Thomas Pietrzak

3D pointing

Interaction in an immersive environment requires disruptive interaction techniques compared to those usef traditional graphical interfaces. The most common used technique is currently raycasting, a simple ray that makes it possible to select distant targets in a similar way than with a laser pointer. This technique is simple and efficient, but it is very limited when the user would like to select small targets, in particular far away targets.

We present a new technique, by adding a cursor on the ray, that the user can manipulate with an additional degree of freedom. Hence, the nearest target from the cursor is selected when the user performs a validation action. We performed a user study about the visual feedforward, and showed that simply highlighting the nearest target is the best compromise between performance and low visual clutter.
Marc Baloup, Veïs Oudjail, Thomas Pietrzak, Géry Casiez. Techniques de Pointage pour Cibles Distantes en Réalité Virtuelle. In IHM '18, Brest, France, 2018.


FlexStylus is a bendable stylus, which curvature can be mapped to a continuous control, or can be used to navigate a menu. The design takes advantage of three grips: the tool grip, the menu grip and the in-air grip.

Nicholas Fellion, Thomas Pietrzak, Audrey Girouard. FlexStylus: leveraging flexion input for pen interaction. In UIST 2017, Québec, Canada, 2017.


In this project we are interested in latency in input systems. The lagmeter is a device which measures latency, mand makes it possible to slice latency between the moment when a button is pressed or a finger touches a capacitive sensor, and the moment a result appears on the screen. We show that most of latency comes from the display pipeline.
Géry Casiez, Thomas Pietrzak, Damien Marchal, Sébastien Poulmane, Matthieu Falce, Nicolas Roussel. Characterizing Latency in Touch and Button-Equipped Interactive Systems. In UIST 2017, Québec, CANADA, 2017.

Tactile Direct Manipulation

Current tactile displays are essentially used for notifications and assistance. However they are capable of much more, similarly to visual displays with direct manipulation. In this project, we explain how to design direct manipulation with tactile displays.
Aakar Gupta, Thomas Pietrzak, Nicolas Roussel, Ravin Balakrishnan. Direct Manipulation in Tactile Displays. In CHI '16, San Diego, USA, 2016.

Thomas Pietrzak, Nicolas Roussel, Aakar Gupta, Ravin Balakrishnan. Manipulation Dialogique pour Affichages Tactiles. In IHM 2015, Toulouse, France, 2015.

Living Desktop

We frequently move around devices we use on our desk, in order to arrange our working environment. In this project we study the possibility to motorize the keyboard, mouse and screen, and we explore scenarios which take advantage of this augmentation.
Gilles Bailly, Sidarth Sahdev, Sylvain Malacria, Thomas Pietrzak. LivingDesktop: Augmenting Desktop Workstation with Actuated Devices. In CHI '16, San Diego, USA, 2016.


iMore and more people track their activities with sensors. For example they try to motivate themselves to do more physical activity by setting objectives such as a number of steps per day. However their behavior can only change if the person is aware of her progression at a moment she can do exercises. We study the way to encode progression information with a simple smartwatch with an embedded vibrator. We are also interested in the ability of users to interpret this information during their usual activities.
Jessica Cauchard, Janette Cheng, Thomas Pietrzak, James Landay. ActiVibe: Design and Evaluation of Vibrations for Progress Monitoring. In CHI '16, San Diego, USA, 2016.


Keyboard shortcuts on the desktop environment make it possible to select a wide range of commands thanks to combinations of modifier and symbol keys. Modifier keys also make it possible to apply constraints on direct manipulation interactions. Multi-touch interfaces do not have an equivalent, because of a lack of interactive vocabulary. Adoiracourcix uses finger identification for the creation of keyboard shortcuts on multi-touch surfaces.

Alix Goguey, Géry Casiez, Thomas Pietrzak, Daniel Vogel. Adoiraccourcix : Sélection de Commandes sur Écrans Tactiles Multi-Points par Identification des Doigts. In IHM14, Lille, France, 2014.

