1. Prepared by: Nor Helya Iman Kamaludin Prepared by: Nor Helya Iman Kamaludin Lecture 4: Multiple Views 1 PTT 105/3: Engineering Graphics

2. Multiview Drawing  A multiview drawing is one that shows two or more two-dimensional views of a 3-D object.  Multiview drawings provide the shape description of an object.  When combined with dimensions, multiview drawings serve as the main form of communication between designers and manufacturers. 2PTT 105/3: Engineering Graphics

3. Multiview Drawing 3PTT 105/3: Engineering Graphics

4. Width, Depth, and Height All three-dimensional objects have width, height, and depth. Width is associated with an object’s side-to- side dimension. Height is the measure of an object from top- to- bottom. Depth is associated with front-to-back distance. 4 PTT 105/3: Engineering Graphics

5. Width, Depth, and Height PTT 105/3: Engineering Graphics

6. 45 ° Width, Depth, and Height 6PTT 105/3: Engineering Graphics

7.  Orthographic projection is a technique that is used to create multiview drawings.  Orthographic projection is any projection of the features of an object onto an imaginary plane of projection.  The projection of the features of the object is made by lines of sight that are perpendicular to the plane of projection.  The use of a 45° miter line and Projection Lines provide a quick, accurate method of drawing Orthographic Projection 7 PTT 105/3: Engineering Graphics

8.  Orthographic projection is the most commonly used drafting method because it describes shapes of objects completely and exactly PTT 105/3: Engineering Graphics8

9. The best way to understand orthographic projection is to imagine an object contained inside a glass box. Orthographic Projection 9PTT 105/3: Engineering Graphics

10.  There is a total of six glass walls surrounding the object.  Each wall represents a projection plane onto which a two- dimensional object view will be created. Orthographic Projection 10PTT 105/3: Engineering Graphics

11.  A projection plane, also referred to as a plane of projection or picture plane, is an imaginary surface that exists between the viewer and the object.  The projection plane is the surface onto which a two-dimensional view of a three- dimensional object is projected and created. Projection Plane 11PTT 105/3: Engineering Graphics

12.  Start by focusing only on the front projection plane.  A person standing in front of the object would see only the five corners identified in black. 1 2 3 4 5 line of sight at 90° angle to projection plane Orthographic Projection 12PTT 105/3: Engineering Graphics

13.  Projection lines are used to project each corner outward until they reach the projection plane. Orthographic Projection 13PTT 105/3: Engineering Graphics

14. imaginary line  A projection line is an imaginary line that is used to locate or project the corners, edges, and features of a three-dimensional object onto an imaginary two-dimensional surface. Projection Lines 14PTT 105/3: Engineering Graphics

15.  The visible edges of the object are then identified on the projection plane by connecting the projected corners with object lines. Orthographic Projection 15PTT 105/3: Engineering Graphics

16.  The orthographic projection process is then repeated on the other projection planes. Orthographic Projection 16PTT 105/3: Engineering Graphics

17. Sketching a Multiview Drawing  Sketching multiview drawing can be easily done using points, construction lines, and object lines. 17PTT 105/3: Engineering Graphics

18. Step #1:Calculate the amount of space that the views will take up. Sketching a Multiview Drawing 18PTT 105/3: Engineering Graphics

19. Calculating Required Space Overall Multiview Sketch Height? Overall Multiview Sketch Width? 18 spaces 12 spaces 19PTT 105/3: Engineering Graphics

20. Sketching a Multiview Drawing Step #1:Calculate the amount of space that the views will take up. Step #2:Layout the boxes within which the individual views will occur using points and construction lines. 20PTT 105/3: Engineering Graphics

21. Construction Line Layout 21PTT 105/3: Engineering Graphics

22. Sketching a Multiview Drawing Step #1:Calculate the amount of space that the views will take up. Step #2:Layout the boxes within which the individual views will occur using points and construction lines. Step #3:Identify the visible edges by drawing object lines on top of the construction lines. 22PTT 105/3: Engineering Graphics

23. Object Line Layout 23PTT 105/3: Engineering Graphics

24. POP QUIZ!!! PTT 105/3: Engineering Graphics24

25. A Question…  Each of the blocks at right has the same overall dimensions and color. What else do they have in common? 25PTT 105/3: Engineering Graphics

26. The Answer is… Each of the blocks at right has the same overall dimensions and color. What else do they have in common? They all have identical top views! 26PTT 105/3: Engineering Graphics

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