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1. Unit 1
Basic of computer graphics
By: Medhavi Pandey

2. Outline
▪ Numerical on types of Transformation
▪ SheRotation aring
▪ Scaling
▪

3. X-Shear
• The transformation matrix for X-Shear can be represented as:-
• Xsh = 1 Shx 0
0 1 0
0 0 1
• X' = X + ShX . Y
• Y’ = Y

4. Y-Shear
• The Y-Shear can be represented in matrix from as −
• Ysh = 1 0 0
Shy 1 0
0 0 1
• Y' = Y + Shy . X
• X’ = X

5. Numerical Practice

7. 2D SCALING
• The scaling factor SX, SY scales the object in X and Y direction
respectively. The above equations can also be represented in matrix
form as below −
• (X′Y′)= (XY) Sx 0
0 Sy
[X' = X . SX and Y' = Y . SY ]
OR P’ = P . S

9. 2D ROTATION
• Representing the above equation in matrix form,
• [X′Y′]=[XY] cosθ sinθ
-sinθ cosθ
OR, P’ = P . R

10. 2D ROTATION
• The rotation angle can be positive and negative.
• For positive rotation angle, we can use the above rotation matrix. However, for
negative angle rotation, the matrix will change as shown below −
• R= cos(−θ) sin(−θ)
− sin(−θ) cos(−θ)
cosθ −Sinθ (∵cos(−θ)=cosθand sin(−θ)=−sinθ)
R=
Sinθ cosθ

13. THANK YOU