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N. Gu, S. Watanabe, H. Erhan, M. Hank Haeusler, W. Huang, R. Sosa (eds.), Rethinking Comprehensive Design: Speculative Counterculture, Proceedings of the 19th International Conference on Computer- Aided Architectural Design Research in Asia CAADRIA 2014, 729–738. © 2014, The Association for Computer-Aided Architectural Design Research in Asia (CAADRIA), Hong Kong IMMERSIVE VIRTUAL ENVIRONMENTS: EXPERIMENTS ON IMPACTING DESIGN AND HUMAN BUILDING INTERACTION ARSALAN HEYDARIAN 1 , JOAO P. CARNEIRO 2 , DAVID GERBER 3 , BURCIN BECERIK-GERBER 4 , TIMOTHY HAYES 5 and WENDY WOOD 6 1,2,3,4 University of Southern California, Los Angeles, United States {heydaria, jcarneir, dgerber, becerik, hayest, wendy.wood}@usc.edu Abstract. This research prefaces the need for engaging with end-users in early stages of design as means to achieve higher performing de- signs with an increased certainty for end-user satisfaction. While the architecture, engineering, and construction (AEC) community has previously used virtual reality, the primary use has been for coordina- tion and visualization of Building Information Models (BIM). This work builds upon the value of use of virtual environments in AEC processes but asks the research question "how can we better test and measure design alternatives through the integration of immersive vir- tual reality into our digital and physical mock up workflows? " The work is predicated on the need for design exploration through associa- tive parametric design models, as well as, testing and measuring de- sign alternatives with human subjects. The paper focuses on immer- sive virtual environments (IVEs) and presents a literature review of the use of virtual environments for integrating end-user feedback dur- ing the design stage. In a controlled pilot experiment, the authors find that human participants perform similarly in IVE and the physical en- vironment in everyday tasks. The participants indicated they felt a strong sense of "presence" in IVE. In the future, the authors plan on using IVE to explore the integration of multi agent systems to impact building design performance and occupant satisfaction. Keywords. Virtual Reality; Prototyping; Design Technology; Immer- sive Virtual Environments; Feedback.

Transcript of immersive virtual environments: experiments on impacting design ...

Page 1: immersive virtual environments: experiments on impacting design ...

N. Gu, S. Watanabe, H. Erhan, M. Hank Haeusler, W. Huang, R. Sosa (eds.), Rethinking Comprehensive Design: Speculative Counterculture, Proceedings of the 19th International Conference on Computer-Aided Architectural Design Research in Asia CAADRIA 2014, 729–738. © 2014, The Association for Computer-Aided Architectural Design Research in Asia (CAADRIA), Hong Kong

IMMERSIVE VIRTUAL ENVIRONMENTS: EXPERIMENTS ON IMPACTING DESIGN AND HUMAN BUILDING INTERACTION

ARSALAN HEYDARIAN1, JOAO P. CARNEIRO2, DAVID GERBER3, BURCIN BECERIK-GERBER4, TIMOTHY HAYES5 and WENDY WOOD6 1,2,3,4 University of Southern California, Los Angeles, United States {heydaria, jcarneir, dgerber, becerik, hayest, wendy.wood}@usc.edu

Abstract. This research prefaces the need for engaging with end-users in early stages of design as means to achieve higher performing de-signs with an increased certainty for end-user satisfaction. While the architecture, engineering, and construction (AEC) community has previously used virtual reality, the primary use has been for coordina-tion and visualization of Building Information Models (BIM). This work builds upon the value of use of virtual environments in AEC processes but asks the research question "how can we better test and measure design alternatives through the integration of immersive vir-tual reality into our digital and physical mock up workflows? " The work is predicated on the need for design exploration through associa-tive parametric design models, as well as, testing and measuring de-sign alternatives with human subjects. The paper focuses on immer-sive virtual environments (IVEs) and presents a literature review of the use of virtual environments for integrating end-user feedback dur-ing the design stage. In a controlled pilot experiment, the authors find that human participants perform similarly in IVE and the physical en-vironment in everyday tasks. The participants indicated they felt a strong sense of "presence" in IVE. In the future, the authors plan on using IVE to explore the integration of multi agent systems to impact building design performance and occupant satisfaction.

