tangible -> real

2-perception/xr-perception/1-introduction.tex

@@ -1,14 +1,14 @@
 \section{Introduction}
 \label{intro}
 
-Most of the haptic augmentations of tangible surfaces using with wearable haptic devices, including roughness of textures (\secref[related_work]{texture_rendering}), have been studied without a visual feedback, and none have considered the influence of the visual rendering on their perception or integrated them in \AR and \VR (\secref[related_work]{texture_rendering}).
-Still, it is known that the visual rendering of a tangible can influence the perception of its haptic properties (\secref[related_work]{visual_haptic_influence}), and that the perception of same haptic force-feedback or vibrotactile rendering can differ between \AR and \VR, probably due to difference in perceived simultaneity between visual and haptic stimuli (\secref[related_work]{ar_vr_haptic}).
+Most of the haptic augmentations of real surfaces using with wearable haptic devices, including roughness of textures (\secref[related_work]{texture_rendering}), have been studied without a visual feedback, and none have considered the influence of the visual rendering on their perception or integrated them in \AR and \VR (\secref[related_work]{texture_rendering}).
+Still, it is known that the visual rendering of an object can influence the perception of its haptic properties (\secref[related_work]{visual_haptic_influence}), and that the perception of same haptic force-feedback or vibrotactile rendering can differ between \AR and \VR, probably due to difference in perceived simultaneity between visual and haptic stimuli (\secref[related_work]{ar_vr_haptic}).
 Indeed, in \AR, the user can see their own hand touching, the haptic device worn and the \RE, while in \VR they are hidden by the \VE.
 
-In this chapter, we investigate the \textbf{role of the visual virtuality} of the hand (real or virtual) and its environment (\AR or \VR) on the perception of a \textbf{tangible surface whose haptic roughness is augmented} with a wearable haptics. %voice-coil device worn on the finger.
-To do so, we used the visuo-haptic system presented in \chapref{vhar_system} to render virtual vibrotactile patterned textures (\secref[related_work]{texture_rendering}) to augment the tangible surface being touched. % touched by the finger.% that can be directly touched with the bare finger.
+In this chapter, we investigate the \textbf{role of the visual virtuality} of the hand (real or virtual) and its environment (\AR or \VR) on the perception of a \textbf{real surface whose haptic roughness is augmented} with a wearable haptics. %voice-coil device worn on the finger.
+To do so, we used the visuo-haptic system presented in \chapref{vhar_system} to render virtual vibrotactile patterned textures (\secref[related_work]{texture_rendering}) to augment the real surface being touched. % touched by the finger.% that can be directly touched with the bare finger.
 We evaluated, in \textbf{user study with psychophysical methods and extensive questionnaire}, the perceived roughness augmentation in three visual rendering conditions: \textbf{(1) without visual augmentation}, in \textbf{(2) \OST-\AR with a realistic virtual hand} rendering, and in \textbf{(3) \VR with the same virtual hand}.
-To control for the influence of the visual rendering, the tangible surface was not visually augmented and stayed the same in all conditions.
+To control for the influence of the visual rendering, the real surface was not visually augmented and stayed the same in all conditions.
 
 \noindentskip The contributions of this chapter are:
 \begin{itemize}
@@ -21,7 +21,7 @@ We then present the results obtained, discuss them, and outline recommendations
 
 %First, we present a system for rendering virtual vibrotactile textures in real time without constraints on hand movements and integrated with an immersive visual \AR/\VR headset to provide a coherent multimodal visuo-haptic augmentation of the \RE.
 %An experimental setup is then presented to compare haptic roughness augmentation with an optical \AR headset (Microsoft HoloLens~2) that can be transformed into a \VR headset using a cardboard mask.
-%We then conduct a psychophysical study with 20 participants, where various virtual haptic textures on a tangible surface directly touched with the finger are compared in a two-alternative forced choice (2AFC) task in three visual rendering conditions: (1) without visual augmentation, (2) with a realistic virtual hand rendering in \AR, and (3) with the same virtual hand in \VR.
+%We then conduct a psychophysical study with 20 participants, where various virtual haptic textures on a real surface directly touched with the finger are compared in a two-alternative forced choice (2AFC) task in three visual rendering conditions: (1) without visual augmentation, (2) with a realistic virtual hand rendering in \AR, and (3) with the same virtual hand in \VR.
 
 \bigskip
 

2-perception/xr-perception/3-experiment.tex

@@ -1,9 +1,9 @@
 \section{User Study}
 \label{experiment}
 
-%The visuo-haptic rendering system, described in \secref[vhar_system]{method}, allows free exploration of virtual vibrotactile textures on tangible surfaces directly touched with the bare finger to simulate roughness augmentation, while the visual rendering of the hand and environment can be controlled to be in \AR or \VR.
+%The visuo-haptic rendering system, described in \secref[vhar_system]{method}, allows free exploration of virtual vibrotactile textures on real surfaces directly touched with the bare finger to simulate roughness augmentation, while the visual rendering of the hand and environment can be controlled to be in \AR or \VR.
 %
-%The user study aimed to investigate the effect of visual hand rendering in \AR or \VR on the perception of roughness texture augmentation of a touched tangible surface.
+%The user study aimed to investigate the effect of visual hand rendering in \AR or \VR on the perception of roughness texture augmentation of a touched real surface.
 In a \TIFC task (\secref[related_work]{sensations_perception}), participants compared the roughness of different tactile texture augmentations in three visual rendering conditions: without any visual augmentation (\level{Real}, \figref{experiment/real}), in \AR with a realistic virtual hand superimposed on the real hand (\level{Mixed}, \figref{experiment/mixed}), and in \VR with the same virtual hand as an avatar (\level{Virtual}, \figref{experiment/virtual}).
 In order not to influence the perception, as vision is an important source of information and influence for the perception of texture \cite{bergmanntiest2007haptic,yanagisawa2015effects,vardar2019fingertip}, the touched surface was visually a uniform white; thus only the visual aspect of the hand and the surrounding environment is changed.
 
