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3D Land Navigator

1. 3D Land Navigator

Based on our WorldShow3D browser and its application APIs, we have developed a land navigator software to display land surfaces in computer 3D graphics and to let the viewer freely cruise in the sky. The basic idea is like this: first take the aerial images of the land surface and divide them into pieces of the same size. Each piece of the image is called a map cell, and its 3D geometries can be constructed according to the actual physic dimensions and the interested objects. From the viewer's position, the navigator software will load the nearby map cells and create 3D texture mappings from their geometry data. So the viewer will see a 3D geographic scene on the computer.

Some key features of this application are listed below:

  1. Region: The geographic surface of the earth can be divided into many regions. A region can be a state, a province, a district, a city, or even a village, and it can be distributed and stored in its own web server. When the viewer moves beyond a region's boundary, a new linked region can be loaded into the navigation software and the viewer then starts a new journey in the new region.  With this approach, it is not necessary to use the high-resolution coordinates to describe the world objects in a large dimension environment. mapcell.jpg (15177 bytes)

  2. Map Cell: A map cell represents a single aerial image of a part of the earth surface. A region consists of numerous map cells which seamlessly cover all the geographic area. Each map cell can have a data file which is used to define the  geometries, texture mapping, user interactions, and extra objects. The navigation software always loads and displays the map cells that are near the viewer's position. For those out-of-sight map cells, their texture and geometry resources are released for recycles.

  3. 3D Terrain Capable: Each map cell can have any number of mesh points, which are configurable and can irregularly distribute on the surface. These mesh points provide a flexible way to construct 3D terrain for the map cell. All the mesh points are defined in the data file of the map cell.

  4. Dynamic: Any world object of Object3D can be attached to a map cell, and it will be loaded only when the map cell becomes visible. The inherited dynamic function from Object3D provides a standard interface to simulate a verity of dynamic behaviors.

  5. User Interaction: The software provides two approaches to intercept user's mouse input for each map cell. The first one, CellAction, is defined by an image region on the map cell. When the mouse touches this region, it can activate a background sound and other world objects. Another one, ActionHandle, is a plane handle attached to the map cell and it's defined in the cell data file.

  6. Easy to Build: With a little training, a person without previous programming experience can easily build a 3D city of his/her own.

2. Download Free Demo: Navigating Detroit's Downtown

  • You need Java 2 version 1.4.0 or later to run this application. In addition, you need to install Java 3D version 1.3.1 or later on your machine. detroit.jpg (9377 bytes)
  • Your graphics card should support 3D acceleration and have at least 16MB memory. This application is disk reading intensive, and we suggest your computer have a fast CPU in order to get the best performance.
  • Download the following package to navigate Detroit's downtown:

detroit.jar (about 9MB) 

  • Start the application:

java -Xmx128M -Xms128M -jar detroit.jar

  • Wait 15 seconds to let the application fully loaded. Then point your mouse on the main window. Pressing the mouse's left button and moving around, you will be moving around above Detroit's downtown. Pressing the mouse's right button and moving back-forth, you can descend or rise in a certain range.

3. Future Development

  • We're currently improving this software to make it more efficient, more robust, and more general.
  • We're developing a texture mapping tool that will make the construction 3D geometries on map images more easy and accurate.