Keywords. Virtual Reality; Prototyping; Design Technology; Immer-sive Virtual Environments; Feedback.

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1. Introduction

Making design adjustments earlier in a project’s life cycle reduces the over-all cost of the project (Eastman, 2008). Design adjustments can be better in-formed by involving end-users early during the design phase of a project in order to meet their expectations and deliver high quality products. However, due to lack of time and a growing number of parties involved in design and construction phases, end-user involvement is usually minimized (Oijevaar et al, 2009). Recently, the use of augmented reality (integrating virtual and simulated information with physical environments), virtual reality (comput-er-simulated environment that can simulate a physical presence through cre-ating a visualization of a real or imaginary environment), and immersive vir-tual environments (IVE – allowing user interactivity and immersion within virtual environments to provide a feeling of presence) has increased in dif-ferent domains. In this paper, the authors examine if IVEs can be used as a cost-effective tool to involve end-users during the design phase of a project. In order to examine this, human performance on routine tasks in a physical environment were compared to the performance in an identical IVE (e.g., same room size, objects, lighting). By proving that humans perform similarly in both environments, designers can use end users’ feedback from virtual environments effectively in making decisions about design alternatives for physical environments.

In this paper, the authors explore the use of IVEs for an office space by (1) evaluating the end-users’ sense of presence within an IVE through ques-tionnaires; and (2) comparing human performance on a set of identical tasks in a virtual design alternative and a physical environment with same archi-tectural settings. These alternatives were created through a custom workflow that translates the design intent from an associative parametric BIM tool to an IVE, in which the geometry, lighting, and coupled configurations of these environments were modified. After completing the assigned tasks, partici-pants filled out questionnaires, measuring the realism of the virtual environ-ment, and user experience in performing the assigned tasks, and users’ sense of presence.

2. Background

In the past two decades, the use of virtual reality has increased in various domains, such as in education (Bailenson et al, 2008; Wagner et al, 2013), the military (Psotka, 1995), and various medical fields (Johnsen et al, 2005). The AEC industry, an industry that relies significantly on visual communica-tion, has also made its transition in to adopting the use of virtual reality in the past decade (Kim et al, 2013).

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With the advent of virtual and augmented reality along with the advances in the field of human-computer interaction, AEC professionals have the op-portunity to bring their design alternatives into IVEs for evaluating them in a coupled fashion with end-user feedback (Maldovan et al, 2006). To involve end-users in the design phase, (Dunston et al, 2007) brought healthcare or-ganization end-users (e.g., doctors, nurses, etc.) into an IVE in order to eval-uate the proposed design of a new hospital. Previous research has suggested that IVEs can reduce the amount of time needed to modify designs, provide detailed information about a potential design to the reviewers, and improve the communication between owners, architects, and engineers (Majumdar et al, 2006; Maldovan et al, 2006). These environments can be utilized as a new approach for involving end-users by combining the strengths of pre-construction mock-ups and BIM models (Bardram et al, 2002; Dunston et al, 2007); they can provide the sense of presence found in physical mock-ups and make evaluation of numerous potential design alternatives possible in a timely and cost-efficient manner (Shiratuddin et al, 2004; Chan and Weng, 2005; Eastman, 2008). Additionally, such immersive environments can po-tentially be used as a tool for building designers and engineers to study end-user behaviour and satisfaction within a design alternative.