@@ -52,7 +52,7 @@ The user study was held in a quiet room with no windows.
 
 \begin{subfigs}{setup}{Visuo-haptic textures rendering setup. }[][
   \item HoloLens~2 \OST-\AR headset, the two cardboard masks to switch the real or virtual environments with the same field of view, and the \ThreeD-printed piece for attaching the masks to the headset.
-  \item User exploring a virtual vibrotactile texture on a tangible sheet of paper.
+  \item User exploring a virtual vibrotactile texture on a real sheet of paper.
   ]
   \subfigsheight{48.5mm}
   \subfig{experiment/headset}

2-perception/xr-perception/5-discussion.tex

@@ -15,7 +15,7 @@ Thus, compared to no visual rendering (\level{Real}), the addition of a visual r
 Differences in user behaviour were also observed between the visual renderings (but not between the haptic textures).
 On average, participants responded faster (\percent{-16}), explored textures at a greater distance (\percent{+21}) and at a higher speed (\percent{+16}) without visual augmentation (\level{Real} rendering) than in \VR (\level{Virtual} rendering) (\figref{results_finger}).
 The \level{Mixed} rendering was always in between, with no significant difference from the other two.
-This suggests that touching a virtual vibrotactile texture on a tangible surface with a virtual hand in \VR is different from touching it with one's own hand: users were more cautious or less confident in their exploration in \VR.
+This suggests that touching a virtual vibrotactile texture on a real surface with a virtual hand in \VR is different from touching it with one's own hand: users were more cautious or less confident in their exploration in \VR.
 This does not seem to be due to the realism of the virtual hand or the environment, nor to the control of the virtual hand, all of which were rated high to very high by the participants (\secref{results_questions}) in both the \level{Mixed} and \level{Virtual} renderings.
 The evaluation of the vibrotactile device and the textures was also the same between the visual rendering, with a high sense of control, a good realism and a low perceived latency of the textures (\secref{results_questions}).
 Conversely, the perceived latency of the virtual hand (\response{Hand Latency} question) seemed to be related to the perceived roughness of the textures (with the \PSEs).

2-perception/xr-perception/6-conclusion.tex

@@ -2,8 +2,8 @@
 \label{conclusion}
 
 In this chapter, we studied how the perception of wearable haptic augmented textures is affected by the visual virtuality of the hand and the environment, being either real, augmented or virtual.
-Using the wearable visuo-haptic augmentation system presented in \chapref{vhar_system}, we augmented the perceived roughness of tangible surfaces with virtual vibrotactile textures rendered on the finger.
-%we rendered virtual vibrotactile patterned textures on the voice-coil worn on the middle-phalanx of the finger to augment the roughness perception of the tangible surface being touched.
+Using the wearable visuo-haptic augmentation system presented in \chapref{vhar_system}, we augmented the perceived roughness of real surfaces with virtual vibrotactile textures rendered on the finger.
+%we rendered virtual vibrotactile patterned textures on the voice-coil worn on the middle-phalanx of the finger to augment the roughness perception of the real surface being touched.
 With an immersive \AR headset, that could be switched to a \VR only view, we considered three visual rendering conditions: (1) without visual augmentation, (2) with a realistic virtual hand rendering in \AR, and (3) with the same virtual hand in \VR.
 We then evaluated the perceived roughness augmentation in these three visual conditions with a psychophysical user study involving 20 participants and extensive questionnaires.
 
@@ -17,6 +17,6 @@ This study suggests that attention should be paid to the respective latencies of
 Latencies should be measured \cite{friston2014measuring}, minimized to an acceptable level for users and kept synchronised with each other \cite{diluca2019perceptual}.
 It seems also that the visual aspect of the hand or the environment on itself has little effect on the perception of haptic feedback, but the degree of visual reality-virtuality can affect the asynchrony sensation of the latencies, even though they remain identical.
 When designing for wearable haptics or integrating it into \AR/\VR, it seems important to test its perception in real, augmented and virtual environments.
-%With a better understanding of how visual factors influence the perception of haptically augmented tangible objects, the many wearable haptic systems that already exist but have not yet been fully explored with \AR can be better applied and new visuo-haptic renderings adapted to \AR can be designed.
+%With a better understanding of how visual factors influence the perception of haptically augmented real objects, the many wearable haptic systems that already exist but have not yet been fully explored with \AR can be better applied and new visuo-haptic renderings adapted to \AR can be designed.
 %Finally, a visual hand representation in OST-\AR together with wearable haptics should be avoided until acceptable tracking latencies \are achieved, as was also observed for \VO interaction with the bare hand \cite{normand2024visuohaptic}.