dan's face  
Daniel C. Robbins

Navigation


Related Pages:

Users (especially non-gamers) tend to get lost in many 3D systems that require them to navigate. We avoid this problem by keeping the space simple (a linear hallway), by choosing a metaphor appropriate for the context (viewing art in a gallery), and by constraining the navigation. 
The structure of our TaskGallery environment is optimized to let users easily shift focus and context. Navigation is as simple as moving forward or backward in a linear hallway

First person games typically allow users to move in a freeform fashion (within the constraints of the architecture). For novice users and for those users who do not have well-developed navigation skills this can be untenable. In our design, we instead provide higher-level controls. For example, a user may be thinking she wants to "go to the next room." If this user had to rely on game-style free-form navigation controls, she might easily get lost, or, at best, have to wander around to find a particular room. What we do to fix this, is provide an on-screen control called Next Room. Clicking on this control causes the user's viewpoint to automatically be brought forward to the next room -- as if a virtual tour guide took the user's hand and led them down the hall. The Next Room control sits within an arrangement of on-screen controls in the lower left-hand corner of the screen. 

Thus, we provide a few simple controls rather than a general egocentric navigation mechanism. 

Normally only the person icon is displayed. When the user moves the cursor near the person icon, the navigation controls appear.

These on-screen controls allow the user to “jump” backward, forward, home (primary view), and to a bird's eye view showing all the tasks in the TaskGallery. Each jump control starts a one-second camera animation from the current position to the desired target. Our user studies showed that users did not become disoriented in the 3D space when using these controls, and that they could easily find their desired tasks.

Looking left causes the user to glance at their virtual left-hand, in which is a palette for choosing application and creating new tasks. Looking right brings into view the user's virtual right hand, within which we show a standard file-browser (Windows Explorer).

The standard file-browser could easily be replaced with any number of visualizations, better suited to browsing large amounts of data.

Navigation functionality provided by the on-screen controls is also duplicated via the keyboard. The default mapping is as follows:

As new input devices become available, we will take advantage of these to provide even easier navigation. Currently there is also a trend to add special purpose keys and controls to keyboards. One can easily imagine several controls, optimized for TaskGallery navigation, that could appear on a common keyboard.