To confirm if IVEs are adequate for analysing and comparing design al-ternatives, it is important to study users’ performance within such environ-ments and compare it to the real-world settings. Prior research has shown that IVEs can be used effectively to measure performance, such as in exam-ining behavioural compliance to different emergency exit cues (Duarte et al, 2013). Additionally, other research has examined how perception of statues varies within IVE, physical environments, and augmented reality (Huang and Wang, 2008). However, there is a need to further examine how perfor-mance in everyday tasks in IVE compares to physical environments when features of the design alternative are changed (e.g., lighting, geometry).

3. Methodology

The authors of this paper examine whether end-users’ performances on daily office related tasks (e.g., reading, writing, communication, etc.) differ be-tween an immersive virtual office environment and a physical office envi-ronment. To evaluate if an IVE is an adequate representation of a physical environment, specifically two parameters were measured: (1) user perfor-mance when given simple tasks, such as reading a passage; and (2) user per-ception of colour and brightness by identifying coloured objects in the room. These parameters were measured based on the speed and accuracy of the

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performed tasks to determine whether IVE has any negative effects on users’ vision and performance on the given tasks.

3.1. EXPERIMENT AND HYPOTHESIS

An identical 3D virtual model of an office room at the University of South-ern California with the same dimensions and objects (e.g., desk, bookshelf, chairs, etc.) was created (Figure 1). The physical office environment had a window for natural light and four available lighting settings: (1) no light bulbs on, (2) two lights bulbs on, (3) four light bulbs on, and (4) 6 light bulbs on. Previous research has suggested that different lighting conditions and variations in illuminance level and colour may influence interpersonal be-haviour and human performance on tasks that are primarily cognitive in na-ture (Baron et al, 1992). Therefore, lighting settings two and four were se-lected for representing dark and bright conditions of the room, respectively. Two 3D virtual models were created based on these two conditions (i.e., dark and bright). The experiments in the physical environment also used two conditions of the physical room: dark and bright. Participants were asked to perform similar tasks that measured their performance and perception in all four environments.

Figure 1. Photos of the physical environment (left) and virtual models of the physical envi-ronment (right), representing the two conditions

The changes (Δ) in performance for speed and accuracy were then deter-mined ‘within’ each environment (e.g., between the bright and dark condi-tions in the physical environment and between the bright and dark conditions in the virtual environment). The user performance between the two environ-ments was compared by determining if there was any difference ‘between’ the Δ for the physical environment and the Δ for the virtual environment.

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As shown in figure 2, rooms a and a’ are considered for the dark rooms and b and b’ are considered for the bright rooms for the physical environ-ment and virtual environment, respectively. The changes in performance be-tween a – b and a’ – b’ is shown by Δ1 and Δ2. The authors hypothesized that in order for the IVE to be an adequate representation of a physical envi-ronment, Δ1 ≈ Δ2. In order to not reject this hypothesis, a p-value greater than 0.05 is needed as a result of the statistical analysis.

Figure 2. Experiment Setup

3.2. MODEL AND APPARATUS

The base structure of the IVE was designed in Revit© 2013. 3ds Max© was used to modify the model, add materials, and lighting. The model was then exported to the IVE software: Architecture Interactive. The system configu-ration is composed of a Microsoft© Xbox Kinect, an Oculus Head Mounted Display (HMD), a tracker, a Microsoft© Windows graphics workstation with NVIDIA© 3000M graphics card. To increase the sense of presence and to allow participants realistically interact with the IVE, the Kinect was used to track the body displacement (3 Degrees-of-Freedom - DoF), the HMD was used to track the head rotation (3 DoF), and the tracker was used to nav-igate through the room, providing 4 DoF. Figure 3 shows the procedure for creating the models and the apparatus used for this experiment.

