The interactive installation “Galapagos” was commissioned by the ICC (InterCommunication Center) in Tokyo, and exhibited there from 1997 to 2000. The visitor was positioned before 12 monitors arranged in a circular arc on pedestals showing amoebas or anemons, which reminded one of organic forms (Fig. 12.8). On the floor before each pedestal with a monitor, there was a touch- sensitive mat. If the visitor stepped onto one of the mats, all forms disappeared except the one selected by the visitor, and shortly thereafter forms appear that are similar to the selected one. The visitor thus selected the forms that were most interesting, and the associated genome was distributed to the 11 other computers and there it was mutated.
The structure and interaction resembled the installation “Gene... >
In 1994 Sims showed “Evolved Virtual Creatures” a video animation in which simple block structures in a virtual environment move around in a partially bizarre way. The movements were not programmed or produced using techniques such as key framing, but originated from a virtual motoric of the block structures coupled with a sensor system, which had developed over hundreds of steps – the objects had learned to move themselves. Here, visible in the sophisticated dynamics, a strong interest in the computer-aided simulation of movement can be recognized. While in Panspermia evolutionary techniques were applied only to the morphology of the plants, Sims now turned to the evolution of movement.
Evolved creatures in competition for a green block. (Courtesy of Karl Sims)
Panspermia, from 1990, visualizes the theory that life in the universe exists in the form of seeds and spreads spores. The two-minute computer animation begins with a grain flying through the universe, which hits a planet and bursts. From the spores scattered into the surrounding field different plants evolve. In the animation sequences that follow individual species grow: ferns, winding plants and trees. In one sequence, the camera drives through a forest with diverse plants (see Fig. 12.3). The animation ends with individual plants forming seeds, which they shoot out into space: the cycle of life.
Sims used procedural models for the production of the plants: 21 parameters affect the condition and growth of a three-dimensional hierarchical structure of connected segments... >
Karl Sims is referred to as one of the pioneers of evolutionary computing. He became known through his video animation “Panspermia” from 1990, his innovative and still-impressing work “Genetic Images” from 1993, and “Evolved Virtual Creatures” (1994), for which he had already described the basic structures in 1991 . In 1997, he presented another aesthetic conversion of
Chapter 12 the interaction principle of “Genetic Images” at ICC, the Intercommunication Media Art Center in Tokyo, with the installation “Galapagos”.
Karl Sims does not really see himself as an artist or a scientist, but rather as a researcher in both disciplines... >
William Latham studied art at Christ Church, Oxford, and print media at the Royal College of Art in London. Between 1987 and 1994 he worked as a “visiting artist” at the iBM UK Scientific Centre in Winchester, where together with the mathematician Stephen Todd he developed his artistic style.
The works evolved during this time form the basis for an aesthetic that is known today as “Organic Art”, which serves as a model to many artistic artworks. Characteristic of his style are repetitive structures, in which simple geometrical primitives such as balls or tori are repeatedly joined, and, by iteration of geometrical transformations, such as rotations or translations, generate complex organic-appearing structures... >
Growing Plants and Evolved Organics
In this last chapter we would like to treat a topic that substantially contributed to the development of this book: plants and organics in media art. With digital media the border between art and science is more and more indistinguishable. Artists develop solutions that contribute to the scientific discussion, they anticipate developments or take them up again in another context, they publish in scientific magazines, and merge their work with that of conventional scientists in research institutes.
In the following we want to present some exemplary work that appears especially interesting within the context of our conception of nature and its replication via the computer: Karl Sims, for example, uses evolutionary strategies for plant modeling in the a... >
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.
Thus, cognition-psychological aspects might become important in that the question is asked why line drawings are interpreted by our visual syste... >
Half-toning algorithms on the basis of cross-hatching control the grayscale values of an image either through variation of the line density or line thickness. The variation of the line density was already discussed above for short lines. Examples for the variation of the line thickness can be found in . For the intersection lines, also this approach is selected, because only a fixed number of lines are available, and varying the thickness is more suitable for long crosshatching lines. Examples from the arts, such as copperplates or other engraving techniques, demonstrate this.
Each cross-hatching line has to represent through its own grayscale value the overall grayscale value of an area on the object surface
To determine each line thickness, around each line an area ... >
Halftoning procedures also offer the option of generating a cross-hatching with short lines on the surface. Here the standard algorithms are modified: instead of generating points, now lines are created. In  this is realized through a modification of the classical Floyd-Steinberg algorithm . Usually the algorithm scans the image per line from top to bottom, sets black and white pixels into the image to be produced, and measures the grayscale value error that hereby occurs. This error is then distributed to the neighboring pixels.
A modified procedure for lines uses another error term. Unfortunately, only short lines can be used, since the Floyd-Steinberg algorithm is a locally working method that consequently produces larger errors when working with long lines... >
cross-hatchings usually serve the rendering of lighting effects in illustrations. They are applied to those regions that lie in the shadow, and in contrast to adding details they permit an additional blackening that has a more two-dimensional effect. Hence, they are rather used for smooth surfaces such as the trunks and branches (compare Fig. 11.8). However, in the lower part of Fig. 11.6, cross-hatching can also be seen in the foliage.
Methods for the automatic rendering of cross-hatching again must include algorithmic approaches. At the beginning of the chapter, we addressed the method of Salisbury, Winkenbach and Salesin, who solved this problem with special stroke textures that display cross-hatching... >