Alix Goguey, Géry Casiez, Daniel Vogel, Fanny Chevalier, Thomas Pietrzak, Nicolas Roussel. A Three-Step Interaction Pattern for Improving Discoverability in Finger Identification Techniques. In Demo UIST 2014, Honolulu, USA, .

Alix Goguey, Géry Casiez, Thomas Pietrzak, Daniel Vogel, Nicolas Roussel. Adoiraccourcix : Sélection de Commandes sur Écrans Tactiles Multi-Points par Identification des Doigts. In Demo IHM14, Lille, France, .

Alix Goguey, Daniel Vogel, Fanny Chevalier, Thomas Pietrzak, Nicolas Roussel, Géry Casiez. Leveraging finger identification to integrate multi-touch command selection and parameter manipulation. In International Journal of Human-Computer Studies, 99(), 2017. p. 21-36.


Métamorphe is a keyboard with mobile keys. Whether keys are pressed or released, they can be at their usual height, or raised. This allows both to provide haptic eedback to ease eyes-free interaction, and to access the side of the keys. The sides of the keys can be pushed, like the top of the keys. Therefore each key can be mapped to several actions. For instance this could be useful for command selection.

Gilles Bailly, Thomas Pietrzak, Daniel Wigdor, Jonathan Deber. Métamorphe: Augmenting Hotkey Usage with Actuated Keys. In CHI '13, Paris, France, 2013.


S-Notebookis an hybrid system that makes it possible to take note on paper about digital content the user is currently exploring on his mobile device (telephone, tablet, etc.). He can link notes on paper with the content he is currently interacting with, making it possible to reopen it at a later time by tapping the note on his notebook with the digital pen. Therefore he can create bookmarks and hyperlinks on paper notes.
tions papier.
Thomas Pietrzak, Sylvain Malacria, Éric Lecolinet. S-Notebook: Augmenting Mobile Devices with Interactive Paper for Data Management. In AVI 2012, Capri, Italy, 2012. p. 733-736.

Haptic Wristband

The Haptic Wristband is a wireless wearable haptic device. Four vibrators placed around the wrist can be remotely and individually controlled via a bluetooth connexion. Our intent is to explore how subtle background haptic information can be conveyed using this device to the wrist, while the hands are free to perform other manipulations either with another device or in a freehand manner (e.g., with sensors like the Kinect).
Thomas Pietrzak, Ravin Balakrishnan. Haptic Wristband: Wearable and Wireless Haptic Device. In GRAND 2011, Vancouver, Canada, .


U-Note is a system that allows to capture and access the context of a classroom. In class the pupil takes his notes on a notebook. The teacher gives oral explanations, writes on the blackboard, and displays digital documents. The system captures the pupils' notes using an ANOTO digital pen. The explanations, the writings on the blackboard and the actions on the digital documents are captured by the teacher's application. In addition to his notebook, the pupil is given two applications to study his lessons: a mobile application to consult the teacher's documents, and a computer application that completes the notebook for homeworks. This application creates high granularity links between physical and digital documents in order to link pieces of information they contain.
Thomas Pietrzak, Sylvain Malacria, Aurélien Tabard, Éric Lecolinet. What do U-Note? An Augmented Note Taking System for the Classroom. In First workshop on Paper Computing, Papercomp 2010, Copenhagen, Danemark, 2010.

Sylvain Malacria, Thomas Pietrzak, Aurélien Tabard, Éric Lecolinet. U-Note: Capture the Class and Access it Everywhere. In Interact 2011, Lisbon, Portugual, 2011. p. 643-660.

Haptic geometric shapes

Translating graphic objects into tactile objects by mapping dark pixels into raised pins and light pixels into lowered pins is not efficient. The technique we designed allows to explore geometric shapes by guiding the user along the shape with directional Tactons. Thanks to direction and distance information, the user manages to explore an recognize the shape.

