Complete comments

5-conclusion/conclusion.tex

@@ -65,10 +65,10 @@ This only allowed us to estimate poses of the index finger and the surface to be
 In fact, preliminary tests we conducted showed that the built-in tracking capabilities of the HoloLens~2 were not able to track hands wearing a vibrotactile voice-coil device.
 A more robust hand pose estimation system would support wearing haptic devices on the hand as well as holding real objects.
 
-\comans{JG}{I [...] also want to highlight the opportunity to study the effect of visual registration error as noted already in chapter 4.}{Sentences along these lines has been added.}
-The spatial registration error \cite{grubert2018survey} and the temporal latency \cite{diluca2019perceptual} between the real and the virtual content should also be reduced to be imperceptible.
-The effect of these spatial and temporal errors on the perception and manipulation of the virtual content should be systematically investigated.
+The spatial registration error \cite{grubert2018survey} and the temporal latency \cite{diluca2019perceptual} between the \RE and \VE should also be reduced to be imperceptible.
+The effect of these spatial and temporal errors on the perception and manipulation of the virtual object should be systematically investigated.
 Prediction of hand movements should also be considered to overcome such issues \cite{klein2020predicting,gamage2021predictable}.
+\comans{JG}{I [...] also want to highlight the opportunity to study the effect of visual registration error as noted already in chapter 4.}{Sentences along these lines has been added.}
 
 A complementary solution would be to embed tracking sensors in the wearable haptic devices, such as an inertial measurement unit (IMU) or cameras \cite{preechayasomboon2021haplets}.
 This would allow a complete portable and wearable visuo-haptic system to be used in practical applications.
@@ -98,34 +98,30 @@ 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.
-The role of visuo-haptic texture augmentation 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 printed object before it is manufactured.
+A real surface could be indeed augmented not only to add visuo-haptic textures, but also to amplify, diminish, mask, or replace the existing real texture.
+\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}{This has been better discussed.}
+In addition, the visual textures used were simple color images not intended for use in an \ThreeD \VE, and enhancing their visual quality could improve the perception of visuo-haptic texture augmentation.
 \comans{JG}{As future work, the effect of visual quality of the rendered textures on texture perception could also be of interest.}{A sentence along these lines has been added.}
-Finally, the visual textures used were simple color images not intended for use in an \ThreeD \VE, and enhancing their visual quality could improve the perception of visuo-haptic texture augmentation.
+It would also be interesting to replicate the experiment in more controlled visuo-haptic environments, in \VR or with world-grounded haptic devices.
+This would enable to better understand how the rendering quality, spatial registration and latency of virtual textures can affect their perception.
+\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.}{This has been added.}
+Finally, the role of visuo-haptic texture augmentation 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 printed object before it is manufactured.
 
 \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.
+The haptic textures used were recordings and models of the vibrations of a hand-held probe sliding over real surfaces \cite{culbertson2014one}.
 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}.
 It would be interesting to determine the importance of these factors on the perceived realism of virtual vibrotactile textures in the context of bare finger touch.
 Finger based captures of real textures should also be considered \cite{balasubramanian2024sens3}.
 Finally, the virtual texture models should also be adaptable to individual sensitivities \cite{malvezzi2021design,young2020compensating}.
+\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.}{This has been discussed more in depth in this section.}
 
 \subsection*{Visual Augmentation of the Hand for Manipulating virtual objects in AR}
 
-\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.}{This has been discussed more in depth in this section.}
-
-\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.}{This has been discussed more in depth in this section.}
-
 \paragraph{Other AR Displays.}
 
 The visual hand augmentations we evaluated were displayed on the Microsoft HoloLens~2, which is a common \OST-\AR headset \cite{hertel2021taxonomy}.
@@ -135,6 +131,7 @@ However, the user's visual perception and experience are different with other ty
 In particular, the mutual occlusion problem and the latency of hand pose estimation  could be overcome with a \VST-\AR headset.
 In this case, the occlusion rendering could be the most natural, realistic and effective augmentation.
 Yet, a visual hand augmentation could still be beneficial to users by providing depth cues and feedback on hand tracking, and should be evaluated as such.
+\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.}{This has been discussed more in depth in this section.}
 
 \paragraph{More Practical Usages.}
 
@@ -143,6 +140,7 @@ These tasks are indeed fundamental building blocks for more complex manipulation
 They can indeed require users to perform more complex finger movements and interactions with the virtual object.
 Depending on the task, the importance of position, orientation and depth information of the hand and the object may vary and affect the choice of visual hand augmentation.
 More practical applications should also be considered, such as medical, educational or industrial scenarios, which may have different needs and constraints (\eg, the most natural visual hand augmentation for a medical application, or the easiest to understand and use for an educational context).
+\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.}{This has been discussed more in depth in this section.}
 
 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.
 Finally, all visual hand augmentations received low and high rank rates from different participants, suggesting that users should be able to choose and personalize some aspects of the visual hand augmentation according to their preferences or needs, and this should also be evaluated.