Figure 3. Modelling and apparatus

Oculus Goggles

Revit 3D MaxArchitecture Interactive

Modeling Adjustments

Interactivity tool

Alternative Models

3D Model Rendering

Xbox Kinect

Tracker / Controller

3 DoF – Head Rotation

3 DoF – Body Displacement

4 DoF –Rotation +

Displacement

Immersive Virtual Environment

Bright

Dark

Physical World IVE

Δ1 Δ2

=

Performance in Physical Room

Performance in IVE Room

Performance in Physical Room

Performance in IVE Room

a a’

b b’

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3.2. EXPERIMENT PROCEDURE

In order to test our hypothesis, an experiment was conducted with 9 partici-pants. The participants were graduate students of the University of Southern California, between the ages of 21 to 35 years old. An IRB (Institutional Re-view Board) approval was obtained and all participants completed a consent form. None of them reported any prior experience with IVEs. Since partici-pants were later asked to identify objects based on colour, they were simply asked if they had normal or corrected visual acuity through a questionnaire for the purpose of this pilot experiment.

First, the participants were trained how to navigate within an IVE differ-ent from the environment used in the actual experiment using the tracker. They were provided with instructions on how to move from one side of the room to another side using the tracker as the main navigation tool. Other tasks such as crouching, turning head, and grabbing and moving objects in the room were also part of this training. Once the participants felt comforta-ble with the IVE, they were asked to remove the head mounted display and were asked about their general feeling about the environment. This precau-tion was used to ensure the participants were not getting any motion sickness and they have felt comfortable with the virtual environment.

The participants were then randomly assigned to one of the four settings (figure 2) in order to eliminate any order effects. In each environment the participants were given two tasks of (1) reading a passage on a computer screen; and (2) identifying books of a specific colour in 30 seconds. For the first task, they were specifically told to ensure they read the passages thor-oughly as they will be asked comprehension questions about it. The duration to read the passage was recorded. For the second task, at the end of 30 sec-onds, they were asked how many books they found in the bookshelf and/or around the room and this number was recorded. Once the two tasks were completed, they were given four multiple choice questions about the passage and the number of correct responses was recorded. Once each participant completed the first environment he/she was asked to take a five minute break and was taken to the second environment. The same procedure as the first environment took place but they were assigned a different passage and were asked to count a different colour of books; this was done to reduce the learn-ing effect that the participants could have during the experiments. Partici-pants were randomly assigned to the IVE or the physical environment. With-in IVE and the physical environment, they were then randomly assigned to complete the tasks first in the dark environment or bright environment. Once the participants completed their assigned tasks for each of the four set-tings, they were given a questionnaire form to fill out about their experience

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in the IVE. They were asked to describe their sense of presence in the envi-ronment, whether they thought that the virtual office environment was a good representation of the physical office room, and if they thought their performance was affected by the light settings in the room. Figure 4 shows some of the participants using the IVE.

Figure 4. Participants Interacting with IVE

4. Results

The results indicate that the there are no significant differences between the Δs. Three Δs from each environment (physical and virtual) were computed for each of the following parameters between the dark and bright conditions: (1) comprehension, which was the ratio of correctly answered questions to all questions for each passage, (2) speed, which was a ratio based on the par-ticipants’ speed of reading and the number of words (word/seconds), and (3) object detection, which was the ratio of number of found books of a speci-fied colour to the total number of books of a specified colour in the room. The Δs computed for each parameter were then compared between the phys-ical and virtual environment. An independent sample t-test was performed for each of these three parameters and no significant differences were found between the environments for all parameters. Table 1 shows the participants Δs for each of the six settings along with the averages. Table 2 shows the p-values associated with the t-test analysis.

In terms of performance on the assigned tasks, it appears that participants performed similarly in the IVE and physical environment. However, partici-pants did appear to have some navigation related trouble in the IVE. This could be improved with more training and practice in the future studies.

Reading Task

Object Detection

Apparatus Set-up

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Table 1- Physical and virtual environment parameters Δ for each participant

Physical Environment Immersive Virtual Environment

Comprehen-sion

(Δ Ratio of Correct ans.)

Reading speed

(Δ word/sec)

Object De-tection

(Δ Ratio of correct ans.)

