Algorithmes, Composants électriques, Sciences et génie, Technologies de l’information et des communications (TIC), Technologies disponibles, Télécommunications


Technique de marche redirigée par rendu avec fovéation pour explorer librement les univers virtuels ouverts

– Description en anglais seulement –

Challenge in virtual reality applications

  • Virtual reality (VR) technology is used in various domains such as gaming, entertainment, education, healthcare and business.
  • Locomotion is one of the most significant unsolved problems in the field of Virtual Reality (VR). To deliver an immersive and comfortable VR experience, the coupling between physical and virtual motions is critically important.
  • Most VR experiences either restrict user movements within limited “room-scale” spaces (e.g. 4mx4m) or utilize alternative virtual locomotion techniques that are widely associated with negative effects such as simulator sickness and spatial disorientation such as flying, teleportation, etc.
  • Redirected walking is a VR locomotion technique which enables users to navigate virtual environments (VEs) that are spatially larger than the available physical tracked space.
  • Limitations of existing techniques, such as warping, introduce visual artifacts and distort the user’s field of view, forcing users to look away by stimulating saccades with the use of flashing spots in screen space, or using accelerated head rotations to redirect the users.
  • These stimulants can be distracting to the user and can result in less immersive user experience.

Novel redirected walking technique

  • The proposed invention does not redirect the user by warping the VE, stimulation saccades, or using accelerated head rotations.
  • This invention is a novel technique for redirected walking in VR based on the psychological phenomenon of inattentional blindness that is induced by the moderated cognitive task at hand.
  • Based on the user’s visual fixation points, the user’s view were divided into zones (Fig. 1).
  • Spatially-varying rotations are applied according to the zone’s importance and are rendered using foveated rendering.
  • It is a real-time technique that is applicable to small and large physical spaces.
  • It does not require the use of stimulated saccades but rather takes advantage of naturally occurring saccades and blinks.
  • Technology developed by Charalambos Poullis, and Yashas Joshi (Department of Computer Science and Software Engineering, Concordia University).

Competitive advantages

  • The technique uses natural visual suppressions such as eye blinks and saccades to make subtle rotations to the VE without the user’s knowledge.
  • The technique does not require any additional or artificial stimulation to trigger the saccades or blinks to make a redirection.
  • Foveated rendering reduces the overall GPU workload and helps achieve real time performance.
  • The technique is indeed effective and can handle long straight walks. This allows users to freely explore open world VEs.

Market applications

  • Virtual reality world where the user needs to explore a VE that is bigger than the available physical tracked space and has moderate cognitive workload.
  • Gaming, training, and simulation in VR.
  • Exploring the real world in applications such as Google Earth or Google Maps in conjunction with any moderate cognitive task.
  • A street view application developed in VR where the user could visit various places virtually around the world.

Business opportunity 

  • Technology available for licensing.
  • Co-development, partnering.
  • Provisional patent application filed.


If you are interested by this technology, please contact :
Jean-Philippe Valois, Director Business Development, Engineering, (514) 575-0425


Concordia University

Main inventors


Charalambos Poullis, Professor, Department of Computer Science and Software Engineering

Prof. POULLIS received the B.Sc. degree (Hons.) in computing and information systems from The University of Manchester, U.K., in 2001, and the M.Sc. degree in computing science with specialization in multimedia and creative technologies and the Ph.D. degree in computer science from the University of Southern California (USC), Los Angeles, USA, in 2003 and 2008, respectively. He is currently an Associate Professor with the Department of Computer Science and Software Engineering, Gina Cody School of Engineering and Computer Science, Concordia University, where he also serves as the Director of the Immersive and Creative Technologies (ICT) Lab. His current research interest includes at the intersection of computer vision and computer graphics. More specifically, he is involved in fundamental and applied research including the following areas feature extraction & classification, acquisition technologies & 3D reconstruction, photo-realistic rendering, and virtual & augmented reality. He is also a Senior Member of the Institute of Electrical and Electronics Engineers (IEEE) Computer Society, and a member of the Association for Computing Machinery (ACM), Marie Curie Alumni Association (MCAA), and British Machine Vision Association (BMVA). He has been serving as a Regular Reviewer in numerous premier conferences and journals, since 2003.


Yashas Joshi, Researcher, Department of Computer Science and Software Engineering

Yashas Joshi received the B.Tech. Degree in electronics and communication engineering from the Vellore Institute of Technology (VIT), Vellore, India, in 2018. He is currently pursuing the M.Sc. degree in computer science with the Immersive and Creative Technologies Lab, Department of Computer Science and Software Engineering, Gina Cody School of Engineering and Computer Science, Concordia University. He specializes in Game Design an Development and is certified by Michigan State University. He also served as a Game Design Instructor in GirlSET Summer School held at Concordia University, in 2019. He is inclined towards applied research with his current research interests being in new interaction and navigation solutions within the context of virtual and augmented reality.