In recent work [4,2], we have discovered that people are able to make surprisingly accurate judgments about egocentric distances in an immersive virtual environment (IVE) in the special case that the IVE represents a ...
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ISBN:
(纸本)1595934294
In recent work [4,2], we have discovered that people are able to make surprisingly accurate judgments about egocentric distances in an immersive virtual environment (IVE) in the special case that the IVE represents a high fidelity model of the same physical space that the user is actually occupying, and the user has been able to unambiguously verify this by viewing the real space prior to donning the display upon which the corresponding virtual environment is presented. Through followup experiments in multiple locales, we have verified that the key factor enabling this distance perception accuracy is fact of co-location, rather than any particular characteristics of the physical environment [1]. One possible interpretation of these intriguing results is that observers are better enabled to make accurate judgments of egocentric distance in an IVE when they are when they are cognitively 'immersed' or 'present' in the IVE - i.e. when they readily accept the virtual environment as being 'equivalent' to the real world and are therefore prepared to act in the virtual world in the same way that they act in the real world [3]. However, another interpretation is also possible: it could be that people are able to make accurate judgments of egocentric distances in a virtual environment when they know that it exactly corresponds to a recently viewed real environment because they are able to form a metrically accurate mental model of the spatial structure of the real environment from their brief exposure to it, so that when they are subsequently presented with the virtual environment they simply calibrate their mental model of distances in the IVE to be consistent with their remembered model of the corresponding real environment. In order to disambiguate between the 'presence' hypothesis and the 'spatial memory' hypothesis, we conducted the following study. Using a between-subjects design, we asked observers to make judgments of egocentric distance via blind walking in a real ro
Although a wide range of virtual reality (VR) systems are in use, there are few guidelines to help system and application developers select the components most appropriate for the domain problem they are investigating...
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ISBN:
(纸本)1595934294
Although a wide range of virtual reality (VR) systems are in use, there are few guidelines to help system and application developers select the components most appropriate for the domain problem they are investigating. Using the results of an empirical study, we developed such guidelines for the choice of display environment for four specific, but common, volume visualization problems: identification and judgment of the size, shape, density, and connectivity of objects present in a volume. These tasks are derived from questions being asked by collaborators studying Cystic Fibrosis (CF). We compared user performance in three different stereo VR systems: (1) head-mounted display (HMD);(2) fish tank VR (fish tank);and (3) fish tank VR augmented with a haptic device (haptic). HMD participants were placed "inside" the volume and walked within it to explore its structure. Fish tank and haptic participants saw the entire volume on-screen and rotated it to view it from different perspectives. Response time and accuracy were used to measure performance. Results showed that the fish tank and haptic groups were significantly more accurate at judging the shape, density, and connectivity of objects and completed the tasks significantly faster than the HMD group. Although the fish tank group was itself significantly faster than the haptic group, there were no statistical differences in accuracy between the two. Participants classified the HMD system as an "inside-out" display (looking outwards from inside the volume), and the fish tank and haptic systems as "outside-in" displays (looking inwards from outside the volume). Including haptics added an inside-out capability to the fish tank system through the use of touch. We recommend an outside-in system because it offers both overview and context, two visual properties that are important for the volume visualization tasks we studied. In addition, based on the haptic group's opinion (80% positive) that haptic feedback aided comprehe
The proceedings contain 45 papers from the 1st symposium on applied perception in graphics and visualization, apgv 2004. The topics discussed include: recalibration of rotational locomotion in immersive virtual enviro...
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ISBN:
(纸本)1581139144
The proceedings contain 45 papers from the 1st symposium on applied perception in graphics and visualization, apgv 2004. The topics discussed include: recalibration of rotational locomotion in immersive virtual environments;distance perception in real and virtual environments;vision realistic rendering: simulation of the scanned foveal image from wavefront data on human subjects;enhancing perceived depth in images via artistic matting;selective rendering of task related scenes;effective color coding of menu design for movie genres;observations of visual and audio coaching methods in a virtual laparoscopic training environment;selective rendering of task related sceness and causes of depth perception errors.
In the context of medical volume visualization, it is useful to study how effectively the visualization depicts anatomical structures and how well features of anatomical structures can be discerned in order to make de...
ISBN:
(纸本)1595931392
In the context of medical volume visualization, it is useful to study how effectively the visualization depicts anatomical structures and how well features of anatomical structures can be discerned in order to make decisions. So it is important to know what factors affect the understanding of rendered images and further to design more effective rendering algorithms under considering these factors. However, they are not fully evaluated. These are important for users to get better understanding of a 3D data set, and to help to develop effective visualization methods. Because visualization renditions are perceived through human visual perception, visual perception has important effects on mental models. This paper aims to analyze the roles of perception for volume visualization and use the perceptual analysis results to design volume visualization methods.
In compositing applications, objects depicted in images frequently have to be separated from their background, so that they can be placed in a new environment. Alpha mattes are important tools aiding the selection of ...
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In this paper we describe an experiment to obtain information about the perceptual potential of the human visual system regarding shadow perception. Shadows play an important part for communicating spatial structures ...
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In this paper, we take a new look at the problem of texturing surfaces so that they can be displayed layered over each other but remain clearly visible. Finding optimal textures that solve this problem is complex beca...
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