Nonphotorealistic computer graphics offers a fascinating field of new visual imagery that can be rendered via the computer. If we view the photorealistic rendering as only one part of the whole field of rendering, then only very little research with regards to the wide range of possible forms of expression has been provided to date. For the future, this area offers an enormous field for

2Generally it is difficult to estimate the number of lines beforehand, though the algorithm can handle an over-estimated number of lines.

researchers with regard to the further development of existing applications as well as fundamental questions for improvement.

Подпись: Section 11.5 RESUME Thus, cognition-psychological aspects might become important in that the ques­tion is asked why line drawings are interpreted by our visual system as repre­sentations for images of real objects. This may be caused by the fact that the human brain on one level of its image processing uses a line representation that is here addressed directly through graphics. In this context, also the ques­tion arises what kind of images are especially well accepted. With answers to these questions, criteria for a taxonomy of nonphotorealistic renditions can be established. Also, the approach triggers the already-addressed question, what actually produces our perception of “realism”. Aside from issues addressed the in Sect. 9.10, there is certainly much more to discover that would possibly help us to overall improve the methods now available in computer graphics.

Finally, some words with regard to the tension between technology and art should be added. Computer graphics does not aim to make the artist super­fluous. Excellent artistic illustrations are always the result of a creative process that cannot be replicated using computers. Computer graphics aims more at au­tomating drawing techniques in order to simplify routinely exercised tasks. For example, computer-generated drawings would allow for an illustrator to avoid having to produce several hundred images of the same object with slightly modified positions when creating an animation. If a user can take a virtual walk through an illustrated world, then this enables new artistic creations in design that would not be possible without computer graphics.

In the context of interactive programs new possibilities emerge for artistic in­stallations. Computers can be programmed to react in new ways to the inputs of the user, and hence can help to discover new aesthetic worlds as well as transport content with high complexity. But, whether here new aspects with respect to design qualities are achieved must be assessed in close collaboration with the art community. On the other hand, in the next chapter we will describe some of the work of artists who have already gone down this line and who were an inspiration for us to create programs for generating organics and plants.