SPH Fluid Tactile Rendering for Ultrasonic Mid-Air Haptics

Description

In our daily lives, we interact with fluids by touching them directly with our hands. Fluids produce a pressure field against the surface of our hands, and we experience fluid dynamics over our skin temporally and spatially at varying pressure distributions depending on fluid properties as well as on the interacting hand's poses and motions. To improve the realism of fluid simulation together with user interaction, we propose a real-time fluid tactile rendering technique that computes the pressure field on a virtual hand surface to be delivered to the user's actual hand via ultrasound-based mid-air haptic display. Our haptic rendering algorithm computes the feedback force in two stages: First, the pressure distribution of the rigid-fluid interaction is computed from a real-time Lagrangian fluid simulation, and then a set of focal points that reflects the generated pressure field is extracted by using a hill-climbing method which gives the local extrema of the pressure field of simulation. We implement a real-time smoothed-particle hydrodynamics fluid simulator and the proposed haptic rendering algorithm using adaptive amplitude modulation approach to demonstrate the effectiveness of our method in fluid tactile rendering in various scenarios.

Figure 1. Fluid tactile rendering with interactive simulation. Our tactile rendering algorithm produces the pressure field from the rigid-fluid interaction. A set of focal points which reflects the rendered pressure field is extracted by GPU hill-climbing method.
Figure 1. Fluid tactile rendering with interactive simulation. Our tactile rendering algorithm produces the pressure field from the rigid-fluid interaction. A set of focal points which reflects the rendered pressure field is extracted by GPU hill-climbing method.

Figure 2. The overview of our fluid tactile rendering method.
Figure 2. The overview of our fluid tactile rendering method.

Figure 3. Local maxima searching with hill-climbing.
Figure 3. Local maxima searching with hill-climbing.

Figure 4. Our haptic rendering results with different interaction scenarios. For each figure, two images of pressure field are shown where the left one is the target pressure field and the right one (blue-boxed) is the final rendered pressure field computed by our proposed algorithm.
Figure 4. Our haptic rendering results with different interaction scenarios. For each figure, two images of pressure field are shown where the left one is the target pressure field and the right one (blue-boxed) is the final rendered pressure field computed by our proposed algorithm.

Online Presentation (IEEE Haptics Symposium 2020)

https://youtu.be/hCRA5dIRS3I

Contact

Jaehyun Jang (jaehyunjang at kaist.ac.kr)

Publications

  • Jaehyun Jang and Jinah Park, “SPH Fluid Tactile Rendering for Ultrasonic Mid-Air Haptics,” IEEE Transactions on Haptics, vol. 13, no. 1, pp. 116–122, Jan. 2020.