CS602 Quiz 3 fall 2024

 

Which is the oldest in given types of the shading?

a. Phong Shading

b. None of all

c. Gouraud Shading

d. Flat Shading           oky

2. One problem with Gouraud shading is that the ----------- intensities can never be greater than the intensities at the edges.

a. Square

b. Rectangle

c. Polygon

d. Triangle          oky

3. There is more penetration of light in case of ___________ surfaces.

a. None of the given

b. Both conductor and nonconductor

c. Nonconductor (like dielectrics)           oky

d. Conductor (like metals)

4. Length L depends on the angle alpha and the z coordinate of the point to be projected and L can be represented by --------------------.

a. z * 1/ tan (beta)

b. z * 1/ tan (alpha)           oky

c. z * L2

d. z * 1/ tan (gamma)

5. As f represents the attenuation of light, then f only approaches zero, when d approaches at distance -------------.

a. Zero

b. Infinity          oky

c. 1/2

d. 1/n

6. 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.

i. [ ------------]

r = [ 0 ]

ii. [1/sqrt(2)]

Choose from the values below:

b. 1

c. 0 (Not Confirm)            oky

d. 1/sqrt(2)

e. -1

7. 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.

a. Clipping Circle

b. Clipping Angle

c. Clipping Rectangle             oky

d. Clipping Polygon

8. Dark lights are nothing more than lights in which one or more of the color values are_______________.

a. Null

b. Negative           oky

c. Unknown

d. Positive

9. 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?

a. add none of the light from that light source to the object           oky

b. add only the ambient light from that light source to the object

c. add all components (i.e. ambient, diffuse and specular) from that light source to the object.

d. add all EXCEPT the ambient light from that light source to the object (i.e. diffuse and specular)

10. ___________ lighting is not dependent on any source.

a. Specular

b. Ambient

c. Diffuse

d. Emissive          oky

1). Which of the following is NOT a modern application for Computer Graphics-------------------         

• Stop-motion animation  
• Computer Aided Geometric Design        
• Video Games        
• Scientific Visualization      

2). Both Boundary Filling and Flood filling algorithms are non-recursive techniques,        

• False    
• True     

3). TV series are made as simply as possible from the animation point of view. This approach is generally known as ------------------------.         

• Full animation        
• Limited animation      
• Low animation        
• High resolution           

4). 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.        

• Two        
• One         
• Three        
• Four   

5). ----------- reflection is the effect of reflecting light toward the direction from which it came, no matter the orientation of the surface.         

• Forward scattering        
• Diffuse Lambertian        
• Backscattering        
• Retro   

6). What makes this really challenging to model is that the index of refraction for most materials is a function of the------------------- of the light. This means that not only is there a shift in the angle of refraction, but that the shift is different for differing ---------------of light.         

• Reflecting angle, Reflecting angle        
• Refracting angle, Refracting angle        
• Frequency, Frequency        
• Wavelength, Wavelength    

7). The reflected light wave turns out to be a ---------------------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). 

       

• Abnormal        
• Complex        
• Simple  
• Unknown      

8). Tessellation can be adaptive to the _______ degree of curvature of a surface.        

• Local
• Static        
• Global        
• Variable     

9). __________ sets the reshape callback for the current window. The reshape callback is triggered when a window is reshaped.         

• glutMainLoop        
• glutIdleFunc        
• glutReshapeFunc
• glutDisplayFunc      

10). 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        
• 0.0        
• 2.0        
• 1.0  

11). NURBS stands for-----------------------.         

• Non Universal Rational Binary Spline        
• Non Uniform Rational Binary Splines        
• Non Uniform Rational Beta Splines
• Non Universal Rational Beta Splines      

12). An orthogonal set of vectors--------------------------         

• Must be a set of linearly independent vectors        
• Must be a set of linearly dependent vectors        
• Must be made up of the basis vectors (e1, e2, and e3)      
• Can be made up of any set of vectors      

13). Bezier curve is numerically the ----------------------- of all the polynomial-based curves used in these applications.          

• None of the given        
• Most stable
• Less stable        
• Most unstable  

   

14). Bezier curve is the ideal standard for representing the ---------------------------- piecewise polynomial curves.        

• None of the given        
• Non complex        
• Most complex        
• More complex 

15). 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.         

