Visual direction as a metric of virtual space

Two experiments examine the abilities of ten subjects to visualize directions shown on a perspective display. Subjects indicated their perceived directions by adjusting a head-mounted cursor to correspond to the direction depicted on the display. This task is required of telerobotic operators who use map-like pictures of their workspace to determine the direction of objects seen by direct view. Results show significant open loop judgment biases that may be composed of errors arising from misinterpretation of the map geometry and overestimation of gaze direction

Volumetric visualization of 3D data

In recent years, there has been a rapid growth in the ability to obtain detailed data on large complex structures in three dimensions. This development occurred first in the medical field, with CAT (computer aided tomography) scans and now magnetic resonance imaging, and in seismological exploration. With the advances in supercomputing and computational fluid dynamics, and in experimental techniques in fluid dynamics, there is now the ability to produce similar large data fields representing 3D structures and phenomena in these disciplines. These developments have produced a situation in which currently there is access to data which is too complex to be understood using the tools available for data reduction and presentation. Researchers in these areas are becoming limited by their ability to visualize and comprehend the 3D systems they are measuring and simulating

How sketches work: a cognitive theory for improved system design

Evidence is presented that in the early stages of design or composition the mental processes used by artists for visual invention require a different type of support from those used for visualising a nearly complete object. Most research into machine visualisation has as its goal the production of realistic images which simulate the light pattern presented to the retina by real objects. In contrast sketch attributes preserve the results of cognitive processing which can be used interactively to amplify visual thought. The traditional attributes of sketches include many types of indeterminacy which may reflect the artist's need to be "vague". Drawing on contemporary theories of visual cognition and neuroscience this study discusses in detail the evidence for the following functions which are better served by rough sketches than by the very realistic imagery favoured in machine visualising systems. 1. Sketches are intermediate representational types which facilitate the mental translation between descriptive and depictive modes of representing visual thought. 2. Sketch attributes exploit automatic processes of perceptual retrieval and object recognition to improve the availability of tacit knowledge for visual invention. 3. Sketches are percept-image hybrids. The incomplete physical attributes of sketches elicit and stabilise a stream of super-imposed mental images which amplify inventive thought. 4. By segregating and isolating meaningful components of visual experience, sketches may assist the user to attend selectively to a limited part of a visual task, freeing otherwise over-loaded cognitive resources for visual thought. 5. Sequences of sketches and sketching acts support the short term episodic memory for cognitive actions. This assists creativity, providing voluntary control over highly practised mental processes which can otherwise become stereotyped. An attempt is made to unite the five hypothetical functions. Drawing on the Baddeley and Hitch model of working memory, it is speculated that the five functions may be related to a limited capacity monitoring mechanism which makes tacit visual knowledge explicitly available for conscious control and manipulation. It is suggested that the resources available to the human brain for imagining nonexistent objects are a cultural adaptation of visual mechanisms which evolved in early hominids for responding to confusing or incomplete stimuli from immediately present objects and events. Sketches are cultural inventions which artificially mimic aspects of such stimuli in order to capture these shared resources for the different purpose of imagining objects which do not yet exist. Finally the implications of the theory for the design of improved machine systems is discussed. The untidy attributes of traditional sketches are revealed to include cultural inventions which serve subtle cognitive functions. However traditional media have many short-comings which it should be possible to correct with new technology. Existing machine systems for sketching tend to imitate nonselectively the media bound properties of sketches without regard to the functions they serve. This may prove to be a mistake. It is concluded that new system designs are needed in which meaningfully structured data and specialised imagery amplify without interference or replacement the impressive but limited creative resources of the visual brain

Anatomy: The Relationship Between Internal and External Visualizations

This dissertation explored the relationship between internal and external visualizations and the implications of this relationship for comprehending visuospatial anatomical information. External visualizations comprised different computer representations of anatomical structures, including: static, animated, non-interactive, interactive, non-stereoscopic, and stereoscopic visualizations. Internal visualizations involved examining participants’ ability to apprehend, encode, and manipulate mental representations (i.e., spatial visualization ability or Vz). Comprehension was measured with a novel spatial anatomy task that involved mental manipulation of anatomical structures in three-dimensions and two-dimensional cross-sections. It was hypothesized that performance on the spatial anatomy task would involve a trade-off between internal and external visualizations available to the learner. Results from experiments 1, 2, and 3 demonstrated that in the absence of computer visualizations, spatial visualization ability (Vz) was the main contributor to variation in spatial anatomy task performance. Subjects with high Vz scored higher, spent less time, and were more accurate than those with low Vz. In the presence of external computer visualizations, variation in task performance was attributed to both Vz and visuospatial characteristics of the computer visualization. While static representations improved performance of high- and low-Vz subjects equally, animations particularly benefited high Vz subjects, as their mean score on the SAT was significantly higher than the mean score of low Vz subjects. The addition of interactivity and stereopsis to the displays offered no additional advantages over non-interactive and non-stereoscopic visualizations. Interactive, non-interactive, stereoscopic and non-stereoscopic visualizations improved the performance of high- and low-Vz subjects equally. It was concluded that comprehension of visuospatial anatomical information involved a trade-off between the perception of external visualizations and the ability to maintain and manipulate internal visualizations. There is an inherent belief that increasing the educational effectiveness of computer visualizations is a mere question of making them dynamic, interactive, and/or realistic. However, experiments 1, 2, and 3 clearly demonstrate that this is not the case, and that the benefits of computer visualizations vary according to learner characteristics, particularly spatial visualization ability

