UGC NET - Computer graphics: display devices, line and circle algorithms, polygon fill, boundary-flood-fill, 2-D and 3-D transforms, viewing, clipping, spline and Bezier representations, illumination and rendering. Online Test (MCQ Quiz)

1. Which of the following is a common type of raster graphics display device?

A) Cathode Ray Tube (CRT) monitor B) Liquid Crystal Display (LCD) monitor C) Organic Light-Emitting Diode (OLED) monitor D) All of the above

2. In the context of computer graphics, what does 'raster' refer to?

A) A vector image format B) A grid of pixels C) A type of 3D model D) A rendering algorithm

3. Which algorithm is commonly used to draw a straight line on a raster display?

A) Bresenham's line algorithm B) Midpoint circle algorithm C) DDA (Digital Differential Analyzer) algorithm D) Both A and C

4. Bresenham's line algorithm is preferred over DDA for line drawing on raster displays primarily because it:

A) Uses floating-point arithmetic B) Requires only integer arithmetic C) Is computationally more complex D) Generates more pixels for the same line length

5. The Midpoint Circle Algorithm is an efficient method for generating:

A) Ellipses B) Parabolas C) Circles D) Hyperbolas

6. What is the primary goal of a polygon fill algorithm?

A) To outline the polygon edges B) To determine the visible surfaces of the polygon C) To color the interior of a polygon D) To transform the polygon in 3D space

7. Which polygon fill algorithm starts from a seed point inside the polygon and fills outward until it reaches a boundary color?

A) Scan-line fill B) Boundary fill C) Flood fill D) Both B and C

8. The boundary fill algorithm requires which of the following as input?

A) A seed point and the interior color B) A seed point and the boundary color C) The polygon vertices and the fill color D) The polygon vertices and the boundary color

9. Flood fill algorithm fills an area of a uniform color with a new color. It is similar to boundary fill but differs in:

A) The number of pixels it fills B) The stopping condition C) The input parameters D) Its computational complexity

10. In 2D transformations, what does a translation operation do?

A) Resizes an object B) Rotates an object C) Moves an object from one position to another D) Shears an object

11. A scaling transformation in 2D graphics changes the:

A) Position of an object B) Orientation of an object C) Size of an object D) Shape of an object

12. Which 2D transformation rotates an object around a fixed point?

A) Translation B) Scaling C) Rotation D) Shearing

13. A shear transformation in 2D graphics:

A) Changes the size of an object B) Changes the orientation of an object C) Distorts the shape of an object along an axis D) Moves an object without changing its shape or size

14. To perform complex transformations like rotation around an arbitrary point, we typically use:

A) A single transformation matrix B) A sequence of basic transformations C) Only translation and scaling D) A different algorithm for each case

15. In 3D transformations, translation is achieved by adding offsets to the:

A) X and Y coordinates B) X and Z coordinates C) Y and Z coordinates D) X, Y, and Z coordinates

16. Which 3D transformation changes the size of an object along one or more axes?

A) Rotation B) Translation C) Scaling D) Shearing

17. Rotating an object in 3D space can be performed around:

A) Only the X-axis B) Only the Y-axis C) Only the Z-axis D) The X, Y, or Z axis, or any arbitrary axis

18. Homogeneous coordinates are often used in computer graphics to represent 3D transformations because they:

A) Simplify rotation calculations B) Allow translation to be represented by matrix multiplication C) Reduce the number of calculations needed D) Improve the resolution of the display

19. In 3D graphics, the 'viewing transformation' is responsible for:

A) Determining the color of objects B) Defining the position and orientation of the camera C) Applying lighting effects D) Filling the polygons

20. The 'viewing pipeline' in 3D graphics typically involves several stages. Which stage follows the modeling transformation?

A) Projection transformation B) Rasterization C) Clipping D) Viewing transformation

21. What is the purpose of the 'projection transformation' in 3D viewing?

A) To model the 3D scene B) To remove hidden surfaces C) To convert 3D coordinates to 2D screen coordinates D) To apply shading

22. Which type of projection preserves parallel lines but can distort relative sizes?

A) Perspective projection B) Orthographic projection C) Isometric projection D) Oblique projection

23. Perspective projection simulates the way the human eye perceives depth by making objects:

A) Appear larger as they move further away B) Appear smaller as they move further away C) Maintain their original size regardless of distance D) Change color with distance

24. What is the primary function of a 'clipping' operation in computer graphics?

A) To color objects B) To remove parts of objects that are outside a specified region C) To rotate objects D) To apply textures

25. A 'view volume' or 'clipping volume' defines the region of space that:

A) Will be rendered as black B) Will be visible to the camera C) Will be transformed D) Will be filled with a specific color

