projection Hajdu Flóra Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design Trimetric All 3 faces and axes of the object make different angles with the plane of projection

Axonometric projection 2021. 09. 03. Hajdu Flóra

Dimetric (engineering) projection 2021. 09. 03. Hajdu Flóra

Developing an axonometric drawing 2021. 09. 03. Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design Hajdu Flóra

Oblique projection • Based on the procedure of placing the object with one face parallel to the frontal plane • Placing the other 2 views on oblique planes to left or right, top or bottom at a convenient angle • The 3 axes of projection are vertical, horizontal and receding • Advantage: showing one face without distorsion 2021. 09. 03. Hajdu Flóra

Oblique projection Faces to front: • The face with the greatest irregularity of outline or contour • The face with the greatest number of circular features • The face with the longest dimension Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design 2021. 09. 03. Hajdu Flóra

Oblique projection Cabinet Cavalier All lines are made to their true lengths Lines on the receding axis are shortened by one half their true length to compensate for distorsion scan 2021. 09. 03. Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design Hajdu Flóra

Cabinet projection 2021. 09. 03. Hajdu Flóra

Developing an oblique drawing (Cabinet) scan Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design 2021. 09. 03. Hajdu Flóra

Perspective projection • Perspective is a method of drawing that depicts a 3 D object on a flat plane as it appears to the eye • The drawing is made by the intersection of the picture plane with lines of sight converging from points on the object to the point sight which is located at a finite distance from the picture plane • Perspective drawings are more realistic • Commonly used for presentation, illustrations, architects 2021. 09. 03. Hajdu Flóra

Perspective projection 2021. 09. 03. Parallel Angular 1 vanishing point 2 vanishing points Hajdu Flóra Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design Oblique 3 vanishing points

Perspective projection Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design 2021. 09. 03. Hajdu Flóra

Construction of 2 -point perspective 2021. 09. 03. Hajdu Flóra

CAD • 3 D modeling • Generation of perspective drawings • The position of the , , camera’’ represents the person viewing the object • Several parameters (zoom, distance, view clip) are manipulated to create the required perspective view of the object • Only the view is manipulated the object remains unaffected 2021. 09. 03. Hajdu Flóra

Pictorial representaion examples (CAD) 2021. 09. 03. Hajdu Flóra

Pictorial representation examples 2021. 09. 03. Hajdu Flóra

Summary • Pictorial representation • Axonometric • Oblique • Perspective • Pictorial representation examples Next week: Ortographic representation, first angle and third angle projection

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