Comprehen-sion

(Δ Ratio of Correct ans.)

Reading speed

(Δ word/sec)

Object Detection (Δ Ratio of correct

ans.) P1 0.250 0.011 -0.129 -0.250 -0.014 0.080 P2 -0.250 0.001 0.018 -0.250 -0.113 0.030 P3 0.000 0.314 0.043 0.250 -0.307 -0.037 P4 0.000 0.203 0.008 -0.250 0.046 -0.005 P5 -0.250 -0.203 0.058 0.000 -0.008 0.008 P6 0.000 0.167 -0.059 -0.250 -0.082 0.091 P7 0.250 -0.110 0.418 0.250 0.131 -0.080 P8 0.250 -0.220 0.075 -0.250 0.175 0.000 P9 0.250 -0.342 -0.007 0.000 -0.253 0.000

Avg 0.056 -0.020 0.047 -0.083 -0.047 0.010

Table 2- t-test Results for each Δ

Δ Comprehension

(Real vs. VR)

Δ Reading Speed

(Real vs. VR)

Δ Object-Detection

(Real vs. VR)

t-test(p-value) 0.185 0.765 0.500

The object identification test was a measure of participant’s colour per-

ception in both environments. The lack of difference in the Δs between the IVE and physical environment in the object detection task suggests that par-ticipants had similar colour perceptions in both of these environments.

The participants indicated that the IVE appeared very realistic, in terms of the setup of the room, as well as, their depth perception when compared to the physical environment. They stated that the tasks were comparable in dif-ficulty in the IVE compared to the physical environment. Additionally, the participants indicated that they felt that they were physically inside of the of-fice room in the IVE. These responses to the exit questionnaire suggest that participants felt a sense of "presence" in the IVE similar to the presence in the physical environment.

5. Limitation and Future Work

Although serving as a first step toward the research goals, this study had lim-itations. There was a small sample size of 9 participants which will be in-creased for the full experiment through a proper power analysis. There were a few features of the model (e.g., outside window view, additional objects in the room, etc.) that need to be improved to better represent the physical room in the IVE. The authors measured participants’ presence through preliminary

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set of questionnaires, but for the full experiment the authors will use more established instruments and questionnaires such as those suggested by (Witmer and Singer, 1998). As part of the future work, the authors will look in to effects of lighting and geometrical changes in an IVE on human per-formance and energy-use behaviour. The authors will also use IVEs to ex-plore the integration of multi agent systems to impact building design per-formance and occupant satisfaction.

6. Conclusion

End-user feedback during the design phase is vital in enhancing satisfaction and increasing quality of the end product. The authors aimed to explore if IVEs can be an efficient way to involve end-users. This paper demonstrated that there were no differences in human performance on everyday office-related tasks in a physical environment and in an IVE. Additionally, follow-up questionnaires revealed that participants thought that the virtual environ-ment was a satisfactory representation of the physical environment and that they felt a sense of "presence" within the IVE. With performance being sim-ilar in these environments, virtual environments can be used as a way to ex-plore design alternatives and various design changes, such as lighting and geometry changes in a room, and their impact on human perception and be-haviour. More comprehensive tests with larger sample sizes are among the authors’ future directions.

Acknowledgement

This project is part of the National Science Foundation funding under the contract 1231001. Any discussion, procedure, results, and conclusion discussed in this paper are the authors’ views and do not reflect the views of National Science Foundation. Special thanks to all of the participants and to the researchers that contributed to this project; specifically to Saba Khashe for her contributions in preparing and running the experiment.

References

BAILENSON, J. N., YEE, N., BLASCOVICH, J., BEALL, A. C., LUNDBLAD, N. & JIN, M. 2008. The Use of Immersive Virtual Reality in the Learning Sciences: Digital Transformations of Teachers, Students, and Social Context. Journal of the Learning Sciences, 17, 102-141.

