Rice University School of Engineering and Computing, Department of Electrical and Computer Engineering

Haptic Interaction ยท UIST 2019

SWISH: A Shifting-Weight Interface of Simulated Hydrodynamics for Haptic Perception of Virtual Fluid Vessels

Authors
Shahabedin Sagheb, Frank Wencheng Liu, Alireza Bahremand, Assegid Kidane, Robert LiKamWa
Venue
UIST 2019 - The 32nd Annual ACM Symposium on User Interface Software and Technology
ACM Digital LibraryBibTeX

SWISH turns a handheld virtual-fluid vessel into a responsive physical object, actively relocating its center of gravity to convey the motion and viscosity of liquid in VR.

Introduction: The Missing Feel of Virtual Fluids

Fluid simulations can look convincing in VR and AR, but their shifting center of gravity is difficult to feel. SWISH is an ungrounded mixed-reality interface designed to give users a realistic haptic sense of liquid behavior inside a vessel.

SWISH shifts a vessel's center of gravity to simulate fluid motion
Figure 1. SWISH actively shifts the vessel's center of gravity as virtual fluid moves.

System Architecture: Coupling Virtual Fluid and Physical Weight

VR tracking and motor actuation relocate the vessel's internal center of gravity in response to simulated hydrodynamics. The implementation couples Nvidia Flex fluid simulation with a 3D-printed augmented vessel and motorized actuation.

SWISH augmented vessel prototype
Figure 2. The augmented handheld vessel.
SWISH hardware and virtual fluid system
Figure 3. Virtual-to-physical coupling in SWISH.

Results: Perceivable Simulated Hydrodynamics

A 24-participant study spanning seven vessel actions and two virtual-fluid viscosities found that users, on average, perceived SWISH's tactile feedback as accurate to the simulated fluid behavior.

SWISH motion path evaluation
Figure 4. Motion-path evaluation of the shifting-weight interface.