Test Bank—Chapter Ten (Computer Graphics)
Multiple Choice Questions
1. Which of the following is not associated with a parallel projection?
A. Projection plane
B. Projectors
C. Center of projection
D. All of the above
2. The image is stored in the
A. Image window
B. Z-buffer
C. Center of projection
D. Frame buffer
3. The shape of an object is usually represented by
A. A sphere
B. A polygonal mesh
C. A triangle
D. A texture map
4. A polygonal mesh consists of
A. Planer patches
B. Pixels
C. Spheres
D. Bezier curves
5. Which of the following is not a way of constructing a polygonal mesh?
A. Digitizing
B. Procedural model
C. Texture mapping
D. Particle system
6. Which of the following is not contained in a scene graph?
A. Models of the objects in the scene
B. Information about the camera
C. Information about lighting
D. The view volume
7. The incidence angle is measured relative to
A. The line normal to the surface
B. A line parallel to the surface
C. The line followed by the reflected ray
D. None of the above
8. The phenomenon of a light ray bending as it passes through materials of different density is called
A. Reflection
B. Incidence
C. Refraction
D. Ray tracing
9. Which of the following is not naturally handled by a local lighting model?
A. Specular light
B. Diffuse light
C. Ambient light
D. Shadows
10. Which of the following is not a step in the traditional rendering pipeline?
A. Scan conversion
B. Rasterization
C. In-betweening
D. Clipping
11. Which of the following is associated with clipping?
A. Phong shading
B. The view volume
C. Texture mapping
D. Bump mapping
12. Which of the following is not associated with scan conversion?
A. A z-buffer
B. The painter’s algorithm
C. Digitizing
D. Pixel positions
13. Another name for scan conversion is
A. Rasterization
B. Digitizing
C. Bump mapping
D. Ray tracing
14. Hidden-surface removal is the process of
A. Discarding those objects that fall outside the view volume
B. Applying a parallel projection rather than a perspective projection
C. Identifying parts of surfaces that are in a shadow
D. Identifying surfaces that are blocked from the camera’s view
15. Which of the following is the simplest shading technique?
A. Phong shading
B. Flat shading
C. Gouraud shading
D. Bump mapping
16. Which of the following is an advantage of ray tracing over the traditional rendering pipeline?
A. It is less time consuming.
B. It implements a local lighting model.
C. It can be implemented in real time.
D. It implements a global lighting model.
17. Which is not a feature of radiosity?
A. Objects tend to appear dull rather than shiny.
B. Moving the camera position does not require massive changes.
C. Specular light is easily simulated.
D. It is a computationally complex undertaking.
18. Which of the following is not a property of the rendering pipeline?
A. It relies on recursive ray tracing.
B. It implements a local lighting model.
C. It is often implemented in firmware.
D. Its use leads to efficient rendering systems.
19. Producing a sequence of frames to fill the gap between key frames is called
A. Storyboarding
B. Morphing
C. In-betweening
D. Motion capture
20. Motion capture is a means of applying
A. A global lighting model
B. A local lighting model
C. Dynamics
D. Kinematics
21. Avars are used to
A. Adjust a character’s shape
B. Simulate textured surfaces
C. Locate objects in a scene graph
D. Reposition the camera
Fill-in-the-blank/Short-answer Questions
1. The subfield of computer graphics that involves producing images of virtual worlds is called _______.
2. The modeling process concludes with the construction of a ______________, which is a data structure
containing models of all the objects in a scene as well as camera information.
3. The shape of an object is typically represented by means of a ____________, which represents the shape
as a collection of flat surfaces.
4. Suppose each row below represents the vertices of a planar patch. What three vertices would describe a
planar patch that would complete the polygonal mesh?
_________ __________ _________
(0, 0, 0) (1, 0, 0) (0, 0, 1)
(0, 0, 0) (0, 1, 0) (0, 0, 1)
(0, 0, 0) (0, 1, 0) (1, 0, 0)
5. A _________ is a procedural model that uses numerous small particles to simulate an object.
6. The shading technique called __________ produces a faceted image.
7. Bright highlights on an object are produced by __________ light.
8. Clipping is the process of restricting attention to objects (or parts of objects) that are within the
___________.
9. Another name for scan conversion is ____________.
10. The ____________ represents the portion of the projection plane that will contribute to the final image.
A bit map of that image is stored in the ___________.
11. A storage area called a __________ is often used to record distance information to be used in hidden-
surface removal.
12. The ________ algorithm is a simple approach to performing hidden-surface removal.
13. A line perpendicular to a surface is called a __________.
14. An alternative to flat shading is ______________.
15. The steps of clipping, hidden-surface removal, and shading are often referred to collectively as the
_______________.
16. Although __________ implements a global lighting model, it is time consuming and gives undue
emphasis to specular light.
17. Although __________ implements a global lighting model, it is time consuming and gives undue
emphasis to diffuse light.
18. Each of the images used to produce an animated sequence is called a _________.
19. An animation project usually starts by constructing a _________, which consists of a collection of
images that represent significant points in the sequence.
20. Producing animation frames by computing the effects of forces is an application of __________.
21. Producing animation frames by simulating the movements of joints and appendages is an application of
___________.
Vocabulary (Matching) Questions
The following is a list of terms from the chapter along with descriptive phrases that can be used to produce
questions (depending on the topics covered in your course) in which the students are ask to match phrases
and terms. An example would be a question of the form, “In the blank next to each phrase, write the term
from the following list that is best described by the phrase.”
Term Descriptive Phrase
image window The region of the projection plane containing the image
frame buffer Contains a bit map of the image
polygonal mesh Represents an object’s shape
procedural model A means of constructing an object’s shape
texture mapping A means of associating a predetermined image with a surface
scene graph Contains models of all the objects in a scene
specular light Produces the appearance of bright highlights on a surface
diffuse light Light that is reflected in many directions
rendering pipeline A collection of relatively standard rendering activities
clipping Reducing attention to only those objects that may appear in an image
scan conversion Associating pixel positions with points in a scene
painter’s algorithm An elementary means of hidden surface removal
z-buffer Contains information regarding distance from camera to objects
bump mapping A means of simulating texture by varying the orientation of a surface
local lighting model Disregards light interactions among objects
ray tracing A means of implementing a global lighting model
storyboard A means of outlining an entire animation sequence
dynamics A means of analyzing motion based on laws of physics
General Format Questions
1. Design a polygonal mesh for a cube. Represent each planar patch as a list of vertices in traditional
rectangular coordinates.
2. Compare the application of dynamics and kinematics in the field of animation.
3. Compare various approaches to shading.
4. Summarize the rendering pipeline.
5. Discuss some fundamental differences between the process of constructing models and assembling a
scene graph as opposed to rendering the scene.