From 8bf1ad6fb7eb39d410b68682eb7d80db00c31e7d Mon Sep 17 00:00:00 2001 From: Erwan Normand Date: Mon, 30 Sep 2024 09:03:27 +0200 Subject: [PATCH] Complete future works --- 4-conclusion/conclusion.tex | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-) diff --git a/4-conclusion/conclusion.tex b/4-conclusion/conclusion.tex index cd16162..4dfbc92 100644 --- a/4-conclusion/conclusion.tex +++ b/4-conclusion/conclusion.tex @@ -52,8 +52,8 @@ In this section, we present some future work for each chapter that could address \paragraph{Other Augmented Object Properties} We focused on the visuo-haptic augmentation of roughness using vibrotactile feedback, because it is one of the most salient properties of surfaces (\secref[related_work]{object_properties}), one of the most studied in haptic perception (\secref[related_work]{texture_rendering}), and equally perceived by sight and touch (\secref[related_work]{visual_haptic_influence}). -However, many other wearable augmentation of object properties could be considered, such as hardness, friction, temperature, or local deformations. -Such integration of haptic augmentation of a tangible surface has almost been achieved with the hand-held devices of \citeauthor{culbertson2017ungrounded} \cite{culbertson2017importance,culbertson2017ungrounded}, but it remains to be explored with wearable haptic devices. +However, many other wearable augmentation of object properties should be considered, such as hardness, friction, temperature, or local deformations. +Such integration of haptic augmentation of a tangible surface has almost been achieved with the hand-held devices of \citeauthor{culbertson2017ungrounded} \cite{culbertson2017importance,culbertson2017ungrounded}, but will be more challenging with wearable haptic devices. In addition, combination with pseudo-haptic rendering techniques \cite{ujitoko2021survey} should be systematically investigated to expand the range of possible wearable haptic augmentations. \paragraph{Fully Integrated Tracking} @@ -69,9 +69,9 @@ This would allow a complete portable and wearable visuo-haptic system to be used \paragraph{Visual Representation of the Virtual Texture} -The main limitation of this user study was the absence of a visual representation of the virtual texture. +The main limitation of this user study was the absence of a visual representation of the virtual patterned texture. This is indeed a source of information as important as haptic sensations for the perception of both real textures \cite{baumgartner2013visual,bergmanntiest2007haptic,vardar2019fingertip} and virtual textures \cite{degraen2019enhancing,gunther2022smooth}, and their interaction in the overall perception is complex. -Specifically, it remains to be investigated how to visually represent the vibrotactile patterned textures used in an immersive \AR or \VR context, as the visuo-haptic coupling of such patterned textures is not trivial \cite{unger2011roughness} even with real textures \cite{klatzky2003feeling}. +Specifically, it remains to be investigated how to visually represent the vibrotactile patterned textures in a way that is compelling, as the visuo-haptic coupling of such patterned textures is not trivial \cite{unger2011roughness}.% even with real textures \cite{klatzky2003feeling}. \paragraph{Broader Visuo-Haptic Conditions} @@ -79,23 +79,25 @@ Our study was conducted with an \OST-\AR headset, but the results may be differe We also focused on the perception of roughness augmentation using wearable vibrotactile haptics and a square wave signal to simulate a patterned texture: Our objective was not to accurately reproduce real textures, but to induce various roughness perception on the same tangible surface with a well controlled parameters. Yet, more accurate models to simulate interaction with virtual textures should be transposed to wearable haptic augmentations, such as in \textcite{unger2011roughness}. Another limitation that may have affected the perception of the haptic texture augmentations is the lack of compensation for the frequency response of the actuator and amplifier \cite{asano2012vibrotactile,culbertson2014modeling,friesen2024perceived}. -The dynamic response of the finger should also be considered. +The dynamic response of the finger should also be considered, and could vary among individuals. \subsection*{Perception of Visual and Haptic Texture Augmentations in Augmented Reality} +\paragraph{Assess the Applicability of the Method} + +As with the previous chapter, our objective was not to accurately reproduce real textures, but to alter the perception of a tangible surface being touched with simultaneous