Jan Ondrej

Jan Ondrej
Volograms

Doctor of Philosophy

About

43
Publications
21,522
Reads
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883
Citations
Additional affiliations
September 2016 - May 2018
Trinity College Dublin
Position
  • Senior Researcher

Publications

Publications (43)
Preprint
Full-text available
Volumetric video is a new form of visual media that enables novel ways of immersive visualisation and interaction. Currently volumetric video technologies receive a lot of attention in research and standardization, leading to an increasing need for related test data. This paper describes the Volograms & V-SENSE Volumetric Video Dataset which is mad...
Article
Full-text available
Spatial cognition is known to decline with aging. However, little is known about whether training can reduce or eliminate age-related deficits in spatial memory. We investigated whether a custom-designed video game involving spatial navigation, obstacle avoidance, and balance control would improve spatial memory in older adults. Specifically, 56 he...
Conference Paper
Crowd simulation is the act of simulating and controlling the dynamic movement of large groups of virtual characters. Crowd simulation is traditionally a complex and time-consuming process, requiring extensive manual effort to achieve. On the one hand, commercial and liberally licensed tools tend to have many aspects of simulation tightly integrate...
Preprint
Full-text available
Crowd simulation is the act of simulating and controlling the dynamic movement of large groups of virtual characters. Crowd simulation is traditionally a complex and time-consuming process, requiring extensive manual effort to achieve. On the one hand, commercial and liberally licensed tools tend to have many aspects of simulation tightly integrate...
Article
Full-text available
We present 2DToonShade: a semi-automatic method for creating shades and self-shadows in cel animation. Besides producing attractive images, shades and shadows provide important visual cues about depth, shapes, movement and lighting of the scene. In conventional cel animation, shades and shadows are drawn by hand. As opposed to previous approaches,...
Article
Full-text available
We present 2DToonShade: a semi-automatic method for creating shades and self-shadows in cel animation. Besides producing attractive images, shades and shadows provide important visual cues about depth, shapes, movement and lighting of the scene. In conventional cel animation, shades and shadows are drawn by hand. As opposed to previous approaches,...
Conference Paper
Full-text available
Creative studios tend to produce an overwhelming amount of content everyday and being able to manage these data and reuse it in new productions represent a way for reducing costs and increasing productivity and profit. This work is part of a project aiming to develop reusable assets in creative productions. This paper describes our first attempt us...
Conference Paper
This demo paper describes a project that engages cutting-edge free viewpoint video (FVV) techniques for developing content for an augmented reality prototype. The article traces the evolutionary process from concept, through narrative development, to completed AR prototypes for the HoloLens and handheld mobile devices. It concludes with some reflec...
Poster
Full-text available
Natural interaction with virtual objects in AR/VR environments makes for a smooth user experience. Gestures are a natural extension from real world to augmented space to achieve these interactions. Finding discriminating spatio-temporal features relevant to gestures and hands in ego-view is the primary challenge for recognising ego centric gestures...
Conference Paper
Full-text available
We present a semi-automatic method for creating shades and self-shadows in cel animation. Besides producing attractive images, shades and shadows provide important visual cues about depth, shapes, movement and lighting of the scene. In conventional cel animation, shades and shadows are drawn by hand. As opposed to previous approaches, this method d...
Conference Paper
This poster describes a reinterpretation of Samuel Beckett's theatrical text Play for virtual reality (VR). It is an aesthetic reflection on practice that follows up an a technical project description submitted to ISMAR 2017 [O'Dwyer et al. 2017]. Actors are captured in a green screen environment using free-viewpoint video (FVV) techniques, and the...
Preprint
Full-text available
Natural interaction with virtual objects in AR/VR environments makes for a smooth user experience. Gestures are a natural extension from real world to augmented space to achieve these interactions. Finding discriminating spatio-temporal features relevant to gestures and hands in ego-view is the primary challenge for recognising egocentric gestures....
Article
Full-text available
Previous studies have reported an age-related decline in spatial abilities. However, little is known about whether the presence of other, task-irrelevant stimuli during learning further affects spatial cognition in older adults. Here we embedded virtual environments with moving crowds of virtual human pedestrians (Experiment 1) or objects (Experime...
Article
We present a scalable pipeline for Free-Viewpoint Video (FVV) content creation, considering also visualisation in Augmented Reality (AR) and Virtual Reality (VR). We support a range of scenarios where there may be a limited number of handheld consumer cameras, but also demonstrate how our method can be applied in professional multi-camera setups. O...
Article
Full-text available
Affect, space, and multisensory integration are processes that are closely linked. However, it is unclear whether the spatial location of emotional stimuli interacts with multisensory presentation to influence the emotional experience they induce in the perceiver. In this study, we used the unique advantages of virtual reality techniques to present...
Article
Full-text available
We propose a new semantic-level crowd evaluation metric in this paper. Crowd simulation has been an active and important area for several decades. However, only recently has there been an increased focus on evaluating the fidelity of the results with respect to real-world situations. The focus to date has been on analyzing the properties of low-lev...
Conference Paper
Full-text available
Representative distribution of body shapes is needed when simulating crowds in real-world situations, e.g., for city or event planning. Visual realism and plausibility are often also required for visualization purposes, while these are the top criteria for crowds in entertainment applications such as games and movie production. Therefore, achieving...
Conference Paper
We present an algorithmic framework for the early classification of human intentions, and use it to accurately predict future human motions when planning the path of a robot in an environment that is shared with humans. During an off-line learning phase, a classifier that can recognize when a human intends to interact with the robot is trained. At...
