Page 218 - DCAP504_Computer Graphics

Unit 13: Advanced Computer Graphics

13.6 Self Assessment

1. State whether the following statements are true or false:
(a) A bitmap is represented by ‘zeros’ and ‘ones’ of a rectangular array of points.
(b) Texturing can be either two-dimensional or three-dimensional.
(c) Physical textures depict variations on surfaces.
(d) Visual textures are created by repetitive use of shape and line.
(e) Forward mapping and reverse mapping are two methods of texturing.
(f) Unwrapping is similar to texture mapping.
(g) Cross-fading is the latest technique used in morphing.

2. Fill in the blanks:
(a) To unwrap the cuneiform tablets …………………. shading is employed.
(b) Pixels are made brighter and lighter by employing …………………. shading.
(c) Environmental mapping is also known as …………………. mapping.
(d) In ray tracing, rays are also traced ………………….
(e) 2-D and After Effects help to perform …………………. in a better manner.

3. Select a suitable choice for every question:
(a) Beier /Neely line-morphing method is used in which of the following mapping.
(i) Forward mapping
(ii) Reverse mapping
(iii) Vertex mapping
(iv) Texture mapping
(b) In vertex morphing, the target position is defined in separate meshes known as.

(i) Morph target
(ii) Texture
(iii) Physical texture
(iv) Warping
(c) Transformation of an image to a cartoon, relates to which of the following.
(i) Morphing

(ii) Texturing
(iii) Shading
(iv) Reflectance
13.7 Review Questions
1. Define texturing and discuss the physical and the visual textures.

2. Distinguish between texturing and unwrapping.
3. Photography was not adequate to visualize the cuneiform tablets. Justify
4. Ray tracing uses backward tracing of rays. Elaborate.
5. Cross-fading is taken over by computer graphics. Discuss.

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