PERSPECTIVE PROJECTION

Dept. of CA, NITT 2

Perspective Projection• Transform points along projection lines that meet @ PRP

• If we set, • PRP @ ZPRP along Zv axis• Place View Plane @ Zvp

PRP – Projection Reference Point

1

U – 0/1

Dept. of CA, NITT 3

Perspective Projection• If u=0, • X’=X• Y’=Y• Z’=Z• PRP (X,Y,Z)

• If u=1, • X’=0• Y’=0• Z’=ZPRP

• PRP (0,0,ZPRP)

Dept. of CA, NITT 4

Perspective Projection• Solve Z’ equation for parameter u @ this position along Pro.

Line

Substitute Eq. 2 in X’, Y’

2

3

Distance of VP from PRP : d=ZPRP-Zvp

Dept. of CA, NITT 5

Perspective Projection• Using 3D Homogeneous Coordinate representation

Where h=(ZPRP – Z) / dp

2 4

Distance of VP from PRP : d=ZPRP-Zvp

5

Dept. of CA, NITT 6