Thomas Pietrzak, Andrew Crossan, Stephen A. Brewster, Benoit Martin, Isabelle Pecci. Exploring Geometric Shapes with Touch. In Interact 2009, Uppsala, Sweden, 2009. p. 145-148.

Thomas Pietrzak, Andrew Crossan, Stephen A. Brewster, Benoit Martin, Isabelle Pecci. Exploration de formes géométriques par le toucher. In IHM 2009, Grenoble, France, 2009. p. 251-254.

Architecture multimodale MICOLE

Designing applications intended for visually impaired children is a difficult task. Their impairment restricts display possibilities, so deseigners have to use other modalities like auditory or haptic modalities. The heterogeneity of haptic devices complicates interactions that use multiple devices. the goal of this architecture is to provide components that allows to combine easily heterogeneous devices, and so ease the development of applications. The architecture also allows to include directly interaction techniques that use these devices.

Thomas Pietrzak, Isabelle Pecci, Benoit Martin. Un logiciel d'exploration de schémas de circuits électriques basé sur l'API MICOLE. In Demo IHM 2007, Paris, France, 2007.

Thomas Pietrzak, Benoit Martin, Isabelle Pecci, Rami Saarinen, Roope Raisamo, Janne Jarvi. The MICOLE Architecture: Multimodal Support for Inclusion of Visually Impaired Children . In ICMI 2007, Nagoya, Japan, 2007. p. 193-200.

Haptic electric circuits

Representing schematics for visually impaired people is a difficult problem. Schematics essentially rely on visual properties, and the direct translation of a visual schematic into an haptic representation is not understandable. This work focused of electric circuits schematics, which the main pieces of information are the electric components and the circuit's topology. They have been represented both with PICOB and Tactons, using icons and guidance systems.
Thomas Pietrzak, Nicolas Noble, Isabelle Pecci, Benoit Martin. Evaluation d'un logiciel d'exploration de circuits électriques pour déficients visuels. In RJH-IHM 2006, Anglet, France, 2006.

Thomas Pietrzak, Benoit Martin, Isabelle Pecci. Étude et tests d'une application haptique multimodale pour enfants déficients visuels. In Sciences et Technologies pour le Handicap, 3(1), 2009. p. 37-62.

Pin-array Tactons

There is a great diversity of Tactile sensations. Among them, pressure can be stimulated with pins that translate perpendicularly to the surface of the skin. Several devices are based on pin arrays, and they generally allow to represent letters using the Braille alphabet. Our Tactons are patterns or animations made with raised or lowered pins. The parameters of the signal we identified allow to structure the information displayed on this kind of device.
Thomas Pietrzak, Isabelle Pecci, Benoit Martin. Static and dynamic tactile directional cues experiments with VTPlayer mouse. In Eurohaptics 06, Paris, France, 2006. p. 63-68.

Thomas Pietrzak, Andrew Crossan, Stephen A. Brewster, Benoit Martin, Isabelle Pecci. Creating Usable Pin Array Tactons for Non-Visual Information. In IEEE Transactions on Haptics, 2(2), 2009. p. 61-72.

Haptic post-it by bar codes

Force feedback devices as the PHANToM have many applications. They allow to explore virtual objects thanks to the sense of touch. Haptic feedback can not only be used to increase realism, but also give information when vision is not available. The PICOB project consisted in finding new force feedback interaction techniques allowing to represent structured information. To realize this we use bumps made by a macroscopic deformation of the surface being explored.
Thomas Pietrzak, Benoit Martin, Isabelle Pecci. Affichage d'informations par des impulsions haptiques. In IHM 2005, Toulouse, France, 2005. p. 223-226.

Thomas Pietrzak, Benoit Martin, Isabelle Pecci. Information display by dragged haptic bumps. In Enactive 2005, Genoa, Italy, 2005.