Non-photorealistic rendering (NPR) techniques vary greatly in their
level of abstraction. In technical illustrations, shape information
is valued above realism and aesthetics. Therefore a high level of
abstraction, like the images in Figure 2.1, would be
inappropriate. As summarized in Table 2.1, no work
has been done which uses the ideas and techniques of technical
illustrators to generate not only 2D technical illustrations but also
to provide an interactive environment for viewing 3D models as 3D
technical illustrations. A review of the papers involving NPR or other
illustration techniques used in computer graphics reveals that most
papers can be partitioned into two categories: those which generate
only aesthetic images and those whose purpose is to convey shape and
structure. The images in the latter category may themselves be
aesthetically pleasing, but this is a side effect rather than a
primary goal. These papers can also be further divided into those
that generate a single image and those that are part of an interactive
or animation system. Human perception and recognition
studies [2,4,7] are another valuable source of
information. These perception studies suggest an explanation of why
line drawings, like technical illustrations, are enough for object
recognition and provide a hint as to why they may also provide shape
information.
Table 2.1:
Summary of non-photorealistic and other computer graphics
papers.