26. The Cohen-Sutherland algorithm is a popular method for:

A) Polygon filling B) Line clipping C) Circle drawing D) 3D rotation

27. Which clipping algorithm is generally more efficient for clipping lines against a rectangular window?

A) Liang-Barsky algorithm B) Sutherland-Hodgman algorithm C) Cohen-Sutherland algorithm D) Weiler-Atherton algorithm

28. Spline representations are used in computer graphics to:

A) Create straight lines B) Model complex curves and surfaces smoothly C) Perform 3D transformations D) Fill polygons with solid colors

29. A Bezier curve is defined by a set of control points. The curve:

A) Passes through all control points B) Is influenced by control points but doesn't necessarily pass through all of them C) Is always a straight line D) Is approximated by straight line segments

30. The degree of a Bezier curve is determined by:

A) The number of control points minus one B) The number of control points C) The number of control points plus one D) The resolution of the display

31. Which of the following is a common type of spline used in computer graphics?

A) B-spline B) Bezier curve C) NURBS (Non-Uniform Rational B-Splines) D) All of the above

32. Illumination models in computer graphics are used to:

A) Define the shape of objects B) Determine how light interacts with surfaces C) Remove hidden surfaces D) Transform objects in 3D space

33. The Phong illumination model incorporates which of the following components?

A) Ambient, diffuse, and specular reflection B) Only diffuse reflection C) Only specular reflection D) Ambient and diffuse reflection only

34. Ambient light in an illumination model represents:

A) Light coming directly from a light source B) Light that has bounced off surfaces multiple times, providing general illumination C) Light that is reflected specularly D) Light that is blocked by objects

35. Diffuse reflection in illumination models simulates light that:

A) Reflects equally in all directions B) Reflects in a mirror-like fashion C) Is absorbed by the surface D) Is emitted by the surface

36. Specular reflection is responsible for:

A) The overall brightness of a surface B) The color of a surface C) Highlights and shininess on a surface D) Shadows cast by objects

37. Rendering refers to the process of:

A) Defining the geometry of a 3D scene B) Creating a 2D image from a 3D scene description C) Transforming objects D) Clipping parts of the scene

38. Ray tracing is a rendering technique that:

A) Simulates light rays bouncing off surfaces B) Uses scan-lines to draw polygons C) Only considers ambient light D) Is computationally inexpensive

39. Rasterization is a rendering technique that:

A) Projects 3D primitives onto a 2D image plane and fills pixels B) Traces light rays through a scene C) Requires complex mathematical calculations for every pixel D) Is typically used for non-real-time rendering

40. Which rendering technique can produce realistic reflections and refractions?

A) Basic scan-line rendering B) Ray tracing C) Wireframe rendering D) Gouraud shading

41. What is the purpose of a 'frame buffer' in a display system?

A) To store the display's refresh rate B) To hold the color information for each pixel on the screen C) To manage input devices D) To perform 3D transformations

42. Vector graphics display devices represent images using:

A) A grid of pixels B) Mathematical descriptions of lines, curves, and shapes C) Bitmaps D) Polygon meshes

43. In Bresenham's line algorithm, the decision parameter is used to determine:

A) Which pixel to choose next B) The color of the line C) The starting point of the line D) The angle of the line

44. The Sutherland-Hodgman algorithm is primarily used for clipping:

A) Lines against a convex polygon B) Polygons against a convex clipping window C) Points against a window D) Circles against a rectangle

45. Which of the following is a characteristic of B-spline curves?

A) They pass through all their control points. B) They are defined by a single polynomial equation. C) They offer local control over the curve's shape. D) They are always closed curves.

46. The Gouraud shading model calculates lighting at the:

A) Vertex of each polygon B) Center of each polygon C) Center of each pixel D) Each edge of the polygon

47. Phong shading calculates lighting at the:

A) Vertex of each polygon B) Center of each pixel C) Center of each polygon D) Each edge of the polygon

48. What is the Z-buffer algorithm primarily used for?

A) Polygon filling B) Line clipping C) Hidden surface removal D) Texture mapping

49. In 3D graphics, the 'projection plane' is:

A) The surface onto which the 3D scene is projected B) The object being viewed C) The light source D) The clipping window

50. Which type of display device uses a beam of electrons to illuminate phosphors on a screen?

A) LCD B) LED C) CRT D) OLED

Computer graphics: display devices, line and circle algorithms, polygon fill, boundary-flood-fill, 2-D and 3-D transforms, viewing, clipping, spline and Bezier representations, illumination and rendering. - Online Test

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