From 68bd7925836cba7451a89cf642e74967946940d5 Mon Sep 17 00:00:00 2001 From: Erwan Normand Date: Thu, 17 Apr 2025 17:43:21 +0200 Subject: [PATCH] Add remaining report comments --- 1-introduction/introduction.tex | 4 ++++ 3-perception/vhar-system/2-method.tex | 6 ++++++ 4-manipulation/visual-hand/5-conclusion.tex | 4 +++- 4-manipulation/visuo-haptic-hand/1-introduction.tex | 3 +++ 4-manipulation/visuo-haptic-hand/5-conclusion.tex | 2 ++ 5-conclusion/conclusion.tex | 8 ++++++++ config/content.tex | 2 +- 7 files changed, 27 insertions(+), 2 deletions(-) diff --git a/1-introduction/introduction.tex b/1-introduction/introduction.tex index 8ea4d5d..cf2646f 100644 --- a/1-introduction/introduction.tex +++ b/1-introduction/introduction.tex @@ -123,6 +123,8 @@ The \textbf{integration of wearable haptics with \AR headsets appears to be one \section{Research Challenges of Wearable Visuo-Haptic Augmented Reality} \label{research_challenges} +\comans{SJ}{The chapter could benefit from some expansion. For instance, the current introduction tries to describe the scope of the research in haptic AR but lacks sufficient background on the general issues in this domain. As a result, it may not be very helpful for readers unfamiliar with the field in understanding the significance of the thesis's focus and positioning it within the broader context of haptic AR research.}{TODO} + The integration of wearable haptics with \AR headsets to create a visuo-haptic \AE is complex and presents many perceptual and interaction challenges. In this thesis, we propose to \textbf{represent the user's experience with such a visuo-haptic \AE as an interaction loop}, shown in \figref{interaction-loop}. It is based on the interaction loops of users with \ThreeD systems \cite[p.84]{laviolajr20173d}. @@ -140,6 +142,8 @@ In this context, we focus on two main research challenges: \textbf{(I) providing plausible and coherent visuo-haptic augmentations}, and \textbf{(II) enabling effective manipulation of the \AE}. Each of these challenges also raises numerous design, technical, perceptual and user experience issues specific to wearable haptics and \AR headsets. +\comans{JG}{While these research axes seem valid, it could have been described more clearly how they fit into the overarching research fields of visuo-haptic augmentations.}{TODO} + \footnotetext{% The icons are \href{https://creativecommons.org/licenses/by/3.0/}{CC BY} licensed: \enquote{\href{https://thenounproject.com/icon/finger-pointing-4230346/}{finger pointing}} by \href{https://thenounproject.com/creator/leremy/}{Gan Khoon Lay}, diff --git a/3-perception/vhar-system/2-method.tex b/3-perception/vhar-system/2-method.tex index 49fce30..04ed69f 100644 --- a/3-perception/vhar-system/2-method.tex +++ b/3-perception/vhar-system/2-method.tex @@ -1,6 +1,8 @@ \section{Concept} \label{principle} +\comans{SJ}{The rationale behind the proposed design is not provided. Since there are multiple ways to implement mechanically transparent haptic devices, the thesis should at least clarify why this design is considered optimal for a specific purpose at this stage.}{TODO} + The visuo-haptic texture rendering system is based on: \begin{enumerate}[label=(\arabic*)] \item a real-time interaction loop between the finger movements and a coherent visuo-haptic feedback simulating the sensation of a touched texture, @@ -125,3 +127,7 @@ The total visual latency can be considered slightly high, yet it is typical for The two filters also introduce a constant lag between the finger movement and the estimated position and velocity, measured at \qty{160 \pm 30}{\ms}. With respect to the real hand position, it causes a distance error in the displayed virtual hand position, and thus a delay in the triggering of the vibrotactile signal. This is proportional to the speed of the finger, \eg distance error is \qty{1.2 \pm .2}{\cm} when the finger moves at \qty{7.5}{\cm\per\second}. + +The velocity estimation and delay effects should be examined in more detail, as these +factors are critical for ensuring the perceptual quality of the system. A 36 ms discrepancy +between movement and feedback may not be sufficient in all scenarios. diff --git