Vu All Subjects Assignment Quiz GDB Handouts Available here
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We hope that you are doing well and staying safe. Our course team have scheduled the Semester In this post we are providing you Quiz 3 will be opened on January 24, 2023 and it will be closed on January 25, 2023.
When we need an
object to "glow" in a scene, we can do this with ------------ light.
Emissive
If we want any
object to glow, we should use ________________ lights.
Emissive
Light in the
real worlds loses its --------- as the inverse square of the distance.
Intensity
The ColorSpace tool is a handy
tool that we can use to interactively add two colours together to see the
effects of the various strategies for handling oversaturated colours.
True
______________ is simply the
calculation of color reflected by the surface.
Shading
When you hit a surface in ray
tracing, generally shadow rays are tested against all objects in a scene. If
these rays come back saying they hit an object in the scene, which of the
following do you do?
Add only the ambient light from
that light source to the object
There are not many different
ways of representing the intensity of a particular colour element.
False
In Perspective Projection the
screen plane must be parallel to the__________________.
X-Y plane
___________ light is reflected
in all directions from surface.
Diffuse
The reflected light wave turns
out to be a / an ______________ case since light is reflected at the same angle
as the incident wave (when the surface is smooth and uniform, as we'll assume
for now).
Simple
_______________ sets the
reshape callback for the current window. The reshape callback is triggered when
a window is reshaped.
glutReshapeFunc
A space curve can be confined
to a plane.
No
To convert the information in
the A matrix into that required for the P matrix, we do some simple matrix
algebra, First we have UA=UNP then Simply A = -------------
NP
Perspective projection is
specified with the function glFrustum().
Yes
Choose a camera lens or adjust
the zoom
projection transformation
Using a lighting model based
upon the Blinn Phong model means that we'll always get a uniform specular
highlight based upon the colour of the --------------- light and material,
which means that all reflections based on this model, will be reminiscent of
plastic.
Refracting
Refractive index is a function
of temperature, mostly due to density changes in materials with changes in
temperature.
True
To convert the information in
the A matrix into that required for the P matrix, we do some simple matrix
algebra. First we have GP = ------------------------------
UNP
Length L depends on the angle
alpha and the z coordinate of the point to be projected and L can be
represented by --------------------.
z * 1/ tan (alpha)
The traditional approach in
real-time computer graphics has been to calculate lighting at a vertex as a sum
of the ________ light.
Ambient, diffuse, and specular
Another way to define a space
curve by using intermediate points and the tangents at each end for making the
curve
No
An independent consortium, the
OpenGL Architecture Review Board, guides the OpenGL specification. With broad
industry support, OpenGL is the only truly open, vendor-neutral, ---------------
graphics standard.
Multiplatform
glut Reshape Window requests a
change in the size of the current window. The width and height parameters are
size extents in pixels. The width and height must be ---------------- values.
Positive
A space curve is not confined
to a plane. It is free to twist through space. To define a space curve we must
use parametric functions that are ----------------------.
Cubic polynomials
Refractive index is a function
of temperature, mostly due to changes in ---------------------- of materials
with changes in temperature. A simple correction can be applied in most
circumstances to allow us to use a value given at one temperature at another.
density
If we assign a different value
to the parametric variable for the intermediate point, then we obtain different
values for the coefficients. This, in turn, means that a different curve is
produced, although it passes through the -------------- three points.
same
Signed integer color
components, when specified, are linearly mapped to floating-point values such
that the most positive representable value maps to 1.0, and the most negative
representable value maps to ------------------. Floating-point values are mapped
directly.
1.0
The attenuation formula is f
=------------------------, where C, L and Q are the constand, linear and
quadratic attenuation factors and d is the distance between the vertex being
lit and the light source.
1/(C + Ld + Qd2)
End points and an intermediate
point on the curve, then we now --------------------- quantities that we can
express in terms of these coefficients (3 points x 3 coordinates each), and we
can use these three points to define a unique curve.