BARDRAM, J., BOSSEN, C., LYKKE-OLESEN, A., NIELSEN, R. & MADSEN, K. H. 2002. Virtual video prototyping of pervasive healthcare systems. Proceedings of the 4th conference on Designing interactive systems: processes, practices, methods, and techniques. London, England: ACM.

BARON, R., REA, M. & DANIELS, S. 1992. Effects of indoor lighting (illuminance and spectral distribution) on the performance of cognitive tasks and interpersonal behaviors: The potential mediating role of positive affect. Motivation and Emotion, 16, 1-33.

CHAN, C.-S. & WENG, C.-H. 2005. How Real is the Sense of Presence in a Virtual Environment? Applying Protocol Analysis for Data Collection. Digital Opportunities: Proceedings of the 10th International Conference on Computer-Aided Architectural Design Research in Asia. New Delhi: Architexturez Imprints.

Page 10: immersive virtual environments: experiments on impacting design ...

738 A. HEYDARIAN ET AL

DUARTE, E., REBELO, F., TELES, J. & WOGALTER, M. S. 2013. Behavioral compliance for dynamic versus static signs in an immersive virtual environment. Applied ergonomics.

DUNSTON, P., ARNS, L., and MCGLOTHLIN, J.A. 2007. An Immersive Virtual Reality Mock-Up for Design Review of Hospital Patient Rooms. 7th Int. Conf. on Consturction Applications of Virtual Reality. University Park, PA, USA.

EASTMAN, C. M. 2008. BIM Handbook: A Guide to Building Information Modeling for Owners, Managers, Designers, Engineers and Contractors, Wiley.

HUANG, Y. & WANG, P. 2008. The Comparisons of Interactive Demos and Cognitive Behaviors in the Virtual Environments for Representing 3D Artifacts. Architecture 'in computro' - Integrating Methods and Techniques: 26th eCAADe Conference Proceedings. Antwerpen, Belgium:

JOHNSEN, K., DICKERSON, R., RAIJ, A., LOK, B., JACKSON, J., MIN, S., HERNANDEZ, J., STEVENS, A. & LIND, D. S. Experiences in using immersive virtual characters to educate medical communication skills. Virtual Reality, 2005. Proceedings. VR 2005. IEEE, 12-16 March 2005 2005. 179-186.

KIM, M. J., WANG, X., LOVE, P. E., LI, H. & KANG, S.-C. 2013. Virtual reality for the built environment: a critical review of recent advances. ITcon, 18, 279-305.

MAJUMDAR, T., FISCHER, M. A. & SCHWEGLER, B. R. Conceptual design review with a virtual reality mock-up model. Joint International Conference on Computing and Decision Making in Civil and Building Engineering, 2006.

MALDOVAN, K. D., MESSNER, J. I. & FADDOUL, M. 2006. Framework for Reviewing Mockups in an Immersive Environment. CONVR 2006: 6th International Conference on Construction Applications of Virtual Reality.

OIJEVAAR, K., JOVANOVIC, M. & DEN OTTER, A. 2009. User Involvement in the Design Process of Multifunctional Buildings Proceedings of the Changing Roles: New Roles and New Challenges (CR'09), 485-495.

PSOTKA, J. 1995. Immersive training systems: Virtual reality and education and training. Instructional Science, 23, 405-431.

SHIRATUDDIN, M. F., THABET, W. & BOWMAN, D. 2004. Evaluating the effectiveness of virtual environment displays for reviewing construction 3D models. CONVR 2004, 87-98.

WAGNER, R., PIOVESAN, S. D., PASSERINO, P. D. L. M. & DE LIMA, J. V. Using 3D virtual learning environments in new perspective of education. Information Technology Based Higher Education and Training (ITHET), 2013 International Conference on, 10-12 Oct. 2013 2013. 1-6.

WITMER, B. G. & SINGER, M. J. 1998. Measuring presence in virtual environments: A presence questionnaire. Presence: Teleoperators and virtual environments, 7.