An example of a large high-resolution display is one with dimensions 18ft x 6ft, and resolution 16000 x 6000. To be able to see the entire display a user needs to be at a distance. For this scenario, pointing is a simple and intuitive way to interact with the display. An example of a large high-resolution display is shown in Figure 1.
One of the most common type of pointing techniques is ray-casting, in which the cursor is positioned at the intersection of an imaginary ray from the user hand and the display. On large high-resolution display ray-casting has some issues.
In this work we present two new ray-casting based interaction techniques that address those issues:
This work was developed at Virginia Tech in collaboration with Dr. Regis Kopper, Dr. Ryan McMahan. We all equaly contribute with ideas, implementation of techniques, design and running of the user study, analyzing results, and writing a paper.
We worked under the guidance and supervision of Dr. Doug Bowman.
When pointing from a distance any small hand movement is amplified when the ray intersects with the display. This lack of precision makes impractical the use of simple ray-casting techniques when interacting with a small target from a distance on a large high-resolution display.
Some of the issues are:
ARM Ray-Casting makes easy to switch between:
It is a bimanual interaction technique. With a device on the dominant hand the user points to the area of interest on the screen (absolute mapping). Then the user clicks and hold a button on another device on the non-dominant hand to make the cursor move slower (relative mapping), making it easier for the user to precisely place the cursor on the desired target at the screen.
The idea behind ZELDA is to provide users with a magnifying glass (a zoom window) for more precise interaction when near the desired target.
ZELDA is also a bimanual interaction technique. The dominant hand is used for pointing and clicking, the non-dominant hand controls the placement of the zoom window, its size, and magnifying factor. The user can freeze the zoom window position on the screen when desired.
Figure 2 shows a user pointing to the display and placing the zoom window over small icons.
We ran a user study composed of atomic (one-step) and complex (multi-step) tasks.
We observe a variety of user strategies when completing complex tasks. The strategy is a set of decisions made by the user on how to complete the task. Some examples of strategies are:
We observe that ARM Ray-casting and ZELDA improve the selection and manipulation of objects compared with basic ray-casting, but the user performance is highly dependent on user strategy.