Download unit ii – three dimensional concepts

M.KUMARASAMY COLLEGE OF ENGINEERING
THALAVAPALAYAM, KARUR- 639 113
DEPARTMENT OF IT
SUBJECT: GRAPHICS AND MULTIMEDIA
STAFF NAME: M.PRIYADHARSHINI
SUBJECT CODE: CS1354
UNIT II – THREE DIMENSIONAL CONCEPTS
2 MARKS
1. Define Vanishing Point. (UNIV QUES MAY/JUN 2007)
The point at which a set of projected parallel lines appears to converge is
called a Vanishing Point.
2. Define Morphing. (UNIV QUES MAY/JUN 2007)
Transformation of object shapes from one form to another is called
Morphing. It applied to any motion or transition involving a change in shape.
3. List any two viewing parameters of a 3D Object. (UNIV QUES NOV/DEC
2007)
The viewing parameter of a 3D objects are
i.
Boundary representation
ii. Space-partitioning representation
4. Define the term complementary colors. (UNIV QUES NOV/DEC 2007)
Two different-color light sources with suitably chosen intensities can be
produce a range of other colors. If the two color sources combine to produce
white light, they are referred to as Complementary colors.
5. State the uses of chromaticity diagram. (UNIV QUES APR/MAY 2004)
The use of Chromaticity diagram is
i.
Comparing color gamut’s for different sets of primaries.
ii. Identifying complementary colors.
iii. Determining dominant wavelength and purity of a given color.
6. What is realism rendering? (UNIV QUES APR/MAY 2004)
Realism rendering is the way realism is attained in displays by setting the
surface intensity of objects according to the lighting conditions in the scene and
according to assigned surface characteristics.
7. Define Blending function.
Blending function or basic functions is that determines how specified
geometric constraints on the curve are combined to calculate positions along the
curve path.
8. How are polygon data stored in graphics applications? (UNIV QUES
NOV/DEC 2008)
Polygon data are placed into tables that are to be used in the subsequent
processing, display, and manipulation of the objects in a scene. Polygon tables are
organized into two groups: geometric tables and attribute tables.
9. What is Octree and Quadtree?
Octree is a hierarchical tree structure, used to represent solid objects in some
graphics system. Each node corresponds to a region of three-dimensional spaces,
when the tree structure is organized. The two dimensional representation of
Octree is Quadtree.
10. List out the properties of B-Spline curves.
i.
The polynomial curve has degree d-1 and Cd-2 continuity over the range of
u.
ii. For n+1 control points, the curve is described with n+1 blending
functions.
iii. Each blending function Bk,d is defined over d subintervals of the total
range of u, starting at knot value uk .
iv.
The range of parameter u is divided into n+d subintervals by the n+d+1
values specified in the knot vector.
v.
With knot values labeled as {u0, u1, ….,un+d}, the resulting B-Spline curve
is defined only in the interval from knot value ud-1 up to knot value un+1.
vi.
Each section of the spline curve is influenced by d control points.
vii.
Any one-control point can affect the shape of at most d curve section.
11. What are the different types of Transformations.
The different types of transformations are
i.
Translation
ii. Rotation
iii. Scaling
iv.
Reflection
v.
Shearing
12. Give the basic types of Projections.
The two basic projection methods are
i.
Parallel Projection
ii. Perspective projection.
13. What are the advantages of parallel projection? (UNIV QUES NOV/DEC
2008)
i. Used in drafting to produce scale drawings of three-dimensional objects.
ii. Accurate views of the various sides of an object are obtained.
14. Define Color model.
A Color model is a method for explaining the properties or behavior of
color within some particular context.
15. List out the steps in animation sequence.
An animation sequence is designed with the following steps
i.
Storyboard layout
ii. Object definitions
iii. Key-frame specification
iv.
Generation of in-between frames.
16. What is Scientific Visualization?
Scientific Visualization aids scientific and engineering analysis, involves the
visualization of data sets and processes that may be difficult or impossible to
analyze without graphical methods.
17. Define Volume rendering?
Volume rendering, is like an X-ray picture, is another method for
visualizing a three-dimensional data set. The interior information about a data set
is projected to a display screen using the ray-casting methods.
18. What is Voxels?
Individual elements of a three-dimensional space are called Volume
elements or Voxels.
19. List the various standard motions that simulate camera movements.
i.
