Pankaj Khanna

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Does greater visual realism induce greater participant presence in immersive virtual environments (VE)? Presence refers to how realistically participants respond to the environment as well as their subjective sense of being in the place depicted by the VE. Thirty-three people were exposed for three minutes to a virtual environment depicting a precipice(More)
A 30-d course of oral administration of a semipurified extract of the root of Withania somnifera consisting predominantly of withanolides and withanosides reversed behavioral deficits, plaque pathology, accumulation of β-amyloid peptides (Aβ) and oligomers in the brains of middle-aged and old APP/PS1 Alzheimer's disease transgenic mice. It was similarly(More)
This paper describes an experiment that examines the influence of visual realism on reported presence. 33 participants experienced two different renderings of a virtual environment that depicts a pit in the centre of a room, in a head-tracked head-mounted display. The environment was rendered using parallel ray tracing at 15fps,mbut in one condition ray(More)
This paper describes an algorithm that provides real-time walkthrough for globally illuminated scenes comprising of ideal diffuse and specular polygonal surfaces. A type of light field data structure is used for propagating radiance outward from light emitters through the scene and accounts for all L(S|D)* light paths. The light field employed is(More)
This paper describes an algorithm that provides real-time walkthrough for globally illuminated scenes that contain mixtures of ideal diffuse and specular surfaces. A type of light field data structure is used for propagating radiance outward from light emitters through the scene, accounting for any kind of L(S\D)* light path. The light field employed is(More)
Does realistic lighting in an immersive VR application enhance presence - that is, the participants' feeling that they're actually in the scene and behaving accordingly? Part 1 of this study indicated that presence is more likely with real-time ray tracing than with ray casting. However, that research couldn't separate the effects of overall illumination(More)
PURPOSE/AIM Results of treatment of chronic hepatitis C (CHC) with pegylated interferon plus ribavirin (PEG-RBV) are mainly available from well-designed clinical trials, and only few 'real-life' studies which give a true picture of success of therapy are available. Such data in Indian patients is scarce. This prospective study aimed to evaluate the(More)
Real-time global illumination in VR systems enhances scene realism by incorporating soft shadows, reflections of objects in the scene, and color bleeding. The virtual light field (VLF) method enables real-time global illumination rendering in VR. The VLF has been integrated with the extreme VR system for real-time GPU-based rendering in a cave automatic(More)
Ray tracing dynamically changing scenes with unstructured motion has long been a problem for raytraversal acceleration schemes. When polygons are transformed arbitrarily, the cost of updating traditional spatial data-structures can be quite high [TL03][IW03]. We propose a ray traversal scheme that is well suited to scenes with dynamically changing objects(More)