“The most overlooked advantage of owning a computer is that if they foul up there’s no law against whacking them around a bit” – Eric Porterfield


Computers have no emotional feelings, and even if they did they would hardly have any idea what we were doing to them anyway.


Making a Sensible Computer


Head Tracking

Not only does head tracking allow the computer to draw the world, it also tells the computer where we are and what we are looking at.

Gaze-based selection involves using the direction the head is pointing to select objects.
Gaze-based navigation involves using the direction the head is pointing to determine where to go next.

Where are we?

An augmented reality system uses the physical world as its environment, but a virtual world will most likely be different from the virtual world.
Current head tracking systems have limitations to their range.
Even if they had no range, projection display systems and wireless communications limit the range within which we can deliver visual input.
However, even with unlimited range, it is not practical to allocate as much space in the real world for freely moving in the virtual world.

This poses a problem for navigating to other locations within the virtual world.

Haptic Navigation Techniques

Realizing the goal of accurately reproducing the sensation of moving within an environment is a difficult goal.
While the reproduction of 3D visuals based on head motion is relatively straight forward, reproducing very complex motion of walking is much more difficult.
The very physical nature of the activity means that the device must be a mechanical device and includes all of the typical problems associated with haptic devices:

Examples include:

Software Navigation Techniques

The practicalities of haptic systems force us to consider less intuitive navigation methods.
These methods are very practical and useful for navigation, but they disrupt attempts to make the interface invisible.

Can you see me?

Walking simulation systems and/or gesture based systems require tracking parts of the body that may prove awkward for traditional tracking setups such as magnetic systems.

Can use computer vision techniques to estimate the motion of the legs or to follow simple gestures.

Some simple techniques can give a rough estimate of the location of the user and their limbs:

Can you feel me?

Although truly flexible haptic systems are many years off, physical props can replace them in specific situations.