Introduction to Computer Graphics

Q1: Explain projection and differentiate parallel and perspective projections.

Q2: Explain Depth-Buffer Method in detail.

Q3: Write steps required to draw a line from point (x,y) to (x’,y’) using Bresenham’s line drawing algorithm.

Q4: How do I perform basic viewing in 3D?

Q5: How do I rotate a 2D point?

Q6: How do I do a hidden surface test (backface culling) with 2D points?

Q7: Describe clipping with its applications.

Q8: Give difference between Vector scan display and Raster scan display method.

Case Study

1. Develop the transformation for finding the reflection point w.r.t. the line ax+by+c=0

2. Explain with examples the operation o segments.

3. The pyramid is defined by the coordinates A(0,0,0), B(1,0,0),C(0,1,0) and D(0,0,1) is rotated 90 degrees about the line L that has direction vector V= i +j +k and passing through the origin. Find the co-ordinates of rotated figure

Assignment – C

Q1: Which kind of models are made up only of quad polygons?

a) multidimensional surface

b) extrovert surface

c) subdivision surface

d) introvert surface

Q2: A spline is a type of:

a) line

b) angle

c) curve

d) all of the above

Q3: Which kind of models are made up of points, lines and faces?

a) geometry surface

b) polygonal

c) introvert surface

d) subdivision surface

Q4: A transparency map is used to:

a) to get bush out of office

b) cover the object so you can’t see it

c) All of the above

d) None of the above

Q5: Output, which is made up of pictures, sounds, and video, is called.

a) COM

b) Hard copy

c) Graphics

d) Multimedia

Q6: In ”Utah” graphics, lights are simplified in order to approximate light/matter interaction with a minimum amount of work. Which of the following is NOT true about the simplifications made in “Utah” graphics lights?

a) Light intensity and color are folded into one value.

b) Lights are assumed to have zero size

c) Spotlights can not be handled

d) Soft shadows can not be handled

Q7: 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?

a) Ambient

b) Diffuse

c) Specular

d) All of the above

Q8: The Phong reflection model simplifies light-matter interactions into (essentially) 4 vectors and a number of constants. Which piece of the Phong model is responsible for giving spheres their bright white spots?

a) Ambient

b) Diffuse

c) Specular

d) All of the above

Q9: The Phong reflection model simplifies light-matter interactions into (essentially) 4 vectors and a number of constants. Which of the following is NOT a vector needed for the Phong reflection model?

a) Surface Normal

b) Direction to Viewer

c) Direction to Material Center

d) Direction to Light

Q10: In the Phong Reflection model, ambient light is the same everywhere.

a) true

b) false

c) All of the above

d) None of the above

Q11: Which of the following is NOT true about quaternions?

a) They are made up of 4 numbers

b) They should always be normalized to length 1

c) They can be used to represent all affine transforms

d) They can be used to define the rotation of an object.

Q12: Which of the following does NOT figure into the Field of View of a pinhole camera?

a) The direction of projection

b) The distance from the center of projection to the projection plane

c) The size of the projection plane

d) All of the above

Q13: 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.

a) Orthographic Parallel Projection

b) Axonometric Parallel Projection

c) Oblique Parallel Projection

d) All of the above

Q14: This projection technique does NOT have the direction of projection perpendicular to the viewing plane.

a) Orthographic Parallel Projection

b) Axonometric Parallel Projection

c) Oblique Parallel Projection

d) All of the above

Q15: 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.

a) Orthographic Parallel Projection

b) Axonometric Parallel Projection

c) Oblique Parallel Projection

d) All of the above

Q16: 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?

a) shear and translation

b) rotation and scale

c) scale and shear

d) translation and scale

Q17: In class, we discussed how the image of the Double Eagle Tanker was obtained for the large poster in the main hall of Sitterson. It required rendering several perspective images using OpenGL. Which of the following was NOT a step required in that process?

a) handling projection planes non-orthogonal to the viewing direction

b) cutting a single projection plane into many separate projection planes

c) rotating the viewing direction to be the same as the .z direction

d) handling several different centers of projection

Q18: In OpenGL, there are several different matrices. We have discussed two of them in class. Which one of the below would be used in conjunction with a glRotatef function call?

a) GL_MODELVIEW

b) GL_PROJECTION

c) All of the above

d) None of the above

Q19: In OpenGL, there are several different matrices. We have discussed two of them in class.