a/4-manipulation/visual-hand/5-conclusion.tex b/4-manipulation/visual-hand/5-conclusion.tex index 4fa7434..7835fca 100644 --- a/4-manipulation/visual-hand/5-conclusion.tex +++ b/4-manipulation/visual-hand/5-conclusion.tex @@ -11,7 +11,9 @@ Our results showed that a visual hand augmentation improved the performance, per A skeleton rendering, which provided a detailed view of the tracked joints and phalanges while not hiding the real hand, was the most performant and effective. The contour and mesh renderings were found to mask the real hand, while the tips rendering was controversial. The occlusion rendering had too much tracking latency to be effective. -This is consistent with similar manipulation studies in \VR and in non-immersive \VST-\AR setups. +This is consistent with similar manipulation studies in \VR and in \VST-\AR setups. + +\comans{SJ}{According to the results, occlusion is the most natural (in terms of realism) but least efficient for manipulation. In some cases, natural visualization is necessary. It would be beneficial to discuss these cases to help guide AR interaction designers in choosing the most appropriate visualization methods.}{TODO} This study suggests that a \ThreeD visual hand augmentation is important in \AR when interacting with a virtual hand technique, particularly when it involves precise finger movements in relation to virtual content, \eg \ThreeD windows, buttons and sliders, or more complex tasks, such as stacking or assembly. A minimal but detailed rendering of the virtual hand that does not hide the real hand, such as the skeleton rendering we evaluated, seems to be the best compromise between the richness and effectiveness of the feedback. diff --git a/4-manipulation/visuo-haptic-hand/1-introduction.tex b/4-manipulation/visuo-haptic-hand/1-introduction.tex index 3a63708..bbd8e37 100644 --- a/4-manipulation/visuo-haptic-hand/1-introduction.tex +++ b/4-manipulation/visuo-haptic-hand/1-introduction.tex @@ -1,6 +1,9 @@ \section{Introduction} \label{intro} +\comans{SJ}{It is not entirely clear why this experiment is being conducted in an AR environment, considering both the purpose of the experiment and the +controllability of the setup.}{TODO} + Providing haptic feedback during free-hand manipulation in \AR is not a trivial issue, as wearing haptic devices on the hand might affect the tracking capabilities of the system \cite{pacchierotti2016hring}. Moreover, it is important to leave the user capable of interacting with both virtual and real objects, avoiding the use of haptic interfaces that cover the fingertips or palm. For this reason, it is often considered beneficial to move the point of application of the haptic feedback elsewhere on the hand (\secref[related_work]{vhar_haptics}). diff --git a/4-manipulation/visuo-haptic-hand/5-conclusion.tex b/4-manipulation/visuo-haptic-hand/5-conclusion.tex index 3927401..ac00af2 100644 --- a/4-manipulation/visuo-haptic-hand/5-conclusion.tex +++ b/4-manipulation/visuo-haptic-hand/5-conclusion.tex @@ -11,6 +11,8 @@ However, the farthest positioning on the contralateral hand gave the best perfor The visual hand augmentation was perceived less necessary than the vibrotactile haptic feedback, but still provided a useful feedback on the hand tracking. This study provide evidence that moving away the feedback from the inside of the hand is a simple but promising approach for wearable haptics in \AR. +\comans{SJ}{Again, it would strengthen the thesis if the authors provided a systematic guideline on how to choose the appropriate haptic feedback or visual augmentation depending on the specific requirements of an application.}{TODO} + If integration with the hand tracking system allows it, and if the task requires it, a haptic ring worn on the middle or proximal phalanx seems preferable. However, a wrist-mounted haptic device will be able to provide richer feedback by embedding more diverse haptic actuators with larger bandwidths and maximum amplitudes, while being less obtrusive than a ring. Finally, we think that the visual hand augmentation complements the haptic contact rendering well by providing continuous feedback on the hand tracking, and that it can be disabled during the grasping phase to avoid redundancy with the haptic feedback of the contact with the virtual object. diff --git a/5-conclusion/conclusion.tex b/5-conclusion/conclusion.tex index 985fb3b..1024d85 100644 --- a/5-conclusion/conclusion.tex +++ b/5-conclusion/conclusion.tex @@ -98,6 +98,10 @@ The dynamic response of the finger should also be considered, and may vary betwe \paragraph{Applicability of the Method.