Development of a Virtual Object Weight Recognition Algorithm Based on Pseudo-Haptics and the Development of Immersion Evaluation Technology
Round 1
Reviewer 1 Report
The study propose a Pseudo-Haptic-based user-customized virtual object weight recognition algorithm using natural hand tracking and visual illusion effects only with cameras in VR headsets.. Overall, the paper is well-written and innovative. However, I think the authors need to address the following comments before being published.
1）The authors stated that they produce pseudo-haptic and simulation contents based on visual illusion effects, what do you mean by using “visual illusion effects”?
2) The weights of the density, volume, and speed of the virtual object may be different for various users, which rely on their real-life experience and immersion experience. How to achieve the user-customized virtual object weight recognition?
3) The two experiments are interesting. Please explain the questionnaire design method and how to choose the right questions?
4) What is the main contribution(s) of the proposed approach? The contributions should be stated explicitly.
Author Response
1. The authors stated that they produce pseudo-haptic and simulation contents based on visual illusion effects, what do you mean by using “visual illusion effects”?
→ Visual illusion effect means that using the algorithm developed in this paper, decoupling of the user's hand position in XR content and the user's hand position in real space creates a visual illusion that makes the actual hand position different from that shown to the real user.
→ Line 75-78
2. The weights of the density, volume, and speed of the virtual object may be different for various users, which rely on their real-life experience and immersion experience. How to achieve the user-customized virtual object weight recognition?
→ Line 92~94
→ In this paper, the density and volume contents are removed and reflected
3. The two experiments are interesting. Please explain the questionnaire design method and how to choose the right questions?
→ Line 399~428
→ 5. Questionnaire development
4. What is the main contribution(s) of the proposed approach? The contributions should be stated explicitly.
→ Line 75~82, Line 534~539
→ Visual illusion effect means that using the algorithm developed in this paper, decoupling of the user's hand position in XR content and the user's hand position in real space creates a visual illusion that makes the actual hand position different from that shown to the real user. We expect that this study will provide algorithms and pilot contents for Pseudo-Haptic technology based on the experimental visual illusion effect, which can lead to the implementation of more detailed research in the area, and contribute to the development of cultural content industry based on increased immersion.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
1. In the two parts of introduction and related work, the introduction of related technologies is insufficient, lacking scope and depth. In addition, it does not explain the problems or bottlenecks faced by the current virtual object weight measurement technology, so it does not highlight the difference and progressiveness between the algorithm proposed in this paper and the existing technology.
2. The variables Wvirtual, Fvirtual and Vvirtual in Figure 1 are not explained in the picture description or in the previous text.
3. In this paper, the weight of the virtual object is reflected by setting the moving distance of the object in the virtual space, but the offset between the virtual hand and the object may lose some authenticity and weaken the sense of immersion. If the virtual hand can adaptively move with the currently lifted object, but still keep the heavy object moving slowly (or at a short distance) and the light object moving fast (or at a long distance), this should help to improve the sense of immersion.
4. Formula 3 has numerical error.
5. please check formulas (4) and (5) to ensure that the variables represented are correct. Because force * velocity equals power. In addition, some customized formulas are not explained in detail, such as formulas (4) and (5).
6. In this paper, the volume of the object is considered in the algorithm, but in the calculation process, the volume is to multiply the density to calculate the gravity, and the gravity is a quantity that must be obtained, and can even be considered as a known quantity, so it seems redundant to consider the volume and density.
Author Response
We would first like to thank the reviewer for the comments which have helped us improve our study in many ways.
Since the online system do not allow us to upload several files, we wrote brief answers for the comments from the reviewer and indicated where we have applied our improvements according to the review.
Please see the attached full paper.
Lastly, we would like to mention that we agree with the reviewer's comments and tried our best to improve our work, but the given time was sadly short and would like to improve our work more in the next paper.
Thank you.
- In the two parts of introduction and related work, the introduction of related technologies is insufficient, lacking scope and depth. In addition, it does not explain the problems or bottlenecks faced by the current virtual object weight measurement technology, so it does not highlight the difference and progressiveness between the algorithm proposed in this paper and the existing technology.
