In regional planning, visualization of landscape by computer graphics is important for estimating the impact of the plan on environment. In this study, several methods for landscape visualization such as utilization of plant modeling, development of algorithm and software for terrain visualization and applications on World Wide Web are described. These methods are powerful tools for presentation and they can also be used for analysis of environment.

In landscape simulation, one of the technical difficulty was the modeling of plant shape. Visually realistic model of plants is necessary for the simulation but it has been difficult before recent progress of plant modeling technique enabled the realistic modeling of plant shape.

Here, the method of simulating very realistic landscape was developed by using plant modeling technique and practical applicability and performance were tested by making the landscape images. 3-D shape data of the trees were modeled and realistic images were rendered by landscape simulating system with plant modeling. In the case studies, landscape of a university campus (Numazu Campus, Tokai University) was simulated (Honjo, T. and Takeuchi, 1995).

As a landscape simulating system, AMAP (Atelier de Modelisation pour l'Architecture des Plants) was used for the visualization. AMAP is a CAD system for landscape design with high-precision plant modeling technique. It generates a three dimensional (3-D) plant shape of some hundred species and also simulates the plant growth base on the botanical knowledge. Examples of plant shape generated by AMAP are shown in Fig. 1. By using AMAP, it is possible to simulate scenery change caused by the plant growth or effect of changing plant species.

Fig. 2 Process of Landscape Simulation Using Plant Modeling

Example of the landscape simulation of university campus is shown in Fig. 3. The result shows that photo-realistic simulation of the landscape was possible by this method.

In the planning, simulation of the landscape by using plant modeling also contributes testing the accuracy of the DEM data or the plant data and helps to realize the multiple information instantly. In the estimation and prediction of environment, realistic images are good material for public discussion and are powerful tool for environmental assessment.

By mapping a surface texture data such as Landsat data or aerial photo on DEM, it is possible to make a realistic terrain images. We developed two software for texture mapping.

Fast rendering algorithm (Honjo, T. and Saito, 1993) for texture mapping is described in Fig. 4. The software using this algorithm was called T-Maker and was developed on Unix system by using ANSI C language. The algorithm of T-Maker was also used on WWW system.

Fig. 5 shows another software for visualization of terrain, named LAND3D. The algorithm used for LAND3D was ordinary 3-D to 2-D projection. LAND3D was written by Visual C/C++ and run on MS-Windows 95. (LAND3D is a freeware and is distributed on Nifty Serve, forum "fyamap".)

To make a realistic scenery by CG, the effect of haze and fog sometimes plays a significant role. LAND3D can simulate an effect of haze and fog. Example images are shown in Fig. 5.

The effect of cloud is also important. By adding the effect of cloud and changing its shape and thickness, the realistic expression was possible as shown in Fig. 6. Images of Fig. 6 were made by using KPT Bryce (MetaTool) as a rendering software.

VRML (Virtual Reality Modeling Language) is a language for 3-D modeling and visualization on Internet and is also a good software for terrain visualization. In Fig. 7, VRML was used for the terrain visualization. Example of the program and images are shown. GL-View was used as a browser.

WWW is a powerful tool for distributing information. The development of visualization software on WWW enables easy public access to the environmental data and gives material for discussion for environmental assessment.

3D images of terrain was visualized by overlaying texture data on DEM. CGI (Common Gateway Interface) was used to interfacing between software for making 3D terrain images and WWW pages. A part of T-maker is used for the terrain visualization in this system. User can set many parameters such as view point position and viewed area on the WWW page in Fig. 8. In the example of Fig. 8, scenery of Kanto district in Japan can be seen from any direction.

Local meteorological acquisition systems have been constructed in many areas. The distribution of the data using protocols or software of Internet is preferable instead of conventional communication software or fax considering the widespread availability of Internet. Prototype of meteorological information system using Internet or Internet protocol was developed (Honjo, T. et al., 1997). The diagram of the system is shown in the following Fig. 9.

Fig. 9 Diagram of Meteorological Information System

In the system, software for data transfer from local station to WWW system by E-mail was developed using PPP and SMTP to enable data acquisition in the area without LAN . 3D maps of meteorological data like temperature, relative humidity were shown on the homepages in Fig. 10.

These methods are powerful tools for providing the information to public and will be used for the interdisciplinary discussion about the environmental planning.