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Given by Paul Coddington, Alvin Leung, Krysztof Walczak, Byeongsoeb Ki at Rome Lab Quarterly Review for CIV on June 28 96. Foils prepared 23 February 97
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Summary of Material
| Goal is to provide interactive 2D and 3D viewing of terrain via the Web, with GIS functionality for accessing and overlaying spatially referenced data |
| Terrain data is currently elevation plus satellite images; GIS information is place names, census data, images, Web pages, simulation results |
| Java (for 2D) and VRML (for 3D) are used to display information and images using the Web |
| Need to minimize data transfer from the server in order to obtain real-time performance |
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Terrain Rendering and GIS using Java and VRML Paul Coddington, Alvin Leung, Krysztof Walczak, Byeongsoeb Ki
Summary
2D Terrain Viewer Java Applet
Functionality of the 2D Viewer
Search Capability
Current Status of 2D Java Viewer
3D Terrain Viewer Using VRML
Describing Terrain in VRML
Current Status of VRMLViewer
Future Work
Outside Index
Summary of Material
HTML version of Basic Foils prepared 23 February 97 
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HTML version of Basic Foils prepared 23 February 97
Full HTML Index
| Goal is to provide interactive 2D and 3D viewing of terrain via the Web, with GIS functionality for accessing and overlaying spatially referenced data |
| Terrain data is currently elevation plus satellite images; GIS information is place names, census data, images, Web pages, simulation results |
| Java (for 2D) and VRML (for 3D) are used to display information and images using the Web |
| Need to minimize data transfer from the server in order to obtain real-time performance |
HTML version of Basic Foils prepared 23 February 97
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| Written in Java, so can be run from within a Web page on any client computer |
| Images and data are provided by the Web server, but user interface and graphical display is done on the client for faster response and ease of use |
| Terrain images are stored in JPEG compressed segments which are fetched when needed, or prefetched where possible |
| GIS data is accessed from various databases |
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| Starts with satellite image of a region; user can click on area of interest, search for a place by name, or overlay data |
| Provides panning and zooming, and jumping to an area by mouse click or name search |
| Hyperlinked place names, data, images, etc can be overlaid onto the terrain image |
| Clicking on hyperlinked overlays displays information in separate popup or browser window |
HTML version of Basic Foils prepared 23 February 97
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| A database search capability is provided to find a place and to find information about that place |
| Currently this can search various databases of place names, census data, photographs, and Web pages containing information about a town or place, which could include weather forecasts, street maps, local services, phone book, etc. |
| Searching of other GIS databases can be added |
| Different types of databases can be accessed using CGI programs or JDBC to make SQL requests |
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| Prototype is operational with some simple terrain and GIS data - can be customized to a particular Command and Control scenario by adding extra data types and functionality |
| The performance is a bit slow, especially for zooming and panning - will improve with further program optimizations and better Java interpreters |
| Needs to be integrated with 3D VRML version, which will probably require Java3D API |
| URL for demonstration is http://www.npac.syr.edu/projects/terrain/NYS/ |
HTML version of Basic Foils prepared 23 February 97
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| Virtual Reality Modeling Language (VRML) is the standard method used for describing and displaying 3D worlds on the Web |
| VRML browser provides 3D rendering and ìflight simulatorî user interface, which allows real-time interactive flyover of a 3D terrain model, with overlays of GIS data |
| VRML data for terrain is very large - main problem is to minimize amount of data to be downloaded and complexity of scene to be rendered, in order to obtain real-time display |
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| Terrain is represented in VRML as polygons (constructed using digital elevation data) with vertex coloring or a texture map for displaying terrain features (obtained from satellite images, maps, or simulation results) |
To obtain real-time animation, have reduced the number of polygons to be rendered by using
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HTML version of Basic Foils prepared 23 February 97
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| Prototype is operational with some simple terrain and GIS data; overlays can be added, such as clouds, snow, buildings, hyperlinked objects |
| More tuning can be done, but the current performance is good for VMRL data accessed locally from disk, but too slow over a network (data format is uncompressed ASCII) |
| VRML is not flexible enough to add extra capabilities - it is not a programming language |
HTML version of Basic Foils prepared 23 February 97
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| VRML is too limited for this application |
| Sun and SGI are developing Java3D, a set of libraries and APIs which will merge and extend Java and VRML for 3D rendering applications |
| Java3D will allow programming of additional capabilities, and downloading of compressed binary data which can be converted to VRML format on the client side |
| Java3D is based on Inventor, but wonít be available until end of 1996 - in the meantime, we can develop new capabilities using our Web Inventor browser |