Some areas of applications for synthetic landscaping have already been men­tioned. Particularly in ecology, plant models can also serve as a medium: they transport information about more deeper-lying processes, enabling the viewer to see even invisible things. This way, even the non-expert observer is able to easily gain insight into the underlying mechanisms of the systems. The ef­fect is emphasized if the representation becomes conversant with the types of the argumentation and the environment of the presentation, which is especially possible through abstract renditions.

This transmission of underlying data plays a large role in visualization tech­niques. In biology and botany, visible and especially invisible parameters of ecological systems can be represented using synthetic landscapes. Soil struc­tures, contamination, problem zones and habitats of species as well as sound problems are examples of such parameters, which can be added through spe­cial procedures into synthetic landscapes. Thus, landscape planners, designers and architects will benefit from synthetic plant images, since with a suitable visualization abstract planning results can visualize the desired results, which is especially useful within the framework of competition.

Furthermore, it is possible to represent non-existing plants, such as plants that have become extinct or plants that could still be developed in the future. This might be of great importance to scientists in botany, since genetic changes of economically valuable plants can be visualized before we actually obtain re­sults. This way it could be possible to discuss botanic design parameters di­rectly within the models themselves.

Besides displaying generated virtual landscapes or planning results, the models can be used for visualizing the development of ecosystems over time. So far, the only possibility to visually record such developments have been offered by

interval photography. For long-term processes this is expensive and difficult to do, which is why simulation and visualization of the virtual counterparts can be a good alternative.

Подпись: Section 1.3 APPLICATIONS Another application area for synthetically generated plants is the regulation and measurement of models for the description of physiological procedures in plants, such as the determination of the light interaction and the energy ex­change of the plant with its environment. Here specifically adapted models are imported into appropriate simulators, which compute from these models the values of the thermodynamic parameters.

In yet another application of simulation, realistic plant models are meaningful: driving and flight simulators need vegetation for the spatial orientation of the users. In particular, at ground level the realistic rendering of the vegetation is an essential component in conveying spatial reality.

Currently, the main area of application for synthetic plants is found in filmmak­ing. Virtual plants are used in specially designed external scenes or for special effects involving individual plants. Animation within geographical information systems, the visualization of whole landscapes and the production of interac­tively accessible landscapes for VR systems, and computer games conclude the list of possible application areas for synthetic plant geometry so far.

According to the aspects discussed above, this book consists of four parts. In the first part, which contains the Chaps. 2-6, we address the modeling of in­dividual plants. Based on botanic and mathematical description procedures, Chap. 4 describes the so-called procedural methods for the production of plant geometries, in which the models are synthesized using special algorithms. This is supplemented in Chap. 5 by rule-based modelling. So-called Lindenmayer systems play an important role here.

In Chap. 6, we present rule-based object production, a method that combines rule-based and procedural modeling thereby eliminating a number of problems in the generation of plant geometries. This procedure is discussed with respect to already-existing methods.

The second part of the book is concerned with the modeling of terrain and its plant communities. It covers Chaps. 7-8. Here again, based on the work in botany and geology, a system description is attempted that makes it possible to furnish and handle the required complex data efficiently.

In the third part of the book that is found in Chaps. 9-11, we examine the rendering of synthetic landscapes. Starting with the fundamental algorithms of rendering, different approaches are described for the production of realis­tic looking landscapes. Here in particular the newest, most efficient methods are introduced. Level-of-detail representations play a significant role especially when quick rendering is given priority. Algorithms already make it possible to represent smaller landscapes interactively, and to virtually stroll around in them.

A chapter on nonphotorealistic rendering concludes the third part and briefly addresses the production of further images and their relationship to the arts. This is focussed upon in the last chapter. Here we present the work of several

Chapter 1 artists who motivated us to design interactive modeling programs for plants, Computer-Generated Plants organics, and whole ecosystems. Many of our ideas were developed before by

artists such as William Latham, scientific artists such as Karl Sims or mathe­maticians such as stephen Todd.