We present a method for smoothly blending between existing liquid animations. We introduce a semi-automatic method for matching two existing liquid animations, which we use to create new fluid motion that plausibly interpolates the input. Our contributions include a new space-time non-rigid iterative closest point algorithm that incorporates user guidance, a subsampling technique for efficient registration of meshes with millions of vertices, and a fast surface extraction algorithm that produces 3D triangle meshes from a 4D space-time surface.
Our technique can be used to instantly create hundreds of new simulations, or to interactively explore complex parameter spaces.
Our method is guaranteed to produce output that does not deviate from the input animations, and it generalizes to multiple dimensions. Because our method runs at interactive rates after Nils thuerey thesis initial precomputation step, it has potential applications in games and training simulations.
We explore the connection between fluid capture, simulation and proximal methods, a class of algorithms commonly used for inverse problems in image processing and computer vision. Our key finding is that the proximal operator constraining fluid velocities to be divergence-free is directly equivalent to the pressure-projection methods commonly used in incompressible flow solvers.
This observation lets us treat the inverse problem of fluid tracking as a constrained flow problem all while working in an efficient, modular framework.
In addition it lets us tightly couple fluid simulation into flow tracking, providing a global prior that significantly increases tracking accuracy and temporal coherence as compared to previous techniques.
We demonstrate how we can use these improved results for a variety of applications, such as re-simulation, detail enhancement, and domain modification. We furthermore give an outlook of the applications beyond fluid tracking that our proximal operator framework could enable by exploring the connection of deblurring and fluid guiding.
We introduce a new method for efficiently simulating liquid with extreme amounts of spatial adaptivity. Our method combines several key components to drastically speed up the simulation of large-scale fluid phenomena: We leverage an alternative Eulerian tetrahedral mesh discretization to significantly reduce the complexity of the pressure solve while increasing the robustness with respect to element quality and removing the possibility of locking.
Next, we enable subtle free-surface phenomena by deriving novel second-order boundary conditions consistent with our discretization. We couple this discretization with a spatially adaptive Fluid-Implicit Particle FLIP method, enabling efficient, robust, minimally-dissipative simulations that can undergo sharp changes in spatial resolution while minimizing artifacts.
Along the way, we provide a new method for generating a smooth and detailed surface from a set of particles with variable sizes. Finally, we explore several new sizing functions for determining spatially adaptive simulation resolutions, and we show how to couple them to our simulator.
We combine each of these elements to produce a simulation algorithm that is capable of creating animations at high maximum resolutions while avoiding common pitfalls like inaccurate boundary conditions and inefficient computation. We propose a method of increasing the apparent spatial resolution of an existing liquid simulation.
Previous approaches to this "up-resing" problem have focused on increasing the turbulence of the underlying velocity field. Motivated by measurements in the free surface turbulence literature, we observe that past certain frequencies, it is sufficient to perform a wave simulation directly on the liquid surface, and construct a reduced-dimensional surface-only simulation.
We sidestep the considerable problem of generating a surface parameterization by employing an embedding technique known as the Closest Point Method CPM that operates directly on a 3D extension field.
The CPM requires 3D operators, and we show that for surface operators with no natural 3D generalization, it is possible to construct a viable operator using the inverse Abel transform. We additionally propose a fast, frozen core closest point transform, and an advection method for the extension field that reduces smearing considerably.
Finally, we propose two turbulence coupling methods that seed the high resolution wave simulation in visually expected regions. Buoyant turbulent smoke plumes with a sharp smoke-air interface, such as volcanic plumes, are notoriously hard to simulate.
The surface clearly shows small-scale turbulent structures which are costly to resolve.Sebastian Eberhardt, Steffen Weissmann, Ulrich Pinkall, Nils Thuerey Proceedings of the Symposium on Computer Animation (SCA '12); Eurographics/ACM, Project: [WWW].
This "Cited by" count includes citations to the following articles in Scholar. The ones marked * may be different from the article in the profile.
Real-time Fluid Simulations with Wavelet Turbulence Basil Fierz Master’s Thesis September Prof. Dr. Markus Gross Dr. Nils Thürey Analysis and .
This "Cited by" count includes citations to the following articles in Scholar. The ones marked * may be different from the article in the profile. This "Cited by" count includes citations to the following articles in Scholar.
The ones marked * may be different from the article in the profile. Ben Jones, Nils Thuerey, Tamar Shinar, Adam Bargeil [SIGGRAPH ] Example-Based Plastic Deformation of Rigid Bodies ACM Transactions on Graphics (SIGGRAPH ) volume 35(4),