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Research on Fidelity metrics for 3D immersive based on spatial perception and cognition


This line of research is exploring fidelity metrics for complex immersive simulations based on spatial perception (slant perception) and spatial cognition (memory awareness performance). An innovative motoric measure of slant based on gait is proposed as, in effect, the angle between the foot and the walking surface during walking, exploring behavioural fidelity of simulations. This work investigates whether the proposed ecologically valid, action-based measure is affected by factors such as material of the walking surface and inclination of the walking ramps. Experimental studies were conducted in a real environment set-up and in its virtual counterpart. In the real environment, the measure slightly overestimated the inclined path whereas in the virtual environment it slightly underestimated the inclined path. The results imply that the proposed slant measure is modulated by motoric caution. Since the "reality" of the synthetic environment was relatively high, results should have revealed the same degree of caution as in the real world, however, that is not the case, mainly attributed to the appearance of reflective properties of materials. It seems reasonable to assume that a larger foot angle arises from a longer stride, and thus a faster gait, implying that the walker is less cautious. On this interpretation of the results, people become more cautious when the ground plane is steep, slippery, or virtual. Still investigating fidelity metrics, we conduct research on the effect of varied rendering algorithms on spatial awareness in 3D immersive simulations. An individual’s prior experience will influence how new visual information in a scene is perceived and remembered. Classic memory research suggests that accuracy of memory performance per se is an imperfect reflection of the cognitive activity (awareness states) that underlies performance in memory tasks. The aim of this research is to investigate the effect of varied visual fidelity on transfer of training in the real-world after exposure to immersive simulations representing the real-world scene. A between groups experiment was carried out to explore the effect of rendering quality on location-based recognition memory for objects and associated states of awareness followed by a retention study a week after the initial test. The experimental space, consisting of one room was rendered either flat-shaded or using radiosity rendering. The computer graphics simulation was displayed on a stereo head-tracked Head Mounted Display. Participants completed a recognition memory task in the real-world scene by physically arranging objects (in their physical form) in the real world room after exposure to its simulation counterpart and reported one of four states of awareness following object recognition. These reflected the level of visual mental imagery involved during retrieval, the familiarity of the recollection and also included guesses. The scene incorporated objects that ‘fitted’ into the specific context of an academic’s office referred to as consistent objects and objects which were not related to the schema in place referred to as inconsistent objects. Interestingly, results revealed a higher proportion of recollections associated with mental imagery when trained in the flat-shaded condition, supporting similar results from previous studies that did not involve investigations of transfer of training. Memory psychology indicates that visually-induced recollections require stronger attentional processing in the first instance than those based on familiarity. A tentative claim would therefore be that those immersive environments that are distinctive because of their variation from ‘real’ recruit stronger attentional resources. This additional attentional processing may therefore bring about a change in participants’ subjective experiences of ‘remembering’ when they later recall the environment.

Research Topics

Presence in Virtual Environments


Facial animation, Synthetic Emotional characters, Eye tracking and Neurocorrelates of Empathy


Spatial Cognition and Spatial Awareness in 3D Simulations


Distributed and Embodied Virtual Environments


R&D Projects


Related Persons

Nikos Zervoudakis Mr. zervoudakis at