→ Line 100~144
→ We have improved our "Related work" and supplement part of the paper.
2. The variables W_virtual, F_virtual and V_virtual in Figure 1 are not explained in the picture description or in the previous text.
→ Line 162~192
→ We have modified the title of Figure 1, and added a description
3. In this paper, the weight of the virtual object is reflected by setting the moving distance of the object in the virtual space, but the offset between the virtual hand and the object may lose some authenticity and weaken the sense of immersion. If the virtual hand can adaptively move with the currently lifted object, but still keep the heavy object moving slowly (or at a short distance) and the light object moving fast (or at a long distance), this should help to improve the sense of immersion.
→ Line 273~278
→ We have suggested a correction plan to the opinion that offset between virtual hands and objects can lose authenticity and interfere with immersion.
4. Formula 3 has numerical error.
→ In Equation (2)
→ Modification complete.
5. Please check formulas (4) and (5) to ensure that the variables represented are correct. Because force * velocity equals power. In addition, some customized formulas are not explained in detail, such as formulas (4) and (5).
→ In Equation (3), Line 229~278
→ Cleaned up force-related errors and re-established the algorithm.
6. In this paper, the volume of the object is considered in the algorithm, but in the calculation process, the volume is to multiply the density to calculate the gravity, and the gravity is a quantity that must be obtained, and can even be considered as a known quantity, so it seems redundant to consider the volume and density.
→ Line 12~15
→ We have modified the content considering the density and volume proposed in this paper (modified the overall content of the paper).
Author Response File: Author Response.pdf
Reviewer 3 Report
Thank you for your interesting research.
The implemented methods apply only to lifting the object in one of the axes, while the awareness of the object's weight during immersion is influenced by the behavior of the action of individual forces when the object moves in the entire space. Paper describes the basic methods that can lead to the implementation of more detailed research in this area.
In the paper, it is not entirely clear whether the same environment and force calculation settings are used for individual test participants depending on the speed of hand movement, or whether the measurement of basic parameters is individualized for each user, as you state in chapter 3. Individualization can have case a big impact on the degree of immersion.
Remarks:
Missing references in the text for Figures 2,3,5,6,7
In Figure 1 description, please use correct order a,b,c, not b,a,c
In the text, give references to the cited literature before the full stop at the end of the sentence.
Line 428 - replace word "intoxication" by another word
Line 471 - missing Author contribution - please fill your contribution based on the template
Line 479 - missing Acknowledgments - if no Ack. please delete this part
Author Response
We would first like to thank the reviewer for the comments which have helped us improve our study in many ways.
Since the online system do not allow us to upload several files, we wrote brief answers for the comments from the reviewer and indicated where we have applied our improvements according to the review.
Please see the attached full paper.
Lastly, we would like to mention that we agree with the reviewer's comments and tried our best to improve our work, but the given time was sadly short and would like to improve our work more in the next paper.
Thank you.
1. The implemented methods apply only to lifting the object in one of the axes, while the awareness of the object's weight during immersion is influenced by the behavior of the action of individual forces when the object moves in the entire space. Paper describes the basic methods that can lead to the implementation of more detailed research in this area.
→ Line 577~582
→ We agree and have left comments on limitations in the study and left it as a future study plan.
2. In the paper, it is not entirely clear whether the same environment and force calculation settings are used for individual test participants depending on the speed of hand movement, or whether the measurement of basic parameters is individualized for each user, as you state in chapter 3. Individualization can have case a big impact on the degree of immersion.
→ Line 444~449, 497~501
→ Added a premise for customized Force in Experiment1 and 2.
3. Remarks:
→ Modification complete
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
There are no further comments or suggestions. However, there is an idea that whether only using speed difference to reflect the weight of the virtual object can help improve the sense of immersion. That is, the offset caused by the speed difference only appears in the moving process, and when the virtual hand stops moving, the virtual object will slowly move to the position of the virtual hand.
