Author Archives: Adal

“Altering User Movement Behaviour in Virtual Reality” accepted at IEEE VR 2017 and in TVCG!

This paper explores how we can alter Virtual Environments to affect user trajectories in Virtual Environments. See the video:


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A.L. Simeone, I. Mavridou, and W. Powell.
Altering User Movement Behaviour in Virtual Environments
IEEE Transactions on Visualization and Computer Graphics, vol. 19(5), 2017. IEEE, in print..

PDF Version of DocumentVideo

In immersive Virtual Reality systems, users tend to move in a Virtual Environment as they would in an analogous physical environment. In this work, we investigated how user behaviour is affected when the Virtual Environment differs from the physical space. We created two sets of four environments each, plus a virtual replica of the physical environment as a baseline. The first focused on aesthetic discrepancies, such as a water surface in place of solid ground. The second focused on mixing immaterial objects together with those paired to tangible objects. For example, barring an area with walls or obstacles. We designed a study where participants had to reach three waypoints laid out in such a way to prompt a decision on which path to follow based on the conflict between the mismatching visual stimuli and their awareness of the real layout of the room. We analysed their performances to determine whether their trajectories were altered significantly from the shortest route. From the results obtained and our observations, we derive guidelines on how to alter user movement behaviour in Virtual Environments.

Survey on the teaching of 3D Interaction and Virtual reality

As part of a larger project, we are currently running a survey on the teaching of 3D Interaction and Virtual Reality. If you teach courses that are related even marginally to those topics, please consider taking the time to fill the survey.

The full details are reported on the survey’s welcome page. It should not take longer than 10-15 minutes. We will share the results with the community.

You can access the survey here. Thank you!

General Chair for SUI 2017

It’s a great honour to have been chosen as the next General Chair for the ACM Symposium on Spatial User Interaction for 2017. The symposium will take place in Brighton, United Kingdom, together with ACM ISS 2017. Here is my welcome message shown at the closing event of SUI 2016.


ACM Symposium on Spatial User Interaction 2016

I’m happy to report that I have been invited to serve on the ACM SUI 2016 program committee! The conference will be held in Tokyo, on the 15-16 October.

“Three-Point Interaction: Combining Bi-Manual Direct Touch with Gaze” paper accepted at AVI 2016

This paper explores the use of eye gaze as a third channel supporting bimanual touch interaction. We explored whether users can perform three actions in parallel and how effective they are. Results show that for 13% of the time, users acted in complete parallelism. We discuss how three-point user interfaces could benefit from a third channel.

I will be presenting this paper at the ACM Advanced Visual Interfaces Conferences to be held in Bari, Italy this June (7-10), for which I was also chosen to serve as a Program Committee member.


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A.L. Simeone, A. Bulling, J. Alexander, and H. Gellersen.
Three-Point Interaction: Combining Bi-Manual Direct Touch with Gaze
In Proceedings of Advanced Visual Interfaces 2016 (AVI 2016). ACM, pp. 168-175.

PDF Version of DocumentVideo

The benefits of two-point interaction for tasks that require users to simultaneously manipulate multiple entities or dimensions are widely known. Two-point interaction has become common, e.g., when zooming or pinching using two fingers on a smartphone. We propose a novel interaction technique that implements three-point interaction by augmenting two-finger direct touch with gaze as a third input channel. We evaluate two key characteristics of our technique in two multi-participant user studies. In the first, we used the technique for object selection. In the second, we evaluate it in a 3D matching task that requires simultaneous continuous input from fingers and the eyes. Our results show that in both cases participants learned to interact with three input channels without cognitive or mental overload. Participants' performance tended towards fast selection times in the first study and exhibited parallel interaction in the second. These results are promising and show that there is scope for additional input channels beyond two-point interaction.
author={Simeone, Adalberto L., Bulling, Andreas, Alexander, Jason, Gellersen, Hans},
booktitle={Advanced Visual Interfaces 2016},
series = {AVI 2016},
title={Three-Point Interaction: Combining Bi-Manual Direct Touch with Gaze},
pages = {168--175},
numpages = {8},
doi = {10.1145/2909132.2909251},

“Indirect Touch Interaction for Manipulation with Stereoscopic Displays” paper accepted at 3DUI 2016

My full paper on using Indirect Touch multi-touch interaction techniques for stereoscopic displays has been accepted at the IEEE Symposium on 3D User Interfaces 2016, to be held in Greenville, SC, USA.


