Interactive Geospatial Visualizations

Abstract

Geographic Information Systems are becoming increasingly ubiquitous in the analysis of large geospatial data sets. In order to present this data visually in an interactive fashion, Unity, an integrated development engine used to create video games, has been utilized to fabricate fully-explorable, three-dimensional game levels using real-world geographic data and high-resolution orthographic photography. Unity is freely available for web deployment, which has contributed to its rapid adoption by colleges and universities. In addition to modeling the photorealistic terrain, the Unity game engine can be used to visualize any type of data. These visualizations may be enhanced with the addition of three-dimensional models created in Google SketchUp. This free modeling software allows for easy creation and texture-mapping of buildings and other landmarks. Models produced in SketchUp can be imported into the Unity environment, bringing a notion of user familiarity to the regions being modeled. This research project focuses on flood modeling for areas of the French Broad River and Swannanoa River districts in Asheville, NC. Several river levels are created to represent different flood stages, and they can be interactively manipulated. The rivers' levels are modeled as polygonal meshes (a collection of lines, vertices, and faces) based on shapefile image inputs, and displayed using an animated water shader. A shapefile is a widely adopted geospatial vector format that is computationally easier to process than a topological format. This project helps bring environmental computer modeling to wider audience, thus allowing for detailed, interactive visuals to be used for decision makers. Utilizing a real-time game engine allows model interactivity in almost real time, which previously was so computationally expensive that it precluded display and manipulation on consumer grade workstations.