Dynamic Illustration Principles

  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.