Benko H , Holz C , Sinclair M , et al. NormalTouch and TextureTouch: High-fidelity 3D Haptic Shape Rendering on Handheld Virtual Reality Controllers[C]// the 29th Annual Symposium. ACM, 2016.
Abstract
We present an investigation of mechanically-actuated handheld controllers that render the shape of virtual objects through physical shape displacement, enabling users to feel3D surfaces, textures, and forces that match the visual rendering. We demonstrate two such controllers, NormalTouchand TextureTouch. Both controllers are tracked with 6 DOF and produce spatially-registeredhaptic feedback to a user’s finger. NormalTouch haptically renders object surfacesand provides force feedback using a tiltable and extrudable platform. TextureTouch renders the shape of virtual objects including detailed surface structurethrough a 4×4 matrix of actuated pins. By moving our controllers around in space while keeping their finger on the actuated platform, users obtain the impression of a much larger 3D shape by cognitively integrating output sensations over time. Our evaluation compares the effectiveness of our controllers with the two defacto standards in Virtual Reality controllers: device vibration and visual feedback only. We find that haptic feedback significantly increases the accuracy of VR interaction, most effectively by rendering high-fidelity shape output as in the case of our controllers. Participants also generally found NormalTouch and TextureTouch realistic in conveying the sense of touch for a variety of 3D objects.
Contributions
Our paper makes the following four specific contributions:
1. NormalTouch, a handheld controller that renders haptics through an active tiltable and extrudable platform and senses force input from the user upon touch.
2. TextureTouch, a handheld controller that renders the 3D surface structures via a 4×4array of actuated pins.
3. The integration of shape controllers in a VR system as well as a series of solutions to interaction challenges,
such as object penetration and dynamic object behavior.
4. A user study comparing our two controllers with a visual-only and a vibrotactile feedback baseline, showing
gains in accuracy and fidelity of haptic feedback.
Interfaces
Two devices shown in Figure 13 were used to complete the
tasks and we tested four interfaces: NormalTouch, TextureTouch, VibroTactileand VisualOnly.
The VibroTactile interface activated the vibration motor whenever the bottom of
a participant’s finger was within +/- 2mm of the surface, an experience similar to haptic vibration feedback in game controllers
In VisualOnly, the system provided no haptic output or additional visual feedback of any kind, beyond seeing their finger penetrate the surface of the object.
Tasks
Targeting Accuracy Task:During this task, participants were
repeatedly presented with one of the three target types shown
in Figure 15.
Tracing Accuracy Task: During this task, participants followed a 3D path with their fingertip as accurately as possible.
Tracing paths included two straight lines and two curved lines, once appearing flat in front of the participant and once
rotated at a 35° angle (Figure 16).
Fidelity Assessment Task: During this task, participants pressed the clicker, saw each of the high-quality 3D models shown in Figure 17, and explored their shape and surfaces through touch by moving around the controller in the areas marked in red.
Hypotheses
We hypothesized that haptic feedback would increase the
level of fidelity of perceiving virtual objects, resulting in:
H1. Haptic feedback leads to more accurate targeting and tracing compared to VisualOnlyfeedback.
H2. NormalTouchand TextureTouch allow targeting with higher accuracy than VibroTactile, because they render 3D shapes with higher fidelity, facilitating precise touch.
H3. TextureTouch produces the lowest error overall, because it renders structure on the participant’s finger as opposed to
just the surface normal.
H4. Participants complete trials fastest in the Visual Only condition, because no cues other than visual need cognitive
attention and time to process.
Results
Discussion
讨论很详细以后写论文可以参考