%Twenty years after Sutherland's work \cite{sutherland65}, the Neuromancer describes the \defword{cyberspace} as an alternate reality out of the physical world, created with machines \cite{gibson84}.
Decades after Sutherland's work \cite{sutherland65}, novels like Neuromancer \cite{gibson84}, Snow Crash \cite{stephenson92}, and more recently Ready Player One \cite{cline11} describe immersive virtual worlds as alternate realities in which people can socialize, play, or even work.
The new brand of Facebook, Meta, is a reference to Snow Crash's \defword{metaverse} and shows the new focus of the company on immersive social network, with Spaces then Horizon\footnote{\href{https://web.archive.org/web/20191005002238/https://www.facebook.com/spaces}{https://www.facebook.com/spaces}, \href{https://www.oculus.com/facebookhorizon/}{https://www.oculus.com/facebookhorizon/}}.
-Similarly to other immersive social network like Mozilla Hubs\footnote{\href{https://hubs.mozilla.com/}{https://hubs.mozilla.com/}}, VRChat\footnote{\href{https://hello.vrchat.com/}{https://hello.vrchat.com/}}, and RecRoom\footnote{\href{https://recroom.com/}{https://recroom.com/}}, the objective is to enable people to get together in a virtual environment, and interact with each other as if they were in the same room.
+Similarly to other immersive social network like Mozilla Hubs\footnote{\href{https://hubs.mozilla.com/}{https://hubs.mozilla.com/}}, VRChat\footnote{\href{https://hello.vrchat.com/}{https://hello.vrchat.com/}}, and RecRoom\footnote{\href{https://recroom.com/}{https://recroom.com/}}, the objective is to enable people to get together in a virtual environment and interact with each other as if they were in the same room.
Such immersive virtual environments require easy and usable ways to perform atomic actions such as the study presented in the previous section.
%selecting and manipulating objects, or navigating the environment.
%Many of them represent emotions, therefore we leverage this information for the design of the selection techniques.
\begin{figure}[htb]
- \def\fh{3.7cm}
+ \def\fh{3.2cm}
+ \includegraphics[height=\fh]{emoraye_touchpad-menu}
+ \hfill
%a)
\includegraphics[height=\fh]{emoraye_2d-menu}
\hfill
%b)
- \includegraphics[height=\fh]{emoraye_touchpad-menu}
- \hfill
%c)
\includegraphics[height=\fh]{emoraye_touchpad-gesture}
\hfill
%d)
\includegraphics[height=\fh]{emoraye_rmw}
\label{fig:faceexpressions}
- \caption[Avatar face expression selection techniques in VR.]{Four of the face expression selection techniques: raycasting 2D grid menu, 2D circular menu arranged by emotion, touchpad gestures, raycasting on the 2D circular menu arranged by emotion.
+ \caption[Avatar face expression selection techniques in VR.]{Four of the face expression selection techniques: 2D circular menu arranged by emotion, raycasting 2D grid menu, touchpad gestures, raycasting on the 2D circular menu arranged by emotion.
%designed:
%a) menu presents a grid menu in front of the user with raycasting used to select an expression,
%b) touchpad presents a circular menu above the controller and selection is made using the controller's touchpad,
}
\end{figure}
-The visual representation of face expressions in our techniques essentially use emojis.
-We made this choice because people use them frequently in messaging and social networks.
-Also, they are designed to be recognized even with a small size.
-Some of them represent emotions.
+The visual representation of face expressions in our techniques use emojis.
+We made this choice because they are frequently used in messaging and social networks.
+Also, people can identify them even with a small size.
+%Some of them represent emotions.
If we restrict face expressions corresponding to emotions, we can leverage models of emotions such as PAD \cite{mehrabian96} or Plutchik's wheel of emotions \cite{plutchik01}.
-The layout of one of the face expression selection techniques we proposed is adapted from Plutchik's wheel, which organizes emotions along 8 axes representing 8 base emotions.
+The layout of our pie menu selection technique is adapted from Plutchik's wheel, which organizes emotions along 8 axes representing 8 base emotions.
The difference between Plutchik's wheel and our menu is that we mapped the maximum intensity to the edge of the circle rather than to the middle so that the center represents the neutral face.
The grid menu allows the selection of any face expression, regardless if they represent an emotion or not.
In particular users can select emojis with decorations such as hearts, tears, or glasses for example.
In this case we render these decorations on top of the avatar's face.
Transitions between two face expressions are made by interpolating the values of each FACS action unit.
-
+Our evaluations show that participants made more errors with the gesture and voice techniques, and they prefered the other techniques.
%The the layout of the circular menu is based on Plutchik's wheel of emotions \cite{plutchik01}.
We designed several techniques for controlling the intensity, duration, and ending of face expressions all at once.
+Users define the duration indirectly when they end the face expression.
The first technique maps the intensity to the controller trigger.
+The face expression ends $1s$ after the user released the trigger to avoid incidental endings.
+The other techniques below end when the user releases the selection button.
+%This method is not convenient with the gesture and voice selection techniques because it adds another step, contrary to the other techniques that already use a validation action.
With the second technique, users have to shake the controller and the intensity is mapped to the shaking speed.
The third technique is similar, users must roll the controller and the intensity is mapped to the roll angle.
-The fourth technique draws a
-elastic
-touchpad position
+%Participants of our experiments had poor performance with these two methods.
+The fourth technique creates a visible elastic band between the selected expression and the selection ray.
+The intensity is mapped to the length of the elastic band.
+This technique requires a ray to which the elastic band is attached, therefore it cannot be used with a subset ot the face expression selection techniques.
+The last technique only work with pie menu techniques, and map the intensity to the distance to the center of the menu.
+Our evaluations show a subjective preference of the elastic band, trigger, and orientation techniques over the shake technique.
+
+We evaluated the usability of the pie menu with a raycasting selection and an intensity control with the elastic band.
+The results show that controlling their avatar's face expression can disturb users while they are talking or listening to somebody else.
+However, the perceived interruptions were reasonnable.
+
\subsubsection{Discussion}
projects / hdr.git / commitdiff