CHI 2000 • 1-6 APRIL 2000
Short Talks
Menus Beyond the Desktop Metaphor
Fred A. Voorhorst, Helmut Krueger
IHA-Ergonomie, ETH Ziirich
Clausiusstrasse 25
8092 Ztirich, Switzerland
+41 1 6325530
<surname>@iha.bepr.ethz.ch
ABSTRACT
Augmented Reality systems integrate real and virtual
objects, allowing for a new view on the implementation of
menus. This paper describes experimental research in
support of making menus grasp-able, i.e. easily accessible.
KEYWORDS
Graspable user interfaces, usability, AR, use of menus.
INTRODUCTION
A menu can be any type of representation f an organization
of tools or functions, such as pull-down menus, pop-up
menus, tool pallets, and so on. The main objective of
using menus is to give a structured overview of the tools
and functionality at hand. Menus should, on the one hand
be easily accessible, and on the other hand not crowd the
workspace. Optimization of menus may improve the
usability of the interface.
Augmented reality systems (AR) provide the possibility to
explore the use of menus in an unconstraint way. AR is a
new type of VR systems emerging on the reality-virtuality
continuum [4]. VR and AR open new possibilities for
interface design such as e.g. gesture based HCI [3, 5]. AR
ahs the additional advantage of supporting the combination
of physical objects and computer generated objects. For
example, aphysical room can be augmented with computer
images of newly designed furniture with the purpose of
evaluation before the actual purchase.
THE AUGMENTED REALITY SYSTEM BUILD-IT
Build-It [2, 5] is an AR based planning tool based on
intuitive manipulation for the support of planning and
configuration tasks. Build-It presents the user with two
views: a table view showing the virtual environment in
plan, and a wall projection, showing the virtual
environment in perspective. The plan view contains a
(virtual) camera that determines the image presented on the
wall view. Build-it has a so-called graspable user interface.
An interface is called graspable when each function of the
interface is operated by means of a dedicated physical
device. The device a function is operated with serves as a
graspable function [ 1 ].
© Copyright on this material is held by
the author(s).
Martin Biehsel
IKB, ETH ZiJrich
Tannerstrasse 3
8092 Ztifich, Switzerland
+41 1 6322429
mbichsel@ikb.mavt.ethz.ch
Two reasons suggest he advantage of a graspable user-
interface for the development ofuser-ffriendly HCI compared
to a normal graphical user-interface approach [6]. First, a
physical object naturally invites users to act. For example,
a small ball invites to be squeezed while a large ball invites
to be kicked. Second, the use of physical objects make it
possible explicitly distinguish between functions by
linking them to different actions or objects. With build-it,
the interaction proceeds by means of rectangular bricks that
are tracked using an infra red detection system. An object is
selected by simply placing a brick on top of it. The object,
when selected, can be freely moved around. The object
becomes deselected when the brick is covered.
IMPLEMENTING MENUS FOR BUILD-IT
The technical implementation of Build-it (two projectors
and an infrared tracking system) can be used to the
advantage of the implementation of menus. Both the
tracking of the bricks and the projecting of the computer
image is done from above the table surface.
Figure h A possible implementation f r an AR system would be
selection directly from a catalog and dragging it on the desktop.
One of the potentials of this technical set-up is the
possibility to combine various information carriers uch as,
e.g. by combining computer images with hand drawings.
Build-It gives the possibility o take the menus beyond the
desktop metaphor, as allows for looking at hardware
solutions such as a real catalogue, from which objects can
be selected irectly (see Figure I). Implementation only
requires a unique code on the page of the catalogue, that can
be picked-up by the system's infra red device. Potentially,
the page layout itself can serve as coding.
EXPERIMENT: MAKING MENUS GRASPABLE
In a small experiment wo principles of implementing
menus were tested. First, with respect o selection: a menu
can be accessed either direct or through a handler. Second,
with respect o interaction: the menu or handler either is
virtual or real.
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