Angel and Shreiner: Interactive Computer Graphics, Seventh
Edition
Chapter 6 Odd Solutions
6.1 Point sources produce a very harsh lighting. Such images are
characterized by abrupt transitions between light and dark. The ambient
light in a real scene is dependent on both the lights on the scene and the
6.3 If we were to take into account a light source being obscured by an
object, we would have to have all polygons available so as to test for this
6.5 Materials absorb light from sources. Thus, a surface that appears red
under white light appears so because the surface absorbs all wavelengths of
6.7 Let ψbe the angle between the normal and the halfway vector, φbe
the angle between the viewer and the reflection angle, and θbe the angle
6.13 Without loss of generality, we can consider the problem in two
dimensions. Suppose that the first material has a velocity of light of v1and
the second material has a light velocity of v2. Furthermore, assume that
the axis y= 0 separates the two materials.
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6.19 Shading requires that when we transform normals and points, we
maintain the angle between them or equivalently have the dot product
6.21 Probably the easiest approach to this problem is to rotate the given
6.23 A global rendering approach would generate all shadows correctly. In
a global renderer, as each point is shaded, a calculation is done to see
which light sources shine on it. The projection approach assumes that we
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