Upcoming SlideShare
×

# Projection

3,516 views

Published on

5 Likes
Statistics
Notes
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

Views
Total views
3,516
On SlideShare
0
From Embeds
0
Number of Embeds
4
Actions
Shares
0
214
0
Likes
5
Embeds 0
No embeds

No notes for slide

### Projection

1. 1. Projection By Altaf Ahmed By Altaf Ahmed, email: the.nothingness@hotmail.co m
2. 2. By Altaf Ahmed, email: the.nothingness@hotmai l.com OVERVIEW • • • • • Definition Taxonomy Terms used Parallel Projection Perspective Projection
3. 3. By Altaf Ahmed, email: the.nothingness@hotmai l.com Projection • Theoretically projection can b defined as”The mapping of a 3-D object having points P(x,y,z) onto its image P’(x’,y’,z’) in the projection plane or view plane, which constitutes the display surface”.
4. 4. By Altaf Ahmed, email: the.nothingness@hotmai l.com TAXONOMY Projection Perspective Projection Parallel Projection Oblique Orthographic Axonometric Multi-view One Point General Two Points Isometric Di-metric Trimetric Cabinet Cavalier Three Points
5. 5. By Altaf Ahmed, email: the.nothingness@hotmai l.com TERMS USED • • • • • View Plane Point of View Projector Centre of Projection Direction of Projection
6. 6. By Altaf Ahmed, email: the.nothingness@hotmai l.com Methods of Projection • Two methods are used to solve the basic problems of pictorial representation; 1. Parallel Projection 2. Perspective Projection
7. 7. By Altaf Ahmed, email: the.nothingness@hotmai l.com PARALLAL PROJECTION • • • • In parallel projection Direction of Projection is same for all points All projectors are parallel to each others Used by Drafter and Engineers to create working drawings of an object which preserves its scale and shape.
8. 8. By Altaf Ahmed, email: the.nothingness@hotmai l.com
9. 9. By Altaf Ahmed, email: the.nothingness@hotmai l.com
10. 10. By Altaf Ahmed, email: the.nothingness@hotmai l.com • Types of Parallel Projection 1. Orthographic Projection 2. Oblique Projection
11. 11. By Altaf Ahmed, email: the.nothingness@hotmai l.com Orthographic Projection • When the Direction of Projection is perpendicular ( at 90◦) to the view plane, then the projection is Orthographic Projection.
12. 12. By Altaf Ahmed, email: the.nothingness@hotmai l.com
13. 13. By Altaf Ahmed, email: the.nothingness@hotmai l.com Types of Orthographic Projections • • Multi-View Orthographic Projection Axonometric orthographic projections
14. 14. By Altaf Ahmed, email: the.nothingness@hotmai l.com Multi-View Orthographic Projections • Orthographic projections that show only one side of an object are called multiview orthographic projections • When direction of projection is parallel to any principal axis, this produces front, top and side view of an object
15. 15. By Altaf Ahmed, email: the.nothingness@hotmai l.com
16. 16. By Altaf Ahmed, email: the.nothingness@hotmai l.com Axonometric Projection • Orthographic projections that show more than 1 side of an object are called axonometric orthographic projections • In axonometric orthographic projections, the direction of projection is not parallel to any of the principal axis.
17. 17. By Altaf Ahmed, email: the.nothingness@hotmai l.com Continued….. • Sub categories of Axonometric orthographic Projections are; 1. Isometric 2. Di-metric 3. Trimetric
18. 18. By Altaf Ahmed, email: the.nothingness@hotmai l.com Continued….. • Isometric Projection: The direction of projection makes equal angles with all of the principal axis.
19. 19. By Altaf Ahmed, email: the.nothingness@hotmai l.com Continued….. • Di-metric Projection: The direction of projection makes equal angles with exactly two of the principal axis.
20. 20. By Altaf Ahmed, email: the.nothingness@hotmai l.com Continued….. • Trimetric Projection: The direction of Projection makes unequal angles with the principal axis.
21. 21. By Altaf Ahmed, email: the.nothingness@hotmai l.com Oblique Projection • Parallel projections that does not intersect the view plane perpendicularly • Direction of Projection is perpendicular to view plane
22. 22. By Altaf Ahmed, email: the.nothingness@hotmai l.com Continued….. • Special Cases of Oblique Projection 1. Cavaliar 2. Cabinet
23. 23. By Altaf Ahmed, email: the.nothingness@hotmai l.com Continued….. • Cavalier: the direction of projection is chosen so that there is no fore-shortening of lines perpendicular to the xy-lane • It is achived by projecting the projectors at an angle of 45◦
24. 24. By Altaf Ahmed, email: the.nothingness@hotmai l.com Continued….. • Cabinet: the direction of projection is chosen so that the line perpendicular to the xy-plane are fore-shortening by half of their length. • For cabinet projection the angle is kept 63.40◦
25. 25. By Altaf Ahmed, email: the.nothingness@hotmai l.com PERSPECTIVE PROJECTION • Projectors are not projected perpendicular to the view plane • Objects closer to view looks larger • Parallel lines appear to converge at a single point
26. 26. By Altaf Ahmed, email: the.nothingness@hotmai l.com
27. 27. By Altaf Ahmed, email: the.nothingness@hotmai l.com • • • • Subtypes One-point Two-points Three-points
28. 28. By Altaf Ahmed, email: the.nothingness@hotmai l.com • One point : This perspective projection occurs when the projection plane is perpendicular to one of the principle axis • Two points: this perspective projection occurs when the projection plane intersects exactly two of the principal axis. • Three points: this perspective projection occurs when the projection plane intersect all the three principal axes, x,y and z axes.
29. 29. By Altaf Ahmed, email: the.nothingness@hotmai l.com