Deussen / Lintermann Digital Design of Nature
1. Auflage 2005
ISBN: 978-3-540-27104-8
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark
Computer Generated Plants and Organics
E-Book, Englisch, 297 Seiten, eBook
Reihe: X.media.publishing
ISBN: 978-3-540-27104-8
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark
Zielgruppe
Professional/practitioner
Weitere Infos & Material
Computer-Generated Plants - Introduction.- Plants - Botanical Description.- Some Mathematics.- Plants as Mathematical Objects.- Procedural Modeling - Programming of Plants.- Rule-Based Modeling - Single Plants are 'Emerging'.- Rule-Based Object Production - Interactive Modeling.- Modeling Terrain - The Basis.- Modeling Vegetation - A Landscape Evolves.- Rendering - Creating 'Virtual Reality'.- Level-of-Detail - Fast Rendering of Images.- Landscape Sketches - Artistic Renditions.- Media Art - Growing Plants and Evolved Organics.- Practical Plant Modeling - Using Xfrog.- Glossary.- Figures.- Bibliography.- Index
11 Landscape Sketches (p. 201-202)
Artistic Renditions
In contrast to photorealistic landscape images, the rendering of synthetic plant and landscape sketches has undergone little research so far. However, the already- addressed areas of application in architecture and landscaping require this kind of rendering. Currently, prefabricated images, which are combined via computer, most often must suffice. In addition, there are several collections of images [58] that incorporate lots of plant images in different styles and scales. These images can be copied and added to the drawings.
Aside from the enormous manual effort that is needed to combine the images, this method, of course, is only applicable for single images. New media, however, permit entirely new forms of presentation. The user should be able to analyze planned buildings virtually, to see them in different views, and to modify the corresponding scenes interactively. This is not possible using traditional plant images as part of a series. Digital plant models and drawings are required, which can be turned and moved and thereby reflect a spatial coherence. Since this kind of modeling is also useful in areas outside of architecture and landscaping, such as biology, botany and education, developing the proper methods and tools is a worthwhile undertaking that reaches far beyond the rendering of plants.
In this chapter we will introduce different approaches for the production of plant images in the style of hand-drawn artworks. After a short introduction into the area of nonphotorealistic rendering (NPR), traditional drawing styles used by artists will be examined with regard to their algorithmic implementation. It has become evident that some drawing styles are replicated satisfactorily via the computer, while others cannot be simulated. In a new method, some of the traditional techniques are imitated, and sample plants are produced in various drawing styles. Sample animations can be found on the accompanying website that prove that models generated in this way have the required spatial coherence, i.e., they can be turned and scaled without interfering flickering effects.
An important aspect when drawing trees is the rendering of the trunk and the branches. Here the methods differ from those used for the leaves, since we are dealing with a totally different form of geometry. In particular, the production of cross-hatchings on the trunk and branches is an interesting problem that is, however, partly solved by existing approaches.
11.1 Nonphotorealistic Rendering
Not only the production of synthetic plant sketches, but also the entire area of nonphotorealistic rendering will be continuously investigated during the years to come. The subject has been in discussion since the 1990s, and today the second phase in investigating the problems has been reached, with some notable attempts to systemize the area (see [215]) and to classify the related approaches.
Aside from the purely scientific interest, a starting point for the investigation of such representational forms is the realization that many illustrations in books and other traditional print media are not photographs, but rather abstract drawings, sketches, and illustrations [212]. This might be due to technical reasons such as low printing costs. Beyond the cost factor, illustrations seem to offer a better way for expressing the contents of certain kinds of complex pictures. As an example, let us imagine that a medical anatomy atlas consisted only of photos. It would not be very expressive, because photographs can for the most part only vaguely reflect the internal organs of the body and their relationships to each other. Here drawings serve the intent of such a highly specialized thematic much better, since they can represent the important picture content with a few lines. Strothotte et al. emphasized such advantages of illustrations in various articles [194, 213, 214].