Towards 3-D Sound: Spatial Presence and the Space Vacuum

This chapter demonstrates the evolution of relationships between sound design and music in cinematic representations of the interstellar space vacuum. Mera provides a framework for understanding how audiences believe they are physically present in the represented environment and argues that, in the late 2000s, we move towards three-dimensional (3-D) sound, an aesthetic and technical extension of the superfield and the ultrafield as defined by Chion and Kerins, respectively. 3-D Sound’s primary characteristic is the emancipation of music from a fixed sound-stage spatialization, resulting in greater fluidity between sound design and music. This chapter examines the relationship between two types of spatial presence, articulating both the audience’s suspension of disbelief within a film’s narrative world and the spatial presence of sound and music within a multichannel cinema environme

The effects of progressive levels of 3d authenticity antecedents and consequences on consumers’ virtual experience

This study investigates the effects of authentic three dimensional (3D) product visualisation antecedents on 3D authenticity, and the effects of 3D authenticity consequences on consumers’ virtual experience. A hypothetical retailer Web site presents a variety of laptops for the within-subjects laboratory experiments. In a first experiment, a one-way ANOVA compares telepresence and authenticity scores. The second experiment uses two-way repeated measures ANOVA to determine the effects of the progressive levels of the antecedents on 3D authenticity. In a third experiment, two-way repeated measures ANOVA determine the effects of the progressive levels of 3D authenticity consequences on willingness to purchase. The results show that authenticity is more useful than telepresence in simulating consumers’ virtual experience. The high levels of control and animated colours lead to higher authenticity for the site. In addition, the high levels of 3D utilitarian and hedonic constructs enhance willingness to purchase from the online retailer

Instruction with 3D Computer Generated Anatomy

Research objectives. 1) To create an original and useful software application; 2) to investigate the utility of dyna-linking for teaching upper limb anatomy. Dyna-linking is an arrangement whereby interaction with one representation automatically drives the behaviour of another representation. Method. An iterative user-centred software development methodology was used to build, test and refine successive prototypes of an upper limb software tutorial. A randomised trial then tested the null hypothesis: There will be no significant difference in learning outcomes between participants using dyna-linked 2D and 3D representations of the upper limb and those using non dyna-linked representations. Data was analysed in SPSS using factorial analysis of variance (ANOVA). Results and analysis. The study failed to reject the null hypothesis as there was no signi cant di fference between experimental conditions. Post-hoc analysis revealed that participants with low prior knowledge performed significantly better (p = 0.036) without dyna-linking (mean gain = 7.45) than with dyna-linking (mean gain = 4.58). Participants with high prior knowledge performed equally well with or without dyna-linking. These findings reveal an aptitude by treatment interaction (ATI) whereby the effectiveness of dyna-linking varies according to learner ability. On average, participants using the non dyna-linked system spent 3 minutes and 4 seconds longer studying the tutorial. Participants using the non dyna-linked system clicked 30% more on the representations. Dyna-linking had a high perceived value in questionnaire surveys (n=48) and a focus group (n=7). Conclusion. Dyna-linking has a high perceived value but may actually over-automate learning by prematurely giving novice learners a fully worked solution. Further research is required to confirm if this finding is repeated in other domains, with different learners and more sophisticated implementations of dyna-linking

Grasping the Void: Immersion Tactics Using Gesture Controlled Physics Interaction Systems in Virtual Reality

This thesis uses the HTC Vive in Unity to compare two different types of object interaction systems in order to determine the effectiveness of physics based interaction systems in a virtual environment. The research problem that motivates this project is the fact that there is no standardized method for defining successful object interaction techniques in VR. There are numerous interaction techniques in VR that fall short of simulating realistic object interaction. This project explores a physics based interaction system and examines how effective it is by comparing it to a non-physics based system. A model house with various interactable objects is created to compare the two interaction systems. The first system, the naive interaction system, parents an object to the controller model, allowing the user to pick up and throw things in a very simple fashion. This system is compared to a physics based Newtonian system that takes into account mass and velocity during object interactions. The Newtonian system promotes a much deeper sense of immersion for a user due to how accurately the system simulates real life physical interactions. It is clear that creating a high level of mental and physical presence is crucial for a VR experience. Object interaction systems are an integral component of a VR experience that directly contribute to the realism and levels of virtual presence that a user achieves within a virtual environment. The results of this project conclude that physics based interaction systems provide levels of realism and immersion that the naive systems currently cannot achieve The results of this project are beneficial because they demonstrate the positive impact physics based interaction systems have on a VR experience and the need for improved physics systems for the future of VR development