Six Degrees-of-Freedom Haptic Interaction with Fluids

Abstract

Abstract-We often interact with fluids in our daily life, either through tools such as when holding a glass of water or directly with our body when we swim or we wash our hands. Multimodal interactions with virtual fluids would greatly improve the simulations realism, particularly through haptic interaction. However, achieving realistic, stable and real-time force feedback from fluids is particularly challenging. In this work, we propose a novel approach that allows real-time 6 Degrees of Freedom (DoF) haptic interaction with fluids of variable viscosity. Our haptic rendering technique, based on a Smoothed-Particle Hydrodynamics physical model, provides a realistic haptic feedback through physically-based forces. 6DoF haptic interaction with fluids is made possible thanks to a new coupling scheme and a unified particle model, allowing the use of arbitrary-shaped rigid bodies. Particularly, fluid containers can be created to hold fluid and hence transmit to the user force feedback coming from fluid stirring, pouring, shaking and scooping, to name a few. Moreover, we adapted an existing visual rendering algorithm to meet the frame rate requirements of the haptic algorithms. We evaluate and illustrate the main features of our approach through different scenarios, highlighting the 6DoF haptic feedback and the use of containers.Index Terms-6DoF haptic interaction, computational fluid dynamics, smoothed-particle hydrodynamics, rigid bodies !

Vibrotactile Rendering of Splashing Fluids

“…Rigid bodies are simulated as a constrained set of particles. For further details, we refer the reader to references [23] and [22].…”

“…To simulate the fluid and the bubbles at a scale where the particle radius matches the smallest bubble radius that generates a perceivable vibration (3 mm for a frequency of 1 kHz), we would require approximately four million particles for a cubic meter of fluid. In this case, the computation time would be one order of magnitude greater than current state-of-the art GPU simulations [23]. Since we cannot directly link the particle radius to the resonating bubble radius, we adopt the physically inspired approach of Moss et al [17] to determine the parameters: power laws are used for the distributions of both r and , for which details are provided in the reference [17].…”

“…As the search is executed on the GPU, an iterative implementation is required, with one thread per new bubble neighbor. The search is therefore accelerated on the GPU, leveraging the existing neighbor search algorithms and structures of our SPH framework [23], which efficiently find the neighbors of each particle using the GPU. During our experiments, we required less than five search cycles to account for all the bubbles inside a cavity.…”

“…The vibrotactile model is implemented in PureData, while the SPH fluid and bubble simulation are implemented on GPU [23]. The communication between the SPH simulation and the acoustic model is handled through the Open Sound Control (OSC) protocol.…”

“…We designed three scenarios representing three possible interaction conditions. For the graphic rendering, we used a meshless screen-based technique optimized for high frequency rendering, described in previous work [23]. The scenarios were run on a Core 2 Extreme X7900 processor at 2.8 GHz, with 4 GB of RAM and an Nvidia Quadro FX 3600M GPU with 512 MB of memory.…”