We present SurfAirs to enable
on surface and mid-air interaction on vertical displays.
Large vertical displays enable on surface interaction
for precise manipulations,
but also distant interactions for large-scale
manipulations and a wider viewing angle.
A few projects proposed efficient tangible input
to interact with large vertical displays.
They allow precise and comfortable control when on the surface,
but do not enable distant control.
SurfAirs address this issue.
They work both on surface
and in the air.
We created two prototypes: Torch
and Handle.
Torch features a torchlight-like grip.
It can be grabbed in any orientation.
The switch is gear shaped.
Handle features a door handle-like grip.
The switch is a simple button located under the user's thumb.
These tangibles allow on surface interaction for precise manipulation,
and a simple transition from surface to mid-air interaction.
Similarly, users can transition from mid-air to surface interaction.
We conducted two experiments to evaluate SurfAirs.
All input conditions rely on tracking based
on Vicon cameras and infrared markers.
With bare-hand input,
participants used the SideTrigger gesture to click.
For the pointing task, SurfAirs are faster,
less prone to errors and preferred by participants.
The Handle prototype outperforms the Torch prototype.
For docking tasks, SurfAirs are faster than bare-hand input
and are overall preferred.
For the second experiment,
we focus on continuous interaction between on surface and
mid-air interaction.
Participants start the manipulation on surface,
and continue in the air.
We test two techniques for transitioning: Grab and Flick.
With the Grab technique users must press
press the button of the tangible before they leave the surface.
Or when using bare-hand input,
they should perform a SideTrigger gesture
before leaving the surface.
With the Flick transition technique, users must perform a quick surface drag
before leaving the surface either with the tangible,
or with their hand in the bare-hand input condition.
We also test the case where participants start interacting mid-air,
and then continue their manipulation on surface.
To transition from the air to the surface,
participants just come in contact with the wall.
In our experiment, Handle is significantly faster for each task.
It is also participants' preferred technique.