Article
Judging the size of a group of people is an everyday task, on which many decisions are based. In the present study, we investigated whether judgment of size of different groups of people depended on whether they were presented through the auditory channel, through the visual channel, or through both auditory and visual channels. Groups of humanoids...
Article
It is common practice in movies and games to use different actors for the voice and body/face motion of a virtual character. What effect does the combination of these different modalities have on the perception of the viewer? In this paper, we conduct a series of experiments to evaluate the distinctiveness and attractiveness of human motions (face...
Article
Full-text available
Recent evidence suggests that familiarity with an environment may protect against spatial memory decline for familiar objects in older adults. We investigated whether a familiar context also reduces age-related decline in spatial memory for novel objects. Twenty-four younger and 23 older participants viewed a virtual rendering of a local environmen...
Article
Full-text available
Virtual Reality (VR) has emerged as a promising tool in many domains of therapy and rehabilitation, and has recently attracted the attention of researchers and clinicians working with elderly people with MCI, Alzheimer's disease and related disorders. Here we present a study testing the feasibility of using highly realistic image-based rendered VR...
Conference Paper
Full-text available
Crowd simulation has been an active and important area of research in the field of interactive 3D graphics for several decades. However, only recently has there been an increased focus on evaluating the fidelity of the results with respect to real-world situations. The focus to date has been on analyzing the properties of low-level features such as...
Conference Paper
Full-text available
We present a novel algorithm to model density-dependent behaviours in crowd simulation. Previous work has shown that density is a key factor in governing how pedestrians adapt their behaviour. This paper specifically examines, through analysis of real pedestrian data, how density affects how agents control their rate of change of bearing angle with...
Conference Paper
Full-text available
Fear of crowds is a symptom found in agoraphobia (among others) and which has both visual and auditory relevant components. In order to examine the potential interest of auditory-visual virtual reality to treat fear of crowds, we investigated the efficiency of an auditory-visual virtual environment in evoking affective reaction. We conducted an eva...
Conference Paper
Full-text available
All approaches to simulating human collision avoidance for virtual crowds make simplifications to the underlying behaviour. One of the prevalent simplifications is to ignore it's holonomic aspect (i.e. sidestepping, walking backwards). This does not, however, capture the full range of how humans avoid collisions. In real world scenarios we can ofte...
Article
Full-text available
The performance of an interactive virtual crowd system for entertainment purposes can be greatly improved by setting a level-of-details (LOD) strategy: in distant areas, collision avoidance can even be stealthy disabled to drastically speed-up simulation and to handle huge crowds. The greatest difficulty is then to select LODs to progressively simp...
Article
Full-text available
The performance of an interactive virtual crowd system for entertainment purposes can be greatly improved by setting a level-of-details (LOD) strategy: in distant areas, collision avoidance can even be stealthy disabled to drastically speed-up simulation and to handle huge crowds. The greatest difficulty is then to select LODs to progressively simp...
Conference Paper
The performance of an interactive virtual crowd system for entertainment purposes can be greatly improved by setting a level-of-details (LOD) strategy: in distant areas, collision avoidance can even be stealthy disabled to drastically speed-up simulation and to handle huge crowds. The greatest difficulty is then to select LODs to progressively simp...
Article
The seamless integration of virtual characters into dynamic scenes captured by video is a challenging problem. In order to achieve consistent composite results, both the virtual and real characters must share the same geometrical constraints and their interactions must follow some common sense. One essential question is how to detect the motion of...
Article
Full-text available
The seamless integration of virtual characters into dynamic scenes captured by video is a challenging problem. In order to achieve consistent composite results, both the virtual and real characters must share the same geometrical space and their interactions must adhere to the physical coherence criteria. One essential question is how to detect the...
Article
Full-text available
In the everyday exercise of controlling their locomotion, humans rely on their optic flow of the perceived environment to achieve collision-free navigation. In crowds, in spite of the complexity of the environment made of numerous obstacles, humans demonstrate remarkable capacities in avoiding collisions. Cognitive science work on human locomotion...
Conference Paper
Full-text available
Validating that a real user can correctly perceive the motion of a virtual human is first required to enable realistic interactions between real and virtual humans during navigation tasks through virtual reality equipment. In this paper we focus on collision avoidance tasks. Previous works stated that real humans are able to accurately estimate oth...
Conference Paper
Full-text available
An interaction occurs between two humans when they walk with converging trajectories. They need to adapt their motion in order to avoid and cross one another at respectful distance. This paper presents a model for solving interactions between virtual humans. The proposed model is elaborated from experimental interactions data. We first focus our st...
Conference Paper
Full-text available
Until now, moving obstacle avoidance in human walking has been studied through protocols using a mannequin mounted on a rail. The following protocol was designed to study interactions between two real walkers. In this first part, we ask two main questions. What are the conditions for participants to adapt their trajectory, i.e., conditions for an i...

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Projects

Projects (4)
Project
research, develop, pilot and demonstrate a set of professional tools and techniques for making content ‘smarter’, so that it is fully adaptive in a broad, unprecedented manner: adaptive to context (which facilitates re-use), to purpose (among or within industries), to the user (improving the viewing experience), and to the production environment (so that it is ‘future-proof’)