[Image 1: Simple landscape plan, showing trees and parking area, from an Apple II+ computer, c. 1980]
[Image 2: 3D model of Kiley's Milller Garden, using 3D software, c. 1998]
Stephen M. Ervin
Assistant Dean for Information Teachnology
Lecturer in Landscape Architecture
Harvard Design School
Abbreviated version of paper presented at the Annual meeting of the American Society of Landscape Architects (ASLA) at St. Louis, Mo, USA Oct 2000
The last twenty years have seen major progress n the development of computer aided design and visualization tools for landscape architects and planners. Image processing techniques are common in professional practice for visualization of alternatives; 2D and 3D CAD software is increasingly useful, with some specialized tools for handling the landscape palette (landform, vegetation, water and atmosphere) ; and GIS capabilities for site analysis and visualization are available on ordinary desktop computers. Nonetheless, there remain many areas for improvement, and numerous research challenges.
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[Image 1: Simple landscape plan, showing trees and parking area, from an Apple II+ computer, c. 1980] |
[Image 2: 3D model of Kiley's Milller Garden, using 3D software, c. 1998]
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The six essential elements that most landscape models require are:
1. Landform; 2. Vegetation 2. Water 3. Structures 4. Animals (including people) 5. Atmosphere
Each of these has it own techniques, and changes, for modeling and visualization.
Landform, usually represented in contours by landscape architects, is more readily represented in computer form as a mathematical surface, from which contours may be generated as needed. These internal surface representations include regular rectangular meshes, (or "fishnet grids"), triangulated irregular networks (or TIN'S), and non-uniform rational b-splines (or NURB surfaces). Specialized software is best for dealing with each of these, but increasingly they are interchangeable formats between programs for modeling and visualization.
[Image 3: NURB surface stones in reproduction of Tanner Fountain]
Vegetation -Ð trees, shrubs, groundcovers Ð present a special challenge to computer models, because they consist of so many separate small pieces (leaves, branches, twig, bark) and require upwards of millions of polygons to represent as full 3D models. The simplest and most common approach to representing vegetation is to use photographic textures, which work for simple visualizations, but havenÕt the detail to use for foreground elements. Algorithmically generated 3D models of trees can be produced by some software, and this provides the added benefit of being able to model growth over time, as well potentially interaction with natural systems such as sunlight, crowding, soil conditions, and etc. These kinds of ecological rules can be used to model various plant communities such as fields and forests, in some software.
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| [Image 4: TreePro generated 3D tree; used by permission] |
[Image 5: Birch Forest by Blueberry3D; used by permission] |
Water is an essential element in many landscapes, even when not visible. In its visible forms, whether natural or built, water has special characteristics that require advanced rendering techniques to capture its essential reflectivity, transparency and refractivity. Simple flat blue planes suffice for ordinary renderings, but to represent ripples, sparkles, waves and even sounds, animation and multimedia techniques are really required.
[Image 6: Water spout in a pool, showing ripples and reflectivity of liquid surface]
Structures in the landscape are readily modeled in common CAD software, and increasingly landscape architects work in collaboration with other professionals such as building architects and engineers to create integrated models. Animals, including people, are harder to model, but are essential elements and should not be omitted from landscape models and visualizations.
Atmosphere includes light in the environment, both natural and artificial, as well as other influences, such as water, wind, and dust which affect strongly how we perceive the landscape. The difference between long morning shadows on a cloudless day, deep fog with only dim ambient lighting, and a full moon overhead can have a profound impact upon the appearance of any landscape, garden or forest. Modern rendering software provides considerable control over lighting source and parameters, which should be exercised when creating landscape visualizations.
[Image 7: Rendering of Atmospheric conditions]
Although many advances have been made in being able to model landscapes and landscape elements, challenges still remain. The landscape will always be bigger, more complex, more encompassing, than any computer representation. And so techniques of abstraction, simplification and representation will always be essential. The goal for most landscape modelers is not 'photo-realistic' or even 'bio-realistic' representations, but effective ones that tell the story required for somunication with clients, collaborators, or even with oneself in the process of landscape planning ande design.
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For a more in depth treatment of this topic, see http://www.gsd.harvard.edu/~servin/ascona