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A.L. Simeone.
Indirect Touch Manipulation for Interaction with Stereoscopic Displays
In Proceedings of 3D User Interfaces 2016 (3DUI 2016). IEEE, pp. 13-22.

PDF Version of DocumentPresentation SlidesVideo

Research on 3D interaction has explored the application of multi-touch technologies to 3D stereoscopic displays. However, the ability to perceive 3D objects at different depths (in front or behind the screen surface) conflicts with the necessity of expressing inputs on the screen surface. Touching the screen increases the risk of causing the vergence-accommodation conflict which can lead to the loss of the stereoscopic effect or cause discomfort. In this work, we present two studies evaluating a novel approach based on the concept of indirect touch interaction via an external multi-touch device. We compare indirect touch techniques to two state-of-the-art 3D interaction techniques: DS3 and the Triangle Cursor. The first study offers a quantitative and qualitative study of direct and indirect interaction on a 4 DOF docking task. The second presents a follow-up experiment focusing on a 6 DOF docking task. Results show that indirect touch interaction techniques provide a more comfortable viewing experience than both techniques. It also shows that there are no drawbacks when switching to indirect touch, as their performances in terms of net manipulation times are comparable.
author={Simeone, Adalberto L.},
booktitle={3D User Interfaces 2016},
series = {3DUI 2016},
title={Comparing Direct and Indirect Touch in a Stereoscopic Interaction Task},
doi = {10.1109/3DUI.2016.7460025},

Substitutional Reality: bringing Virtual Reality home

The ACM XRDS magazine for students published in its fall issue our article on recent developments on Substitutional Reality. The rest of the issue also contains several interesting articles and perspectives on Virtual Reality!



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A.L. Simeone.
Substitutional Reality: Bringing virtual reality home
In Proceedings of (XRDS 22 (November 2015)). ACM, pp. 24-9.

Now that virtual reality headsets are finally reaching the wider consumer market, how can we merge the physical and virtual worlds to create a unified multi-sensory experience?
title={Substitutional Reality: Bringing virtual reality home},
author={Simeone, Adalberto L. and Velloso, Eduardo},
journal={XRDS: Crossroads, The ACM Magazine for Students},

CHI 2015 Talk on Substitutional Reality now online

I have uploaded the talk I gave on April 23, 2015 in Seoul at the CHI 2015 conference on our research work on Substitutional Reality. It is now online on youtube!

Substitutional Reality: Towards a Research Agenda (WEVR 2015)

The workshop paper on Substitutional Reality published at the IEEE 1st Workshop on Everyday Virtual Reality is now available on the IEEE Xplore library and here (preprint version).


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A.L. Simeone.
Substitutional reality: Towards a research agenda
In Proceedings of 1st Workshop on Everyday Virtual Reality (WEVR 2015). IEEE, pp. 19-22.

PDF Version of Document

In our previous work on Substitutional Reality, we presented an exploration of a class of Virtual Environments where every physical object surrounding the user is associated with appropriate virtual counterparts. Differently from "passive haptics", Substitutional Reality assumes the existence of a discrepancy in the association. This previous work explored how far this mismatch can be pushed and its impact on the believability of the experience. In this paper we discuss three main research directions for Substitutional Reality. Firstly, the design space is largely unexplored as the initial investigation focused on the mismatch between real and virtual objects. Secondly, the development of systems enabling a dynamic substitution process represents a key challenge. Thirdly, we discuss the meta-design process of these experiences..
title={Substitutional reality: Towards a research agenda},
author={Simeone, Adalberto L},
booktitle={1st Workshop on Everyday Virtual Reality (WEVR)},

Substitutional Reality video now online

The video accompanying our research paper on Substitutional Reality is now online on youtube!