• None of the given        
• Neither        
• Different        
• Same

16). The ---------------- is most simple example that exhibits the property self similarity.         

• Mosse        
• Fern    
• None of the given        
• Thohar      

17). 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.         

• Multi-dimensional        
• One-dimensional        
• Two-dimensional        
• Three-dimensional 

18). Which of the following properties of rational Bezier curves fails if the weight assigned to a control point is negative?          

• End-point interpolation        
• Variation Diminishing        
• Symmetry        
• Convex-Hull 

19). 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 size (in each dimension) which the light is assumed to have        
• The amount to perturb reflection vectors as they are mirrored across the normal        
• The material reaction to ambient, diffuse and specular light (respectively)      

20). 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 all components (i.e. ambient, diffuse and specular) from that light source to the object.        
• Add all EXCEPT the ambient light from that light source to the object (i.e. diffuse and specular)        
• Add only the ambient light from that light source to the object        
• Add none of the light from that light source to the object

21). 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.         

• False        
• True  

22). A polygon is usually defined by a sequence of ------------- and Edges.         

• Ending lines        
• Points        
• Vertices   
• Edges        

23). 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?         

• End-point interpolation        
• Variation Diminishing        
• Symmetry        
• Convex-Hull 

24). Parity is a concept used to determine which _____________ lie within a polygon. (Choose best suitable answer)         

• Edge         
• Vertices        
• Pixel   
• None of the given     

25). The actual filling process in boundary filling algorithm begins when a point _____________ of the figure is selected.         

• Outside the boundary        
• Inside the boundary 
• At boundary         
• None of the given      

26). Weiler-Atherton Polygon Clipping technique modifies the vertex-processing procedures for window boundaries so that _________ polygons are displayed correctly.        

• Convex        
• Concave      
• Complex        
• None of the given      

27). If a line connecting any two points within a polygon does not intersect any edge, then it will be a _________ polygon.        

• Convex
• Concave        
• Complex        
• None of the given      

28). __________ 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.         

• Mapping plane        
• Three Coordinate Planes        
• View plane        
• Projection 

29). 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).        

• Unknown        
• Simple   
• Complex        
• Abnormal 

30). Computer graphics and computer vision are ________ disciplines. 

• Related
• Interrelated 
• Same 
• Different 

31). 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 
• 3-Dimensional 
• 2-Dimensional and 3-Dimensional

32). -------- sets the global idle callback to be „func‟ so a GLUT program can perform background processing tasks or continuous animation when window system events are not being received. 

• glutIdle function
• glutKeyboardFunc 
• glutReshapeFunc 
• glutDisplayFunc 

33). X2/a2 – y2/b2 =1 is an equation of  _____

• Hyperbola    
• Parabola ( 4px=y2) 
• None of given 
• Ellipse (X2/a2 + y2/b2 =1) 

34). To modify the object shape, shearing transformation cannot be used. 

• False
• True  

35). Rotation is performed around a fixed point called ______. 

• Pivot point rotation
• Circular rotation
• Axis rotation 

36). Computer graphics is very helpful in producing graphical representations for scientific visualization and analysis 

• True
• False 

37). Save a line with both endpoints inside all clipping boundaries. 

• Trivial Reject 
• Trivial Accept
• None of given 

38). Dark lights are nothing more than lights in which one or more of the color values are _____. 

• Unknown 
• Negative 
• Positive 
• Zero 

39). 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
• Two 
• Four 
• Ten  

40). At a physical surface, our eye's perception of the color depends on the distribution of photon energies that arrive and trigger our _______ cells.   

• Eye 
• Retina 
• Cone   

41). This projection technique has the direction of projection perpendicular to the viewing plane, but the viewing direction is NOT perpendicular to one of the principle faces.   

• Orthographic Parallel Projection 
• Axonometric Parallel Projection
• Oblique Parallel Projection 

42). In the Phong Reflection model, _______ light is the same everywhere.   

• Ambient 
• Diffuse 
• Specular 
• Emissive 

43). A plane is two dimensional since in order to uniquely define any point on its surface we require _______ numbers.   

• Two
• Three 
• Four 
• Five 

44). In perspective projection, for your view to come out correctly, you will also want the _______ to pass through the middle of the screen.   

