Web3D RoundUp: Looking Backwards and Forwards

Vol.34 No.2 May 2000

Alice: Model, Paint & Animate - Easy-to-Use Interactive Graphics for the Web

Randy Pausch and Clifton Forlines
Carnegie Mellon University

Figure 1: The newest version of Alice incorporates a no-typing, drag-and-drop interface for building animations and interactions. Alice’s many commands are easily accessible and common syntax errors have been virtually eliminated.

Figure 2: Students in Carnegie Mellon’s Building Virtual Worlds course use Alice to create worlds like this in teams of four in under two weeks. Guests are encouraged to lead this class of animals in a virtual workout.

Alice ( is an interactive 3D graphics programming environment for Windows 95/98/NT/2000 built by the Stage 3 Research Group at Carnegie Mellon University. The Alice project was designed as a public service to the wider computing and artistic communities. Our hope is to make it easy for novices to develop 3D environments, explore the new medium of interactive 3D graphics and share their creations on the web. We believe that computer programming in and of itself is not inherently difficult; it is the tools that are used to program that people may find hard to use. By discovering an easier and more natural method of presentation and implementation of 3D graphics, we hope to make graphics programming accessible to a wider audience.

The current version of the Alice authoring tool is free to everyone and can run on computers that are commonly available for reasonable prices. To date we have had over 80,000 copies of Alice downloaded via the web. Worlds created in Alice can be viewed and manipulated inside of a standard web browser once the Alice plug-in has been installed (a 750KB download). Users who do not have their own website can choose to "Send their World to a Friend" - we host their world on our server and their friend receives email telling them to visit a specific URL. The average size of such a world is under 65KB.

The newest version of Alice, known as Alice99, incorporates a no-typing, drag-and-drop interface for building and interacting animations. Alice99 ships with an interactive on-line tutorial that guides novice users through the steps of building their first few worlds. Alice’s many commands are easily accessible and common syntax errors have been virtually eliminated. These features allow the user to create 3D content, complete with original models and painting, without ever touching the keyboard, let alone typing a line of code (see Figure 1). Consequently, novices and experts alike are free to focus more on the content of their worlds and less on learning the tool. We have observed children as young as eight producing and sharing interactive 3D environments with their friends on the Internet in a little more than an hour. However, Alice does run on top of C++ and Python (a free and "Turing Equivalent" programming language), so expert users are not limited to Alice’s built-in commands.

Alice also includes the Teddy modeler, developed by Takeo Igarashi of the University of Tokyo. Teddy allows the creation of 3D hierarchical models using simple 2D mouse strokes. Coupled with AlicePaint, even novice users can quickly make and paint their own objects in their creation of 3D worlds. In addition to creating original models, users can import .3DS, .OBJ and .DXF files - all of which are available in abundance on the World Wide Web.

Alice is currently being used in a variety of classrooms, ranging from high school to college level. Users include Carnegie Mellon University’s Building Virtual Worlds class, in which technical and non-technical undergraduate students work in teams building virtual environments (see Figure 2). Alice is also used as a rapid prototyping environment for conducting virtual reality research.

Carnegie Mellon University provides the authoring tool, plug-in and hosting service free of charge. Interested parties should visit to download both the authoring tool and plug-in and to view some on-line demos. Work from the Building Virtual Worlds class can be viewed at

Randy’s reaction after last SIGGRAPH: "As always, talking to the Web3D RoundUP makes one feel like China in a Bullshop. Through careful practice, Takeo Igarashi and I were able to show off both the Alice 3D system and his brilliant Teddy modeler to the delight of a large number of 3D enthusiasts. There’s nothing like an audience armed with nerf weapons to bring the best out in speakers!"

Randy Pausch and Clifton Forlines
Carnegie Mellon University

The copyright of articles and images printed remains with the author unless otherwise indicated.