An understanding of the capabilities and advantages of stereo and large displays will help in the survey part of this research. It will provide an understanding of the benefits of having large and stereo displays and the settings can be applied in all the VR projects. A large display is essential to project 3D models on an approximately 1:1 scale, so that they look more realistic. It is expected also to improve task performance. Stereoscopic display will add depth to the flat displays. This will give a sense of distance between objects in the scene and is expected to increase realism as well. Both are critical in making the final visualisation as real as navigating in the real world.
For viewing VR in stereoscopic mode, research has been done to determine the different responses between two groups of human subjects to visual factors of illumination
direction, light source numbers and view point position (Lo and Chalmers 2003). Human judgement of the visual realism of computer-generated images is investigated. Subjects are to decide whether the visual stimulus given to them is real and how much time they take to respond. One group views in stereo while the other does not.
The results showed that subjects involved in stereo-viewing took more time to respond than those who were not. This holds true for responses in all three experiments examining
different illumination directions, the light source numbers from one to five as well as view point variances at 15, 30, 45, 60, 75 and 90 degrees. At least 20 seconds was required to decide the realism of a scene when in stereo. This means that people will not be able to determine much detail when viewing dynamic scenes in stereo. Therefore, more processing power can be saved from using more realistic qualities in the VR scenes like not using shadows and still maintaining the same perceptual response. The paper is crucial in understanding that human beings will require more time to adjust to stereo vision. Therefore, in the proposed survey, participants should be allowed more time to view each simulation choice before moving to another.
The impact of large displays is always important in VR to understand how it affects tasks and users’ characteristics. Some tasks studied include objects manipulation and
navigation in the environment and visual attention abilities of users (Tyndiuk et. al., 2004). Forty subjects go through the experiment viewing in a large wall display with video projection system (3.3m X 2.8m) and a desktop monitor (0.23m X 0.30m). They are asked to sit at 5.5m in front of the large display as well as 0.5m in front of the desktop monitor.
The results showed that performances of users were better whatever the tasks involved in the large display. In the large display, the interaction showed performances gain for the slower subjects while it remained the same for faster subjects. For visual attention abilities test, the performances improved for some users when viewing with large
displays. This paper’s results are crucial in justifying the use of big displays for VR visualisation as it will be able to present architectural designs in the best possible way.
A similar research looking into increased display size and resolution in task performance improvement in virtual environments was done (Bowman and Chen 2006). The interest was in how users work with various displays when using a wayfind aid to help spatial information acquisition and mental map construction. Thirty-two subjects from
intermediate to experienced video gaming backgrounds participated in the experiment.
The experiment used two levels of resolution, at 1280 X 720 and 2560 X 1440 pixels in two display sizes of 48.0” X 27” and 18.8” X 10.6”. The distance of viewing is 24”, so for the large display, a 90 degrees horizontal field-of-view can be achieved while 42.8 degrees can be achieved for the small display.
The results showed that increased display size and resolution improved subjects’
performance for all the varieties of navigation, search and comparison tasks. Large displays do help in facilitating both spatial navigation and information gathering. In the comparison of resolution test, even a large rear-projected screen outperformed a regular- sized monitor with a higher resolution. Therefore, size matters more than resolution if one must choose between the two. Wayfinding aid, even in the small display, did help improve navigation performance significantly. Users did move their heads to cover the big displays, leaning forward in some cases. Users felt more present when experiencing large displays, especially when they were seated close to the screen. The results
reinforced the findings of the previous paper to choose large displays for VR
visualisation but high resolution is optional if economic reasons do not permit it. It also shows that the distance of the audience to the screen should be sufficiently short.
Knowing the pros and cons of stereoscopic visualisation and big displays from the literature review in this category will help greatly in preparing VR projects as well as obtaining the correct settings to show the audience. It is crucial to know the impact of display resolutions and how different displays affect tasks.