• X axis 
• Y axis 
• Z axis
• None 

45). Neither floating-point nor signed integer values are clamped to the range ________ before updating the current color.   

• 0 ,  -1.0 
• -1 , 1 
• 1 , -1 
• 0, 1

 
46). 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. 

• Unit  
• Normal
• None of given 

47). Which was the oldest shading model? 

• Flat Shading
• Phong Shading 
• Gouraud Shading 

48). Which of the following affine transforms does NOT affect vectors? 

• Scale 
• Rotation 
• Shear 
• Translation

49). If solving for inside-outside of a triangle using barycentric coordinates, and you have two barycentric coordinates solved (bc1 = .57, bc2 = .62) which of the following do you know?  

• The point is outside the triangle 
• The point is on the boundary of the triangle 
• The point is inside the triangle 
• The hit point is on the “back face” of the triangle  

50). The majority of the execution time of a ray tracer is spent in ray-object intersection code.  

• True 
• False 

51). Snell‟s law is used to calculate which one of the following rays?  

• Start rays 
• Shadow rays 
• Reflection rays 
• Transmission rays 

52). You might as well recurse on reflection and transmission rays until you hit nothing. This always is bound to happen.   

• True 
• False   

53). In the Pixar short “Geri‟s Game”, the character Geri was created using which of the following techniques?  

• Fractals 
• Bump mapping 
• Environment mapping 
• Catmull-Clark Subdivision Surfaces 

54). In the Pixar short “Geri‟s Game”, the trees in the background were created using which of the following techniques?  

• Fractals 
• Bump mapping 
• Environment mapping 
• Catmull-Clark Subdivision Surfaces 

55). The basic functions fi(u) in Bezier curve must be symmetric with respect to u and (u-2)  

• Yes 
• No

56). In the Pixar short “Geri‟s Game”, Geri‟s glasses seemed to bend the light as it passed through. Which of the following techniques was used?  

• Fractals 
• Bump mapping 
• Environment mapping 
• Catmull-Clark Subdivision Surfaces 

57). A polygon is usually defined by a sequence of vertices and ------------------  

• Edges
• Vertices
• Points Ending lines 

58). Gouraud shading is the current de jure shading standard in accelerated ------------ hardware.  

• 2Dimensional 
• 3Dimensional
• Multidimensional 
• None 

59). _________ is based on characteristic size or scale    

• Fractal Geometry (Fractal shapes are self similar and independent of size or scaling) 
• Traditional Geometry 
• Euclidean Geometry (Euclidean shapes normally have a few characteristic sizes or length scales)
• None of Above 

60). Arrange the scene to be photographed into the desired composition   

• Projection transformation 
• Viewport transformation 
• Modeling transformation
• Viewing transformation   

61). Which language API defines graphics operations independent of the operating system or computer hardware? Additional hardware specific libraries are used to provide an interface between API and the hardware and between the user and the platform specific windowing system.  

• DirectX 
• Graphix Windowing Toolkit 
• CGI 
• OpenGL

62). When transforming a random Axis-Aligned Bounding Box defined by the points (nearx, neary, nearz) and (farx, fary, farz) to the standard orthographic viewing box, which affine transforms are used?   

• Shear and translation 
• Rotation and scale 
• Scale and shear 
• Translation and scale  

63).We want our scene to look more realistic, we should use _________ lights.  

• Ambient
• Point 
• Parallel 
• Spot 
• None of the given  

64). 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
• Clipping Circle 
• Clipping Polygon 
• Clipping Angle  

65). One problem with Gouraud shading is that the ----------- intensities can never be greater than the intensities at the edges.   

• Triangles
• Squares 
• Rectangles
• Polygons  

66). There is more penetration of light in case of ___________ surfaces.   

• Conductor (like metals)  
• Nonconductor (like dielectrics)    
• Both conductor and nonconductor 
• None of the given 

   
67) _________ lights should be avoided because they are not for real time environment.   

• Point 
• Parallel 
• Spot
• None of the given  

68). The physical range of colors a device can display is called _____________________ of the device.   

• Sharpness 
• Gamut
• Coloring
• Coloring with Sharpness    

69). ______________ is simply the calculation of color reflected by the surface.   

• Shading
• Clamping 
• Scaling 
• None of the given   

70). When obtaining normals for a triangle, which of the following mathematical constructs is NOT used?   

