WIP xr-perception

2-perception/vhar-system/1-introduction.tex

@@ -1,20 +1,17 @@
 % Even before manipulating a visual representation to induce a haptic sensation, shifts and latencies between user input and co-localised visuo-haptic feedback can be experienced differently in \AR and \VR, which we aim to investigate in this work.
 
-%Imagine you're an archaeologist or in a museum, and you want to examine an ancient object.
-%
-%But it is too fragile to touch directly.
-%
-%What if you could still grasp it and manipulate it through a tangible object in your hand, whose visual appearance has been modified using Augmented Reality (AR)?
-%
-%And what if you could also feel its shape or texture?
-%
-%Such tactile augmentation is made possible by wearable haptic devices, which are worn directly on the finger or hand and can provide a variety of sensations on the skin, while being small, light and discreet \cite{pacchierotti2017wearable}.
-%
-Wearable haptic devices, worn directly on the finger or hand, have been used to render a variety of tactile sensations to virtual objects seen in \VR \cite{choi2018claw,detinguy2018enhancing,pezent2019tasbi} or \AR \cite{maisto2017evaluation,meli2018combining,teng2021touch}.
+Wearable haptic devices have proven to be effective in modifying the perception of a touched tangible surface, without modifying the tangible, nor covering the fingertip, forming a haptic \AE \cite{bau2012revel,detinguy2018enhancing,salazar2020altering}.
+
+Second, many works have investigated the haptic augmentation of textures, but few have integrated them with immersive \VEs or have considered the influence of the visual rendering on their perception.
+Still, it is known that the visual feedback can alter the perception of real and virtual haptic sensations \cite{schwind2018touch,choi2021augmenting} but also that the force feedback perception of grounded haptic devices is not the same in \AR and \VR \cite{diluca2011effects,gaffary2017ar}.
+
+% Insist on the advantage of wearable : augment any surface see bau2012revel
+
+Wearable haptic devices, worn directly on the finger or hand, have been used to render a variety of tactile sensations to \VOs seen in \VR \cite{choi2018claw,detinguy2018enhancing,pezent2019tasbi} or \AR \cite{maisto2017evaluation,meli2018combining,teng2021touch}.
 %
 They have also been used to alter the perception of roughness, stiffness, friction, and local shape perception of real tangible objects \cite{asano2015vibrotactile,detinguy2018enhancing,salazar2020altering}.
 %
-Such techniques place the actuator \emph{close} to the point of contact with the real environment, leaving the user free to directly touch the tangible.
+Such techniques place the actuator \emph{close} to the point of contact with the \RE, leaving the user free to directly touch the tangible.
 %
 This combined use of wearable haptics with tangible objects enables a haptic \emph{augmented} reality (HAR) \cite{bhatia2024augmenting} that can provide a rich and varied haptic feedback.
 
@@ -22,7 +19,7 @@ The degree of reality/virtuality in both visual and haptic sensory modalities ca
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 Although \AR and \VR are closely related, they have significant differences that can affect the user experience \cite{genay2021virtual,macedo2023occlusion}.
 %
-%By integrating visual virtual content into the real environment, \AR keeps the hand of the user, the haptic devices worn and the tangibles touched visible, unlike \VR where they are hidden by immersing the user into a visual virtual environment.
+%By integrating visual virtual content into the \RE, \AR keeps the hand of the user, the haptic devices worn and the tangibles touched visible, unlike \VR where they are hidden by immersing the user into a visual virtual environment.
 %
 %Current \AR systems also suffer from display and rendering limitations not present in \VR, affecting the user experience with virtual content that may be less realistic or inconsistent with the real augmented environment \cite{kim2018revisiting,macedo2023occlusion}.
 %
@@ -40,13 +37,15 @@ We focus on the perception of roughness, one of the main tactile sensations of m
 %
 By understanding how these 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.
 
-Our contributions are:
-%
+\noindentskip The contributions of this chapter are:
 \begin{itemize}
-  \item A system for rendering virtual vibrotactile roughness textures in real time on a tangible surface touched directly with the finger, integrated with an immersive visual AR/VR headset to provide a coherent multimodal visuo-haptic augmentation of the real environment.
-  \item A psychophysical study with 20 participants to evaluate the perception of these virtual roughness textures in three visual rendering conditions: without visual augmentation, with a realistic virtual hand rendering in \AR, and with the same virtual hand in \VR.
+  \item The rendering of virtual vibrotactile roughness textures in real time using webcam to track the finger touching.
+  \item A system to provide a coherent multimodal visuo-haptic texture augmentations of the \RE in direct touch context using an immersive visual AR/VR headset and wearable haptics.
 \end{itemize}
-%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 real environment.
+
+\noindentskip In the remainder of this chapter, we describe the principles of the system, how the real and virtual environments are registered, the generation of the vibrotactile textures, and measures of visual and haptic rendering latencies.
+
+%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.
 %