Which one of the below would be used in conjunction with glFrustum?

a) GL_MODELVIEW

b) GL_PROJECTION

c) All of the above

d) None of the above

Q20: Which of the following is the order that geometry operations are performed in OpenGL (where we read the order from left to right)?

a) GL_PROJECTION GL_MODELVIEW Perspective division

b) GL_MODELVIEW GL_PROJECTION Perspective division

c) Perspective division GL_PROJECTION GL_MODELVIEW

d) GL_MODELVIEW Perspective division GL_PROJECTION

Q21: Bitmap graphics is–

a) Resolution independent

b) Graphical dependent

c) Resolution dependent

d) Graphical independent

Q22: What is another name for bitmap graphics?

a) Bitmap graphics

b) Raster graphics

c) Jpeg graphics

d) png graphics

Q23: What is another name for vector graphics?

a) Spline

b) Splines

c) Raster

d) Vector

Q24: Vector graphics are–

a) Jpeg

b) Bitmap

c) Resolution dependent

d) Resolution independent

Q25: Which of the following is a common size for digital video?

a) 720 pixels x 480 pixels

b) 800 pixels x 600 pixels

c) 1020 pixels x 480 pixels

d) 400 pixels x 300 pixels

Q26: What is the RGB equivalent of the color red?

a) 0, 255, 0

b) 255, 0, 0

c) 255, 255, 0

d) 0, 0, 0

Q27: An alpha channel determines:

a) the viability of a bitmap image

b) the transparency of a bitmap image

c) the opacity of a bitmap image

d) none of the above

Q28: Standard 35mm film runs at what frame rate?

a) 24 fps

b) 35 fps

c) 29 fps

d) 12 fps

Q29: After Effects, position, rotation, opacity and scale are examples of what?

a) keyframe channel

b) rotation channels

c) animation channels

d) opacity channels

Q30: Which is an example of rendering?

a) rendering

b) taking all of the changes and showing them in a visible image

c) taking all of the calculations from a program to make an image

d) all of the above

Q31: Which of the following is a method of compressing a movie?

a) MPEG

b) MOV

c) encoding

d) compressing

e) All

Q32: Which kind of models are resolution independent?

a) z-axis

b) NURBS

c) polygonal

d) tesselation

Q33: The 3D Cartesian coordinate system adds which axis to the 2D axes?

a) z-axis

b) y-axis

c) x-axis

d) c-axis

Q34: The 3D Cartesian coordinate system adds which axis to the 2D axes?

a) z-axis

b) y-axis

c) x-axis

d) c-axis

Q35: Where do all three axes meet?

a) side

b) bottom

c) top

d) origin

Q36: 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?

a) The material reaction to ambient, diffuse and specular light (respectively)

b) The amount to perturb reflection vectors as they are mirrored across the normal

c) The size (in each dimension) which the light is assumed to have

d) The attenuation of a point light source with distance

Q37: When obtaining normals for a triangle, which of the following mathematical constructs is NOT used?

a) Point-Point subtraction

b) Vector dot products

c) Vector cross products

d) Vector normalization

Q38: A touch screen is recommended for

a) pressure-sensitive drawing and painting

b) projects that track users

c) program involving public input and simple tasks

d) day-to-day computer work

Q39: The transformation wherein the object is first rotated about x-axis and then about y-axis is

a) instant

b) rotation

c) shearing

d) tilting

Q40: The sizes of graphics files for use on the web are reduced using

a) Compression

b) Depression

c) Impression

d) Compilation