• Vector normalization 
• Vector cross products  
• Vector dot products 
• Point-Point subtraction  

71). Loosely, the alpha component of the RGBA quad represents the _______________of a surface.   

• Opaqueness
• Light 
• Darkness 
• Shine     

72). An algorithm that clips a polygon must deal with many ----------------- cases. The case is particularly note worthy in that the concave polygon is clipped into ----------- isolate polygons.   

• Similar, three  
• Different, two
• Different, three 
• Similar, two

73). ___________ lighting is not dependent on any source.   

• Ambient
• Diffuse 
• Specular 
• Emissive 

74). 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
• Union 
• Endpoints 
• Edges  

75). Lambertian shading was used mostly back when computers weren't fast enough to do ________ in real time.   

• Phong shading 
• Processing Shading  
• Gouraud shading

76). In Perspective Projection the point of View (POV) must lie on the ___________________.    

• All axis  
• Z axis
• X axis 
• Y axis 

77). If we want any object to glow, we should use ________________ lights.   

• Ambient 
• Diffuse 
• Specular 
• Emissive

78). There are not many different ways of representing the intensity of a particular color element. 

• True  
• False

79). In Perspective Projection the screen plane must be parallel to the__________________.   

• Y-Z plane 
• X-Y plane
• Z-Y plane 
• X-Z plane 

80). ___________ light is reflected in all directions from surface.  

• Ambient  
• Diffuse
• Specular 
• Emissive 

  
81). A space curve can be confined to a plane.   

• Yes  
• No

82). 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 = -------------   

• UP  
• NP
• UN 
• None

83). Perspective projection is specified with the function glFrustum().  

• Yes
• No  

84). Using a lighting model based upon the Blinn Phong model means that we'll always get a uniform specular highlight based upon the color of the --------------- light and material, which means that all reflections based on this model, will be reminiscent of plastic.   

• Union  
• Refracting 
• Intersection 
• Reflecting

85). Refractive index is a function of temperature, mostly due to density changes in materials with changes in temperature.    

• True
• False    

86). 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)
• z * L2 z * 1/ tan (beta) 
• z * 1/ tan (gamma)    

87). The traditional approach in real-time computer graphics has been to calculate lighting at a vertex as a sum of the ________ light.   

• Ambient  
• Ambient, diffuse, and specular
• Specular Diffuse, and specular 

88). Another way to define a space curve by using intermediate points and the tangents at each end for making the curve   

• Yes  
• No

89). 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.

• Tertiary Binary 
• Single platform  
• Multiplatform

90). glutReshapeWindow 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.   

• Neutral 
• Negative  
• Positive
• None of the given 

91). 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 ----------------------.   

• Binary polynomials 
• Mono polynomials 
• Quadratic polynomials  
• Cubic polynomials

92). 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
• Pressure 
• Nature 
• Volume   

93). 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. 

• Isolate 
• Different  
• Same
• None   

94). The attenuation formula is f =------------------------, where C, L and Q are the constant, linear and quadratic attenuation factors and d is the distance between the vertex being lit and the light source.  

• 1/(C + Ld + Qd2)
• 1/(C + Ld + Qd) 
• 1/(C + L +d + Qd2) 
• 1/(Cd + Ld + Qd2) 

95). Bezier curve is tangent to the lines connecting _____________.   

• First two points 
• Last two points  
• Fist two points and last two point
• None of the given 

96). 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.   

• Six 
• Three 
• Two 
• Nine

97). Choose a camera lens or adjust the zoom  

• Projection transformation
• Viewport transformation 
• modeling transformation 
• Viewing transformation 

98). _________ OpenGL function is used for aiming and positioning the camera towards the object   

• gluLookAt() 
• glLoadIdentity()
• glFrustum() 
• None of Above   

99). A parametric curve is one whose defining equations are given in terms of a -------------, common, independent variable called the parametric variable.   

• Triple 
• Double 
• Single (Page 325) 
• None of the given   

100). The reflection coefficients are in the ------------------------- range and are specified as part of the material property. However, they are strictly empirical and since they simply adjust the overall intensity of the material color, the material color values are usually adjusted so the color intensity varies rather than using a reflection coefficient.   

• [0, 10]  
• [0, 1]
• [0, 5] 
• [0, 2]