This presentation discusses different types of 3D projections, including parallel and perspective projections. It defines projection as mapping a 3D object onto a 2D plane using projection lines. Parallel projection uses parallel lines and preserves size, while perspective projection uses converging lines and preserves realistic proportions but not exact sizes. Perspective projection can be classified into one, two, or three vanishing point types depending on how many principal axes the projection plane intersects. Examples like Leonardo da Vinci's "The Last Supper" are used to illustrate perspective projection principles.

1. A presentation on Perspective
Projection( 3D Projection).
By-Pranjal Das.
MCA 4th semester
Roll no=19

2. Contents
Overview of 3D Projection.
Types of 3D Projection.
Brief introduction to Parallel projection.
Introduction to Perspective Projection.
What is Vanishing point ??
Types of Perspective Projection.
References.
Conclusion.

3. Overview of 3D Projection:
Projection is a method of mapping a 3 dimensional object into a 2
dimensional view plane.
Mapping is determined by the projection line called Projector.
“Projection can be defined as a mapping of point P(x, y, z) onto its
image P`(x`, y`, z`) in the projection plane, which constitute the display
surface.”

4. Types of 3D Projection:
Two types of projections are there.
 Those are Perspective projection and Parallel projection.
 Projection Reference Point(PRP) or Center of Projection point
is a point, where projection lines converges.

5. Brief introduction to Parallel projection:
In parallel projection, projection lines are parallel to each other.
Image on the view plane of the object will be equal size with the
object.

6.  Projection Reference Point(PRP) lies in infinite position.
Different types of parallel projection are given bellow:

7. Introduction to Perspective Projection:
Projection lines are drawn from the object point towards view plane.

8.  Image of the object in the view plane is smaller than the real object.
 PRP lies in finite position.
Realistic image relative proportion could not be preserved.
Commonly used by artists and the designers.

9. Let’s Observe some pictures closely.

14. What is Vanishing Point:
Parallel lines that are not parallel to the viewing plane, converges to a
Vanishing Point.

15. Example of Perspective projection:
The last Supper by Leonardo da Vinci.

17. Types of Perspective Projection:
Three types of Perspective Projection are there.
One Principal Vanishing Point Perspective Projection.
Two Principal Vanishing Point Perspective Projection.
Three Principal Vanishing Point Perspective Projection.

18. One Principal Vanishing Point Perspective
Projection:
This Perspective projection occurs when the projection plane intersect
to one of the Principal axis(x, y or z).

19. Example of one point vanishing:

20. Two Principal Vanishing Point Perspective
Projection:
This Perspective projection occurs when the projection plane
intersects exactly any two of the Principal axis(x, y or z).

21. Example of two point vanishing:

22. Three Principal Vanishing Point Perspective
Projection:
This Perspective projection occurs when the projection plane
intersects to all the three Principal axis(x, y and z).

23. Example of one point vanishing:

24. References:
https://en.wikipedia.org/wiki/3D_projection
Google
Bibliography:
Computer Graphics, C Version ,Second Edition by- Donald D. Hearn,
M. Pauline Baker.

25. Conclusion:
“Clearly, if wed had the kind of computer graphics
capability then that we have now, the Star Gate sequence
would be much more complex than flat planes of light
and color.”
- Douglas Trumbull.
https://www.youtube.com/watch?v=ebmwYqoUp44&t=125s

26. THANK YOU