visual and haptic texture augmentations. +Yet, the results have also some limitations as they addressed a small set of visuo-haptic textures augmenting the perception of smooth and white tangible surfaces. +The visuo-haptic texture augmentation may be difficult on surfaces that already have strong visual or haptic patterns \cite{asano2012vibrotactile}, or on objects with complex shapes. +The role of visuo-haptic texture augmentations should also be evaluated in more complex tasks, such as object recognition and assembly, or in more concrete use cases, such as displaying and touching a museum object or a 3D print before manufacturing it. + +%Finally, the visual textures used were also simple color captures not meant to be used in an immersive \VE. + \paragraph{Adapt to the Specificities of Direct Touch} -As with the previous chapter, our objective was not to accurately reproduce real textures, but to alter the perception of simultaneous visual and haptic roughness augmentation of a tangible surface directly touched by the finger in \AR. -Yet, the haptic textures used models from the vibrations of a hand-held probe sliding over real surfaces captured. -We generated the vibrotactile textures based only on the finger speed, but the perceived roughness of real textures depends on other factors, such as the force of contact, the angle, the posture or the surface of the contact \cite{schafer2017transfer}, but their respective importance in the perception is not yet fully understood \cite{richardson2022learning}. -%Comparison from - -These results have of course some limitations as they addressed a small set of visuo-haptic textures augmenting the perception of smooth white tangible surfaces. -Indeed, the increase in visuo-haptic texture perception may be limited on surfaces that already have strong visual or haptic patterns \cite{asano2012vibrotactile}, or on objects with complex shapes. -In addition, the haptic textures used were modelled from the vibrations of a probe sliding over the captured surfaces. -Finally, the visual textures used were also simple color captures not meant to be used in an immersive \VE. -However, -In addition of these limitations, both visual and haptic texture models should be improved by integrating the rendering of spatially localized breaks, edges or patterns, like real textures \cite{richardson2022learning}, and by being adaptable to individual sensitivities, as personalized haptics is a promising approach \cite{malvezzi2021design,young2020compensating}. +The haptic textures used models from the vibrations of a hand-held probe sliding over real surfaces captured. +We generated the vibrotactile textures only from the finger speed \cite{culbertson2015should}, but the perceived roughness of real textures also depends on other factors, such as the force of contact, the angle, the posture or the surface of the contact \cite{schafer2017transfer}, but their respective importance in the perception is not yet fully understood \cite{richardson2022learning}. +It would be interesting to determine the importance of these factors on the perceived realism of virtual vibrotactile textures. +The virtual texture models should also be adaptable to individual sensitivities \cite{malvezzi2021design,young2020compensating}. \subsection*{Visual Rendering of the Hand for Manipulating \VOs in AR} @@ -125,11 +127,10 @@ More importantly, the best compromise between well-round haptic feedback and wea \paragraph{Personalized Haptics} -Some users found the vibration rendering to be too strong, suggesting that adapting and personalizing the haptic feedback to one's preference is a promising approach. +Some users found the vibration rendering to be too strong, suggesting that adapting and personalizing the haptic feedback to one's preference is to investigate \cite{malvezzi2021design, umair2021exploring}. In addition, although it was perceived as more effective and realistic when provided close to the point of contact, other positionings, such as the wrist, may be preferred and still be sufficient for a given task. The interactions in our user study were also restricted to the thumb and index fingertips, with the haptic feedback provided only for these contact points, as these are the most commonly used parts of the hand for manipulation tasks. It remains to be explored how to support rendering for different and larger areas of the hand, and how to position a delocalized rendering for points other than the fingertips could be challenging. -Indeed, personalized haptics is gaining interest in the community \cite{malvezzi2021design, umair2021exploring}. \section{Perspectives}