Nine
Geometric patterns that is
repeated at ever smaller scales to produce irregular shapes and surfaces are
called ___________
Fractals
Which of the following is NOT a
modern application for Computer Graphics-------------------?
Stop-motion animation
TV series are made as simply as
possible from the animation point of view. This approach is generally known as
------------------------.
Limited animation
An eight frame run cycle that
------------------ frame/frames to each step gives a fast and vigorous dash. At
this speed the successive leg positions are quite widely separated and may need
dry brush or speed lines to make the movement flow.
Four
reflection is the effect of
reflecting light toward the direction from which it came, no matter the orientation
of the surface.
Retro
Tessellation can be adaptive to
the _______ degree of curvature of a surface.
Local
An orthogonal set of
vectors--------------------------
Must be a set of linearly
independent vectors
Bezier curve is numerically the
----------------------- of all the polynomial-based curves used in these
applications.
Most stable
Bezier curve is the ideal
standard for representing the ---------------------------- piecewise polynomial
curves.
More complex
Keep polygon orientations
consistent to make sure that when viewed from the outside, all the polygons on
the surface are oriented in the same direction.
Same
The ---------------- is most
simple example that exhibits the property self-similarity.
Fern
A common mistake people make
when creating three-dimensional graphics is to start thinking too soon that the
final image appears on a flat, two-dimensional screen. Avoid thinking about which
pixels need to be drawn, and instead try to visualize ----------------- space.
Three-dimensional
Which of the following
properties of rational Bezier curves fails if the weight assigned to a control
point is negative?
Convex-Hull
In the Phong reflection model,
there are 3 constants (a, b, c) which are used to describe the qualities of
which of the following phenomena?
The attenuation of a point
light source with distance
The ColorSpace tool is a handy
tool that we can use to interactively add two colours together to see the
effects of the various strategies for handling oversaturated colours.
True
Which of the following
properties of Bezier curves guarantees that a line passes through the control
polygon as many times or more times than the line passes through the Bezier
curve itself?
Variation Diminishing
Parity is a concept used to
determine which _____________ lie within a polygon. (Choose best suitable
answer)
Pixels
The actual filling process in
boundary filling algorithm begins when a point _____________ of the figure is
selected.
Inside the boundary
Weiler-Atherton Polygon
Clipping technique modify the vertex-processing procedures for window
boundaries so that _________ polygons are displayed
Concave
If a line connecting any two
points within a polygon does not intersect any edge, then it will be a
_________ polygon.
Convex
__________ can be defined as a
mapping of point P(x, y, z) onto its image P`(x`, y`, z` ) in the view plane which constitutes the display surface.
Projection
Computer graphics and computer
vision are ________ disciplines.
Related
Interrelated
OpenGL has become the
industry's most widely used and supported ____________ graphics
application programming
interface (API), bringing thousands of applications to a wide variety of computer
platforms.
2-Dimensional and 3-Dimensional
____________ sets the reshape
callback for the current window.
glutReshapeFunc
X2/a2 – y2/b2 =1 is an equation of
Hyperbola
To modify the object shape,
shearing transformation can not be used.
True
Rotation is performed around a
fixed point called ______.
Pivot point rotation
Computer graphics is very
helpful in producing graphical representations for scientific
visualization and analysis
True
Save a line with both endpoints
inside all clipping boundaries.
Trivial Accept
Dark lights are nothing more
than lights in which one or more of the color values are _____.
Negative
A series of _______ computer
operations convert an object's three-dimensional coordinates to pixel positions
on the screen. Transformations, which are represented by matrix multiplication,
include modeling, viewing, and projection operations. Such operations include
rotation, translation, scaling, reflecting, orthographic projection, and
perspective projection.
Three
At a physical surface, our
eye's perception of the color depends on the distribution of photon energies
that arrive and trigger our _______ cells.