} +\comans{SJ}{Moreover, if we only consider the experimental findings, the system could likely be recreated using VR or conventional visuo-haptic setups in a more stable manner. It would be beneficial to emphasize how the experiment is closely tied to the specific domain of haptic AR.}{TODO} + +\comans{SJ}{It would be valuable to explore how real texture from a physical surface could be combined with virtual texture, enabling merged, augmented, amplified, or diminished feedback}{TODO} + As in the previous chapter, our aim was not to accurately reproduce real textures, but to alter the perception of a real surface being touched with simultaneous visual and haptic texture augmentations. However, the results also have some limitations, as they addressed a small set of visuo-haptic textures that augmented the perception of smooth and white real surfaces. Visuo-haptic texture augmentation might be difficult on surfaces that already have strong visual or haptic patterns \cite{asano2012vibrotactile}, or on objects with complex shapes. @@ -107,6 +111,8 @@ Finally, the visual textures used were simple color images not intended for use \paragraph{Specificities of Direct Touch.} +\comans{SJ}{Technical concern: As far as I know, the texture rendering algorithm from [Curbertson et al.] is based on rigid-tool-based interactions. The vibration patterns due to texture in a bare-hand interaction scenario (used in this study) should differ significantly from those produced in rigid-tool interactions. I conduct similar research and am confident that the signals involved in bare-hand interactions are far more complex than those in rigid-tool-based interactions. Therefore, the choice of rendering algorithm could negatively affect the experimental results. This issue is critical and should either be revised or extensively discussed in the thesis.}{TODO} + The haptic textures used were recordings and models of the vibrations of a hand-held probe sliding over real surfaces. We generated the vibrotactile textures from velocity magnitude of the finger, but the perceived roughness of real textures also depends on other factors such as the contact force, angle, posture or surface of the contact \cite{schafer2017transfer}. The respective importance of these factors on the haptic texture perception is not yet fully understood \cite{richardson2022learning}. @@ -126,6 +132,8 @@ While the mutual occlusion problem and the hand pose estimation latency could be \paragraph{More Practical Usages.} +\comans{SJ}{The task in the experiment is too basic, making it difficult to generalize the results. There are scenarios where depth information may be more important than position, or where positioning may be more critical than orientation. A systematic categorization and analysis of such cases would add depth to the chapter.}{TODO} + We conducted the user study with two manipulation tasks that involved placing a virtual cube in a target volume, either by pushing it on a table or by grasping and lifting it. These tasks are indeed fundamental building blocks for more complex manipulation tasks \cite[p.390]{laviolajr20173d}, such as stacking or assembly, which should also be considered. %, more ecological applications should be considered. Similarly, a broader experimental study might shed light on the role of gender and age, as our subject pool was not sufficiently diverse in this regard. diff --git a/config/content.tex b/config/content.tex index 7e076fa..c73d910 100644 --- a/config/content.tex +++ b/config/content.tex @@ -1,7 +1,7 @@ % Changes \usepackage[commentmarkup=footnote]{changes} \definechangesauthor[name=Jens Grubert, color=Dandelion]{JG} -\definechangesauthor[name=Seokhee Jeon, color=Red]{SG} +\definechangesauthor[name=Seokhee Jeon, color=Red]{SJ} \newcommand{\comans}[3]{% \comment[id=#1]{% #2\\%