Artikelbeschreibung:
Project Looking Glass (LG3D) is an open source project to explore a much richer desktop user experience to the desktop and to applications, through 3D windowing and visualization capabilities. It exploits significantly improved 3D graphics rendering capability of today's PCs, which was not available when many of the foundations of today's desktop system were designed.
Project Looking Glass is based on SLAX with Java technology. Project Looking Glass is an open source development project evolved from Sun Microsystems' Advanced Development division. It supports running unmodified existing applications in a 3D space, as well as APIs for 3D window manager and application development.
In the prototype, windows displaying applications are no longer stacked upon each other with flat icons and buttons to represent them; they are viewed in a 3D environment and manipulated as 3D objects.Project Looking Glass will allow users to switch virtual desktops by panning - by clicking around the right edge of the screen. Users can interact with their existing 2D applications and will be introduced to new 3D applications.
Project Looking Glass is moving beyond the boundaries of old environments to revolutionize the use of the desktop. When completed, it will work alongside applications designed for a 2D window system, without application modifications.
In order to achieve the design goals described, the following features have been, or need to be, supported:
- Java Technology-based APIs and Implementation
Java technology is the primary development language because of the productivity gains it brings, its language safety features, and the rich set of supporting APIs it provides.
- Built on Top of Java 3D Technology
The LG3D API and implementation leverage the Java 3D technology. In addition, LG3D provides additional features including a component architecture and an animation system in order to simplify writing rich user experience applications.
- Model Loader Integration
Support for model loaders is considered a key feature of LG3D technology, as it brings visual designers into the development loop. A special LG3D component named ModelLoader has been introduced for that purpose. It provides a simple yet powerful mechanism to load a 3D model from a file and bring it into the LG3D environment.
- Client-server Scene Graph
The client-server scene graph allows multiple processes to share the same virtual 3D universe. This technology also allows the platform to execute an LG3D-aware 3D application in a separate process (even on a remote machine), while it displays a 3D user interface integrated within the single virtual universe with which the user interacts. Like the X client-server model, this enables clean isolation among applications and the platform.
- Server-side Behavior Execution
Animation typically operates on a scene graph per frame. A mechanism to execute animation on the server side is provided, so that client and server do not need to communicate per frame. The client specifies types of animation with parameters, such as duration.
- Generic Event System
Rich user feedback and componentization of the library were two key requirements for the platform. In order to implement rich user feedback, a significant amount of state and event information need to be passed across the system. This can result in the platform components getting too tightly coupled if we solely rely on method invocation. An asynchronous generic event system is supported at the platform level in order to decompose library features into smaller pieces that interact with each other in a loosely coupled fashion.
- Event Adapter and Animation Components
The platform introduces abstraction interfaces called 'EventAdapter' and 'Action' that disengage the event receiver code and the animation implementation. This enables a rich set of components to be hook up together to achieve a customized feedback with little effort. In future, an event driven animation system with simple behavior composition will be introduced. It will allow developers to hook up the components without coding.
- Component Scene Manager
The Scene Manager takes over the role of window manager for a 3D scene, since typical LG3D-aware 3D application user interfaces have unique shapes not limited to a window shape. The Scene Manager interacts with the user and applications. It implements a customizable management policy for applications running in the environment and is responsible for arranging those in the 3D space.
- Abstraction Layer for Existing Application Integration
The abstraction layer can be roughly divided into two major areas: the Foundation Window System (FWS) module, and the Native Window representation module. The FWS module provides the integration with the underlying window system, including application visual capture and event delivery integration. This module includes a set of interfaces for implemention plugins for various native window systems. The Native Window representation module sits on top of the FWS, and provides abstracted representation of the native window application's visual aspects in the 3D space.
- Swing Integration for 2D Widget Set Support
While developing a 3D application, sometimes 2D user interface components makes sense. Examples include a file dialog window and text input-output fields. Instead of introducing a whole new set of APIs, LG3D provides a mechanism to incorporate Java's Swing widget into its 3D environment.