Cone
In the Phong Reflection model,
_______ light is the same everywhere.
Ambient
Aplane is two dimensional since
in order to uniquely define any point on its surface we require _______
numbers.
Two
In perspective projection, for
your view to come out correctly, you will also want the _______ to pass through
the middle of the screen.
Z axis
Neither floating-point nor
signed integer values are clamped to the range ________ before updating the
current color.
0, 1
Bezier curve is the ideal
standard for representing the ________ piecewise polynomial curves.
More complex
In the forms of texture
mapping, Image to world space and world space to image, each suffers from
different problems related to minification and magnification. Which of the two
shows the following problem: When the texture is larger than the screen space
it maps to, many texture units (texels) are never
sampled?
Image to world space
Both Boundary Filling and Flood
filling algorithms are non-recursive techniques,
False
The Phong reflection model
simplifies light-matter interactions into (essentially) 4 vectors and a number
of constants. Each piece of the Phong model uses different vectors and
constants. Which portion does NOT include taking a dot product?
Ambient
Consider the following problem from lighting: A point (P1) is at (0, 0, 0) with normal equal to 1/(2*sqrt(2))*(sqrt(2), 2, sqrt(2)). The light is located at (0, 1, 0). The viewer is located at (1, 1, 1). The specular and diffuse coefficients for the light are both (1, 1, 1), with the ambient portion as (.2, .2, .2). Complete the reflection vector. [ ------------] r = [ 0 ] [1/sqrt(2)] Choose from the values below:
1/sqrt(2)
The Phong reflection model simplifies light-matter interactions essentially into 4 vectors and a number of constants. Which piece of the Phong model is responsible for giving spheres their bright white spots?
Specular
We want our scene to look more realistic, we should use _________ lights.
Parallel
This is a simple example of line clipping: the display window is the canvas and also the default -- ------------------, thus all line segments inside the canvas are drawn
Clipping Rectangle
_________ One problem with Gouraud shading is that the ----------- intensities can never be greater than the intensities at the edges.
Triangles
There is more penetration of light in case of ___________ surfaces.
Nonconductor (like dielectrics)
Lights should be avoided because they are not for real time environment.
Spot
The physical range of colours a device can display is called _____________________ of the device.
Gamut
A polygon is usually defined by a sequence of vertices and ------------------
Edges
Which of the following affine transforms does NOT affect vectors?
Scale
______________ is simply the calculation of color reflected by the surface.
Shading
This projection technique has the direction of projection perpendicular to the viewing plane, and the viewing direction is perpendicular to one of the principle faces.
Orthographic Parallel Projection
When obtaining normal for a triangle, which of the following mathematical constructs is NOT used?
Vector dot products
Loosely, the alpha component of the RGBA quad represents the _______________of a surface.
Opaqueness
Which is the oldest in given types of the shading?
Flat Shading
The _______________ technique has the direction of projection perpendicular to the viewing plane, but the viewing direction is NOT perpendicular to one of the principle faces.
Axonometric Parallel Projection
The Color Space tool is a handy tool that we can use to interactively add two colours together to see the effects of the various strategies for handling oversaturated colours.
True
An algorithm that clips a polygon must deal with many ----------------- cases. The case is particularly noteworthy in that the concave polygon is clipped into ----------- isolate polygons.
Different, two
If we are not worried about computational resources, we should use _____________ lights.
Point
___________ lighting is not dependent on any source.
Ambient
In order to get a more realistic representation of lighting, we'll need to understand how light passes through a medium and how hitting the boundary layer at the ----------------- of two media can affect light's properties.
Intersection
Lambertian shading was used mostly back when computers weren't fast enough to do ________ in real time.
Gouraud shading
In Perspective Projection the point of View (POV) must lie on the ___________________.
Z axis
If we want any object to glow, we should use ________________ lights.
Emissive
An object's _______ determine its orientation relative to the light sources. For each vertex, OpenGL uses the assigned normal to determine how much light that particular vertex receives from each light source.
Normal
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