Subject: Computer Graphics (NCS403)
Exam Type: Theory
Semester: IV (4th Semester)
Duration: 3 Hours
Maximum Marks: 100
Section A — Short Questions (10 × 2 = 20 Marks)
These are basic conceptual and definition-based questions testing core knowledge of computer graphics.
Topics covered:
Purpose and working of a video controller DDA algorithm — tracing a line from (0,0) to (-6, -6)
Definition of refresh buffer Transformation matrix for rotation about an arbitrary point in space
Proof of commutative property of successive rotations Function of shear transformation
Properties of B-spline curves Difference between specular reflection and diffuse reflection
Difference between viewport and window Explanation and examples of aliasing and antialiasing
Section B — Descriptive / Numerical Questions (5 × 10 = 50 Marks)
These are analytical and calculation-based questions involving algorithms and geometry.
Key questions:
Bresenham’s Line Drawing Algorithm: Derivation and comparison with DDA.
Display parameter problem: Calculation of Pixel aspect ratio
Frame buffer size Data transfer rate (KB/sec)
Window-to-Viewport transformation: Mapping coordinates with accurate diagrams.
Hidden surface removal algorithms: Scan-line vs. Depth buffer technique.
Cohen–Sutherland line clipping algorithm — step-by-step explanation.
Explanation of quadratic and polygonal surfaces.
Description of Warn model (lighting or shading model)
Section C — Long Analytical / Derivation Questions (2 × 15 = 30 Marks)
Transformation Composition:
Given figures A(-2,0), B(0,-2), C(-2,-4), D(-4,-2) transformed to A'(1,-1), B'(3,3), C'(6,3), D'(4,-1) using a composite transform (T₂ × H₁ × S₁ × R₁ × T₁).
Write all transformation matrices Reduce to a single scale, rotation, and translation matrix
Area Subdivision Algorithm:
Explanation with suitable diagram Advantages and disadvantages
Visible Surface Detection Methods:
Detailed discussion on all visibility determination algorithms used in 3D rendering
Major Topics Covered
Line drawing algorithms (DDA, Bresenham)
2D and 3D geometric transformations (rotation, scaling, translation, shearing)
Window-to-viewport mapping Hidden surface removal
Surface modeling (quadratic, polygonal) Shading models (specular, diffuse, Warn)
Line clipping (Cohen–Sutherland) Area subdivision and visible surface detection
Purpose of the Paper
This exam checks both theoretical and practical understanding of 2D/3D graphics, including transformation algorithms, rendering concepts, and visualization principles.
Students must be comfortable with matrices, coordinate geometry, and algorithms for drawing, clipping, and transforming objects on a computer screen.
