|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:
- 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.
- 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.
- 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.
- 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
- 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.
- 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
- 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.
- 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
- Download the following package to navigate Detroit's downtown:
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.