Abstract
Surface tension has a great influence on the shape of the fluid interface, and is an important physical characteristic in expressing not only liquids but also liquid metals such as mercury and gallium. In the field of physics-based particle fluid simulations, it is a challenging problem to express the high surface tension generated by fluid-air or fluid-solid interaction in real time. The main reasons for this are (1) The magnitude of the force that can be stably expressed in real-time fluid simulation is limited, so when the magnitude of the surface tension increases at a large time-step, the simulation stability decreases, and (2) If we use a small time-step, a stronger force can be expressed. However, it becomes difficult to operate in real time because the computational cost increases. Techniques were proposed to solve this problem for a few specific scenes, but there has not yet been a general approach that can reliably express high surface tension in various scenarios. In this paper, we propose a real-time particle-based fluid simulation framework that can efficiently and stably express high surface tension. Unlike the previous methods, we newly model the surface tension so that the strong surface tension force generated in the droplet area with a large curvature is applied evenly in the normal and tangent directions regardless of the size of the droplet. We also propose new pressure constraints that converge quickly and accurately using this force. Our method can be effectively used in various physics-based simulation scenarios because it can easily express and control surface tension effects that appear in materials such as liquid metal as well as water.
Highlights
Fluid dynamics plays an important role in various fields such as visual effects (VFX) [1,2], games [3,4], forensic investigation [5], and weather prediction/analysis [6,7]
Particle-based fluids techniques such as MPM (Material Point Method) [8,9], FLIP (Fluid-Implict Particle) [10,11,12], APIC (Affine Particle-In-Cell) [13,14], Polynomial PIC [15], and SPH (Smoothed Particle Hydrodynamics) [16,17,18] are useful in creating splashes and expressing free surfaces in detail, so they have been widely used in computer graphics in recent years
Since SPH is sensitive to the number of particles constituting the feature to be expressed, it becomes more difficult to express smallscale thin features when the number of particles around the liquid surface is insufficient in free surface flow
Summary
Fluid dynamics plays an important role in various fields such as visual effects (VFX) [1,2], games [3,4], forensic investigation [5], and weather prediction/analysis [6,7]. We propose two methods to allow the large surface tension to be interactively expressed in SPH: (1) The surface tension is newly modeled so that the strong surface tension forces generated in the droplet area with large curvature can be applied evenly regardless of the size of the droplet, (2) Pressure constraints are modeled to stably represent multiscale surface tension in particle-based fluids. This string shape occurs when the artificial pressure to maintain a constant distance between particles and the pressure force to resist the force coexist in the separated fluid region Due to these artifacts, it is expressed as if the viscosity of the fluid is strong, and especially when applied with surface tension, it often shows an odd appearance due to the coexistence of droplets and string shapes (see Figure 3). The surface tension is newly modeled so that the forces can be applied evenly regardless of the size of the droplet, and we propose pressure constraints that can stably express the multiscale surface tension
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
