Lecture Autodesk inventor Projection theory Perspective and parallel projections

Projection Theory
Perspective and Parallel Projections


Projection Theory
A projection is a mapping of a 3D space onto a 2D subspace
2D space is called the projection plane
Projection also refers to image resulting from such a
mapping


Classification of Projections
P r o je c t io n T h e o r y

P e r s p e c t iv e
P r o je c t io n
O n e - p o in t
T w o - p o in t
T h r e e - p o in t

P a r a lle l
P r o je c t io n
O b liq u e
C a v a lie r
C a b in e t
G e n e ra l

O r t h o g r a p h ic
A x o n o m e t r ic
I s o m e t r ic
D im e t r ic

T r im e t r ic

M u lt iv ie w


Common Elements of a Projection System
Center of Projection
(Perspective)/Direction of
Projection (Parallel)
Projection Plane
Object(s) to be projected
Projectors


Some Terminology
Bounding Box = Principal Enclosing Box (PEB)
Center of Projection = Station Point = Viewpoint
of observer
Projection Plane = Viewplane = Picture Plane
Projectors = Sightlines = Line of Sight


Projection Theory

Perspective and Parallel Projections