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Up: A Non-Photorealistic Lighting Model
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All of the characteristics from Section 3 can be
automated in a straightforward manner. Edge lines are drawn in black, and
highlights are drawn using the traditional exponential term from the
Phong lighting model [17]. In Section 4.1,
we consider matte objects and present reasons why traditional shading
techniques are insufficient for technical illustration. We then
describe a low dynamic range artistic tone algorithm in
Section 4.2. Next we provide an alogrithm to approximate
the anisotropic appearance of metal objects, described in
Section 4.3. We provide approximations to these
algorithms using traditional Phong shading in
Section 4.4.
Bruce or Amy Gooch
4/21/1998