This dissertation presents interaction techniques
for 3D modelling of large structures in outdoor augmented reality
environments. Augmented reality is the process of registering projected
computer-generated images over a user's view of the physical world.
With the use of a mobile computer, augmented reality can also be
experienced in an outdoor environment. Working in a mobile outdoor
environment introduces new challenges not previously encountered
indoors, requiring the development of new user interfaces to interact
with the computer. Current AR systems only support limited interactions
and so the complexity of applications that can be developed is also
This dissertation describes a number of novel contributions
that improve the state of the art in augmented reality technology.
Firstly, the augmented reality working planes technique gives the
user the ability to create and edit objects at large distances using
line of sight and projection techniques. This technique overcomes
limitations in a human's ability to perceive depth, and requires
simple input devices that are available on mobile computers. A number
of techniques that leverage AR working planes are developed, collectively
termed construction at a distance: street furniture, bread crumbs,
infinite planes, projection carving, projection colouring, surface
of revolution, and texture map capture. These techniques can be
used to create and capture the geometry of outdoor shapes using
a mobile AR system with real-time verification and iterative refinement.
To provide an interface for these techniques, a novel AR user interface
with cursors and menus was developed. This user interface is based
around a pair of pinch gloves for command input, and the use of
a custom developed vision tracking system for use in a mobile environment.
To develop applications implementing these contributions, a new
software architecture was designed to provide a suitable abstraction
to make development easier. This architecture is based on an object-oriented
data flow approach, uses a special file system notation object repository,
and supports distributed objects. The software requires a platform
to execute on, and so a custom wearable hardware platform was developed.
The hardware is based around a backpack that contains all the equipment
required, and uses a novel flexible design that supports simple
Based on these contributions, a number of modelling
applications were developed to demonstrate the usefulness of these
techniques. These modelling applications allow users to walk around
freely outside, and use proprioception and interactions with the
hands to control the task. Construction at a distance allows the
user to model objects such as buildings, trees, automobiles, and
ground features with minimal effort in real-time, and at any scale
and distance beyond the user's reach. These applications have been
demonstrated in the field to verify that the techniques can perform
as claimed in the dissertation.