In a psychophysical experiment with 20 participants, we found that designers can introduce unnoticeable offsets between real and virtual rotations of the knob, and we report the corresponding detection thresholds. Based on these, we present the Pseudo-Haptic Resistance technique to convey physical resistance while applying only unnoticeable pseudo-haptic manipulation. Additionally, we provide a first model of how C/D gains correspond to physical resistance perceived during object rotation, and outline how our results can be translated to other rotational manipulations. Finally, we present two example use cases that demonstrate the versatility and power of our approach.

Beyond providing physical capabilities to realize haptic sensations, VoxelHap utilizes VR illusion techniques to expand its haptic resolution. We evaluated the capabilities of the VoxelHap toolkit through the construction of a range of fully functional proxies across a variety of use cases and applications. In two experiments with 24 participants, we investigate a subset of the constructed proxies, studying how they compare to a traditional VR controller. First, we investigated VoxelHap’s combined haptic feedback and second, the trade-offs of using ShapePlates. Our findings show that VoxelHap’s proxies outperform traditional controllers and were favored by participants.

While we found that roughness was significantly affected by compression state, hardness did not seem to follow the same pattern.
In a second study, we focused on two metamaterial patterns showing promise for roughness perception and investigated their visuo-haptic perception in Virtual Reality. Here, eight different compression states of our two selected metamaterials were overlaid with six visual material textures. Our results suggest that, especially at low compression states, our metamaterials were the most promising ones to match the textures displayed to the participants. Additionally, when asked which material participants perceived, adjectives, such as ”broken” and ”damaged” were used. This indicates that metamaterial surface textures could be able to simulate different object states.
Our results underline that metamaterial design is able to extend the gamut of tactile experiences of 3D-printed surfaces structures, as a single sample is able to reconfigure its haptic sensation through compression.

We ran a study with 22 participants, collecting EEG, ECG, EDA, RSP, and interaction data. Our results suggest that EEG and interaction data can be reliably used to detect visuo-motor discrepancies, whereas ECG and RSP seem to suffer from inconsistencies. Our findings also show that participants quickly adapt to large discrepancies, and that they constantly attempt to establish a stable mental model of their environment. Together, these findings suggest that there is no absolute threshold for possible non-detectable discrepancies; instead, it depends primarily on participants’ most recent experience with this kind of interaction.

In the last decades, many different kinds of illusions have been presented in the VR research field; yet, how these illusions feel, mostly remains abstract for the reader. Therefore, we designed and implemented MoVRI, allowing visitors to experience various illusions displayed in exhibition rooms. Visitors can explore the museum by natural locomotion and enter the exhibition rooms they are most interested in. As a result, MoVRI empowers novices and VR experts to experience VR illusions at first hand, that would otherwise remain inaccessible.

The toolkit comes with a pre-installed set of standard questionnaires such as NASA TLX, SSQ and SUS Presence questionnaire. Our system aims to lower the entry barrier to use questionnaires in VR and to significantly reduce development time and cost needed to run pre-, in between- and post-study questionnaires.

The toolkit comes with a pre-installed set of standard questionnaires such as NASA TLX, SSQ and SUS Presence questionnaire. Our system aims to lower the entry barrier to use questionnaires in VR and to significantly reduce development time and cost needed to run pre-, in between- and post-study questionnaires.

The toolkit comes with a pre-installed set of standard questionnaires such as NASA TLX, SSQ and SUS Presence questionnaire. Our system aims to lower the entry barrier to use questionnaires in VR and to significantly reduce development time and cost needed to run pre-, in between- and post-study questionnaires.

TanGi also provides Manipulators allowing users to build objects including movable parts, making them suitable for rich object exploration and manipulation in VR. With a set of different use cases and applications we show the capabilities of the TanGi toolkit and evaluate its use. In a study with 16 participants, we demonstrate that novices can quickly build physical proxy objects using the Composable Shape Primitives and explore how different levels of object embodiment affect virtual object exploration. In a second study with 12 participants we evaluate TanGi’s Manipulators and investigate the effectiveness of embodied interaction. Findings from this study show that TanGi’s proxies outperform traditional controllers and were generally favored by participants.

Existing prototyping approaches, however, have limited tactile output capabilities, require advanced skills for design and fabrication, or are incompatible with curved object geometries. In this paper, we present a novel digital fabrication approach for printing custom, high-resolution controls for electro-tactile output with integrated touch sensing on interactive objects. It supports curved geometries of everyday objects. We contribute a design tool for modeling, testing, and refining tactile input and output at a high level of abstraction, based on parameterized electro-tactile controls. We further contribute an inventory of 10 parametric Tactlet controls that integrate sensing of user input with real-time electro-tactile feedback. We present two approaches for printing Tactlets on 3D objects, using conductive inkjet printing or FDM 3D printing. Empirical results from a psychophysical study and findings from two practical application cases confirm the functionality and practical feasibility of the Tactlets approach.

To understand how this limited perspective affects collaboration, we designed the Remote Manipulator (ReMa), which can reproduce orientation manipulations on a proxy object at a remote site. We conducted two studies with ReMa, with two main findings. First, a shared perspective is more effective and preferred compared to the opposing perspective offered by conventional video chat systems. Second, the physical proxy and video chat complement one another in a combined system: people used the physical proxy to understand object, and used video chat to perform gestures and confirm remote actions.