Natural Navigation and Information Seeking
With traditional GIS, a user analyzing data generally begins with a purpose, an idea of which data layers to analyze, and some specific questions he needs to ask in order to reach his goal. The aforementioned user may now open GIS layers which reflect the income distribution, infrastructure and land development restrictions in order to pinpoint areas of interest. This step can be performed with virtually identical results in 2-D or 3-D GIS. But upon completing the analysis with 3-D GIS, the user may choose to immerse himself in the selected region and freely navigate the area.

Figure 1. Virtual environment

Within our theoretical scenario the user that starts a virtual walk in the promising area will be given visual data of layers that he had not considered or perhaps did not even know existed in the database. For example, the user will find himself inside the virtual environment shown in Figure 1.

Information contained in this visual environment includes the trees and the true visuals of the houses on the ground. What kind of trees are these? A simple query will give the answer. Is this an indication of the type of soil in this area? Is the soil suitable for a structure such as a mall? The houses look quite expensive; are these influential people who may make it difficult to open a mall so close to their property? These are additional layers of data that need consideration and present themselves very naturally to a user navigating through this region.

This highly visual navigation will provide the user a very natural way of gathering data, simply by being inside a realistic replica of the area of interest and looking around. Such data gathering may not necessarily start with a specific goal or an idea of what to look for; such criteria may develop as the user studies his environment as was indicated in the previous example.

Architectural Models Integrated into the 3-D GIS Environment
Traditionally during the design phase, structures are rendered with software such as 3D Max, Maya and so forth, which place these structures in beautiful settings with happy people walking about and with sunshine that is almost heavenly. Designing a structure on a computer and rendering it from a variety of angles is a useful process, but with the establishment of 3-D GIS it will take on a completely new dimension. Let us say the user has selected several possible locations for the mall and wishes to visualize how the proposed mall design will look in each of these locations. The process of taking the structure design and placing it inside the 3-D GIS environment should be as simple as moving a window on the desktop. GeoTech’s 3-D GIS Environment makes it just that simple. Without the need for conversion, a user may take structures modeled in a variety of popular design software, such as 3D Max, Lightwave, etc., and simply place them in the GIS environment. Now the user is able to see how the structure blends with the environment, and even walk within the structure, looking out into the realistically rendered environment (Figure 2), complete with trees, buildings and even 3-D terrain textured with high resolution satellite photos. Determination of design alterations, further GIS analysis, and preparation of promotional material can all be conducted from within a single environment.

Figure 2. The structure blends with the virtual environment

Analysis for Three Dimensional Structures
Creating three dimensional structures gives the user more than the capacity to visualize an area realistically without having to travel there in person; it gives the user additional options for analysis. For example, the mall in question may have been designed to withstand an earthquake measuring 7 on the Richter scale. But this design advantage will lose its relevance if a nearby multi-story structure cannot withstand this quake. That tall building could collapse right on top of the quake-proof mall. With 3-D GIS the building definitions can be altered in the software to simulate an earthquake complete with an estimate of the debris distribution. In fact, GeoTech has conducted work in this area in which more than 15,000 buildings were modeled automatically and thousands of these structures were virtually destroyed in real-time (Figure 3).

Figure 3. More than 15,000 buildings were modeled automatically and
thousands of these structures were virtually destroyed in real-time.