Page 175 - DCAP504_Computer Graphics

Computer Graphics

2. Fill in the blanks:
(a) The …………………… or hidden surface algorithm determines the lines, edges, surfaces that
are visible or invisible to a viewer.

(b) A surface is considered visible if it has the ………………….Z value.
(c) At the end of the rendering process each scan line on screen is represented by a single entry
in the S-buffer which is called as the……………………….
(d) The ………………….. breaks up the scene into regions with the spatial relationship of these
regions built into the tree.
(e) The most important reason for using …………………. method is to create realistic renderings
of pictures with the help of laws of optics for reflecting and transmitting light rays.
3. Select a suitable option for every question:

(a) Which of the following is not an image space method?
(i) Back space
(ii) Area Subdivision
(iii) Z-Buffer
(iv) Scan Line
(b) Which of the following is a disadvantage of using Z-buffer algorithm?
(i) It can be used easily

(ii) It can be implemented easily in object or image space
(iii) It can be executed quickly, even with multiple polygons
(iv) It requires additional code to do transparent surfaces
(c) The Warnock algorithm uses ………………… for depth comparison.
(i) S-buffer
(ii) C-buffer

(iii) Z-buffer
(iv) Object space method
(d) The Scan line algorithm maintains the edge list in the………………………...
(i) Edge table
(ii) Depth tree
(iii) Octree
(iv) Scan line
(e) The Warnock algorithm is also known as the……………………..

(i) Painter’s algorithm
(ii) Area subdivision method
(iii) Ray tracing algorithm
(iv) Hiding

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