Zooming
ii. Panning
iii. Tilting
20. What is Color gamut?
Color models that are used to describe combinations of lights in terms of
dominant frequency (hue) use three colors to obtain a reasonably wide range of
colors, called the Color Gamut for that model.
21. List out the various characteristics of Light.
i.
Dominant frequency or dominant wavelength
ii. Brightness
iii. Luminance
iv.
Purity or saturation
22. What for Ray-casting method is used?
Ray casting methods are commonly used to implement constructive solid
geometry operations when objects are described with boundary representations.
23. Give the advantages of B-spline over Bezier Curve
i.
The degree of a B-Spline polynomial can be set independently of the
number of control points.
ii. B-Splines allow local control over the shape of a spline curve or surface.
24. What is the different animation systems used by user?
i.
Key-frame System
ii. Parameterized System
iii. Scripting System
25. What is the use of Parameterized System?
Parameterized System allows object-motion characteristics to be specified
as part of the object definitions. The adjustable parameters control such object
characteristics as degree of freedom, motion limitations, and allowable shape
change.
26. Define surface rendering?
Surface rendering method is defined to mean procedure for applying a
lighting model to obtain pixel intensities for all the projected surface positions in
a scene in order to obtain the realism of the objects in the scene.
27. List some of the Color Models?
i.
XYZ Color model
ii. RGB Color Model
iii. YIQ Color Model
iv.
CMY Color Model
16 MARKS
1. Derive the 3D transformation matrix for rotation about
i. An arbitrary axis
ii. An arbitrary plane (UNIV QUES NOV/DEC 2007)
(OR)
Explain in detail about the 3D rotation including all cases. (UNIV QUES
APR/MAY 2004)
Page No: 409-418
2. Explain 3D basic transformation with an example. (UNIV QUES MAY/JUN
2007)
Page No: 408-413 and 420-422
3. Design a storyboard layout and accompanying key frames for an animation
of a single polyhedron. (UNIV QUES MAY/JUN 2007)
Page No: 588-594
4. How is ‘morphing’ animation performed? Discuss with an example. (UNIV
QUES NOV/DEC 2008)
Page No: 588-591
5. How to specify objects motion in an animation system. (UNIV QUES
MAY/JUN 2007)
Page No: 594-596
6. Explain RGB, CMY, YIQ, and YUV Color models. (UNIV QUES NOV/DEC
2007)
Page No: 572-575
7. What are Bezier curves? Discuss their properties. (UNIV QUES NOV/DEC
2008)
Page No: 327-334
8. Determine the Bezier blending function for three control points. Plot each
function and label the maximum and minimum values. (UNIV QUES
APR/MAY 2005)
(OR)
Determine the Bezier blending function for five control points. Plot each
function and label the maximum and minimum values. (UNIV QUES
APR/MAY 2004)
Page No: 327-334
9. Explain about B-Spline curves. Also discuss how this differs from that of the
Bezier Curves. (UNIV QUES APR/MAY 2005)
Page No: 334 345
10. What is Spline? Explain about uniform nonrational B-Spline. (UNIV QUES
MAY/JUN 2006)
Page No: 336-343
11. Explain about Quadtree and Octree representation. (UNIV QUES APR/MAY
2005) (OR)
How do you represent 3D objects using Octrees? (UNIV QUES NOV/DEC
2008)
Page No: 359-362
12. What do you mean by Perspective viewing. Explain with an example. (UNIV
QUES APR/MAY 2005)
Page No: 443-447
13. Write notes on HSV and HLS color models. (UNIV QUES NOV/DEC 2008)
Page No: 575-577,579-580.
14. What are the different color models defines with Primary colors. Explain the
color model based on specification of luminance and purity values. (UNIV
QUES APR/MAY 2005)
(OR)
Explain the color models defined with Primary colors. Explain the color
model based on specification of luminance and purity values. (UNIV QUES
APR/MAY 2004)
Page No: 569-573
15. Explain about the concept of realism rendering (UNIV QUES APR/MAY
2005)
Page No: 300
16. What is scientific visualization? Explain the various kinds of visualization
using scalar fields. (UNIV QUES MAY/JUN 2006)
Page No: 395-403
TEXT BOOK:
1.Donald Hearn and M.Pauline Baker,” Computer Graphics C Version”,
Pearson Education, 2003. (UNIT I- Chapter 1 to 6)