Next: Viewer Versus Object Motion
Up: Interactive Technical Illustration
The question remains, how do the 2D illustration rules change
for an interactive 3D technical illustration? Adapting the shading
and line conventions presented earlier is fairly straightforward as
long as the line weight conventions have frame-to-frame coherence.
The more interesting issues depend upon changing the viewer's position
versus moving the object. Since there are no relevant protocols in
traditional illustration, we may want to base these 3D illustration
conventions on how one would move real objects. This has an effect on
how the light changes with respect to the object, the light position
can be specified as relative to the object or to the viewer.