COS3712 Oct/Nov Exam 2023

COS3712 Oct 2022 Exam Computer Graphics (University of South Africa) lOMoARcPSD| Question 1 Complete Marked out of 2.00 In which pipeline approach are vertices defined by a program and flow through a sequence of modules that transforms them, colors them, and determines where they are visible etc. The output is the pixels in a frame buffer. a. Object oriented b. Z buffer c. Image orientated. d. Painters or depthsort method Question 2 Complete Marked out of 2.00 Flag question Question text Which of the following is not an affine transformation? a. A combination of translation and scaling. b. A combination of scaling and shearing. c. A combination of rotation and translation, d. A combination of rotation and projection Question 3 lOMoARcPSD| Complete Marked out of 2.00 Flag question Question text In the Cohen-Sutherland line clipping algorithm an outcode can have _____ bits for twodimensional clipping and _____ bits for three-dimensional clipping. a. 4,6 b. 6,8 c. 1,3 d. 2,4 Question 4 Complete Marked out of 2.00 Flag question Question text (True or False)You get the same effect if the order of transformations that comprise an instance transformation was changed. a. True, the class of objects will remain the same, and the degrees of freedom of the objects we produce will be the same. b. False, although we will have the same number of degrees of freedom in the objects we produce, the class of objects will be very different. c. lOMoARcPSD| False, although the class of objects will always remain the same, the degrees of freedom in the objects we produce will always be different. d. True, although we will not have the same number of degrees of freedom in the objects we produce, the class of objects will be the same. Question 5 Complete Marked out of 2.00 Flag question Question text In the Cohen-Sutherland line clipping algorithm if the logical ______of the endpoint codes is ______, the line can be trivially accepted. a. OR, zero b. AND, zero c. OR, NOT zero d. AND, NOT zero Question 6 Complete Marked out of 2.00 Flag question Question text Which of the following is not an advantage of using the pipeline approach in computer graphics. a. It is an efficient method of processing primitives. lOMoARcPSD| b. Memory requirements are reduced because we need not keep all objects available at all times. c. Blending can be handled in a physically correct manner. d. Each primitive can be processed independently Question 7 Complete Marked out of 2.00 Flag question Question text a. False because, although Bresenhams algorithm avoids all floating point calculations, these calculations are required for each pixel generated, hence it is more efficient than the DDA algorithm. Question 8 Complete Marked out of 2.00 Flag question Question text What does the following matrix represent? 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 3 Downloaded by Genial Adventures () lOMoARcPSD| a. Uniform scaling b. Non-uniform scaling c. Identity matrix (no effect) d. Reflection Question 9 Complete Marked out of 2.00 Flag question Question text (True or False) Immediate mode requires more processing power than retained mode. a. True, because in immediate mode we have the overhead of sending small amounts of data to the graphics processor for each vertex we generate. b. False, because in retained mode we have the overhead of sending small amounts of data to the graphics processor for each vertex we generate. c. False, if in immediate mode if we want to redisplay the scene, we do not have to go through the entire creation and display process again d. True, if in retained if we want to redisplay the scene, we do not have to go through the entire creation and display process again Question 10 Complete Marked out of 2.00 lOMoARcPSD| Flag question Question text Which of the following regarding projection normalization is false. a. Projection normalization occurs in the geometric processing phase of the graphics pipeline. b. The normalization process allows us to carry parallel and perspective projections with alternate pipelines. c. Projection normalization distorts the objects such that the orthogonal projection of the distorted objects is the same as the desired projection of the original objects. d. Projection normalization ensures that all projections can be converted to orthogonal projections Question 11 Complete Marked out of 2.00 Flag question Question text Which of the following about the z-buffer algorithm is false? a. Its complexity is inversely proportional to the number of fragments generated by the rasterizer b. It can be implemented with a small number of additional calculations over what we have to do to project and display polygons without hidden-surface removal. c. Downloaded by Genial Adventures () lOMoARcPSD| The z-buffer forms part of the frame buffer and has the same spatial resolution as the colour buffer. d. The z-buffer algorithm is an image-space algorithm that fits in well with the rendering pipeline. Question 12 Complete Marked out of 2.00 Flag question Question text Which anti-aliasing strategies results in smoother texturing? a. Smoothing b. Over sampling c. Linear filtering d. Point sampling Question 13 Complete Marked out of 2.00 Flag question Question text Which of the following pipeline approaches loop over pixels, or rows of pixels called scanlines. For each pixel we are working backwards to determine which geometric primitives can contribute to its colour. a. Image orientated. lOMoARcPSD| b. Object oriented c. Painters or depthsort method d. Z buffer Question 14 Complete Marked out of 2.00 Flag question Question text In the Phong model the formula for the ambient term is kaIa? We will make a surface darker by ... a. decreasing ka b. decreasing Ia and decreasing ka c. increasing Ia and decreasing ka d. inceasing ka Question 15 Complete Marked out of 2.00 Flag question Question text Which of the following transformations scale orient and translates an object to the desired location in the scene? Downloaded by Genial Adventures () lOMoARcPSD| a. Instance b. Projection c. View d. Modelling Question 16 Complete Marked out of 2.00 Flag question Question text A__________associates a texel with each point on a geometric object that is itself mapped to screen coordinates. a. Texture image array b. Texture map c. Texel map d. Texel array Question 17 Complete Marked out of 2.00 Flag question lOMoARcPSD| Question text When using flat shading our eyes notices small differences in shading between polygons, this is due to the property of the human visual system known as ______. a. Mach bands b. Lateral inhibition c. Fractal distancing d. Optic bands Question 18 Complete Marked out of 2.00 Flag question Question text Consider a line segment (in 3 dimensions) with endpoints a and b at (0, 1, 0) and (1, 2, 3) respectively. What would the coordinates of vertex a be after performing a translation of 2 units along the y axis. a. (0, 3, 0) b. (3, 1, 0) c. (0, 1, 0) d. (3, 4, 3) Question 19 Complete Marked out of 2.00 Downloaded by Genial Adventures () lOMoARcPSD| Flag question Question text What does the following matrix represent ? 0 -1 0 0 0 0 -1 0 -1 0 0 0 0 0 0 1 a. Rotation b. Non-uniform scaling E c. Perspective projection d. Reflection Question 20 Complete Marked out of 2.00 Flag question Question text In which of the 4 major stages of a graphics pipeline would linear filtering normally occur? a. Geometry processing lOMoARcPSD| b. Fragment processing c. Rasterization d. Modelling Question 21 Complete Marked out of 2.00 Flag question Question text An affine space is an extension of the vector space that includes an additional type of object: a. the point b. the scalar field. c. the scalar vector d. the normal Question 22 Complete Marked out of 2.00