TY - JOUR AB - We propose a complete process for designing, simulating, and fabricating synthetic skin for an animatronics character that mimics the face of a given subject and its expressions. The process starts with measuring the elastic properties of a material used to manufacture synthetic soft tissue. Given these measurements we use physicsbased simulation to predict the behavior of a face when it is driven by the underlying robotic actuation. Next, we capture 3D facial expressions for a given target subject. As the key component of our process, we present a novel optimization scheme that determines the shape of the synthetic skin as well as the actuation parameters that provide the best match to the target expressions. We demonstrate this computational skin design by physically cloning a real human face onto an animatronics figure. AU - Bernd Bickel AU - Kaufmann, Peter AU - Skouras, Mélina AU - Thomaszewski, Bernhard AU - Bradley, Derek J AU - Beeler, Thabo AU - Jackson, Philip V AU - Marschner, Steve AU - Matusik, Wojciech AU - Groß, Markus S ID - 2102 IS - 4 JF - ACM Transactions on Graphics TI - Physical face cloning VL - 31 ER - TY - CONF AB - Progress in cloth simulation for computer animation and apparel design has led to a multitude of deformation models, each with its own way of relating geometry, deformation, and forces. As simulators improve, differences between these models become more important, but it is difficult to choose a model and a set of parameters to match a given real material simply by looking at simulation results. This paper provides measurement and fitting methods that allow nonlinear models to be fit to the observed deformation of a particular cloth sample. Unlike standard textile testing, our system measures complex 3D deformations of a sheet of cloth, not just one-dimensional force-displacement curves, so it works under a wider range of deformation conditions. The fitted models are then evaluated by comparison to measured deformations with motions very different from those used for fitting. AU - Miguel, Eder AU - Bradley, Derek J AU - Thomaszewski, Bernhard AU - Bernd Bickel AU - Matusik, Wojciech AU - Otaduy, Miguel A AU - Marschner, Steve ID - 2106 IS - 2 TI - Data-driven estimation of cloth simulation models VL - 31 ER - TY - CONF AB - In recent years, various methods have been introduced to exploit pre-recorded data to improve the performance and/or realism of dynamic deformations, but their differences and similarities have not been adequately analyzed or discussed. So far, the proposed methods have been explored mainly in the research context. They have not been adopted by the computer graphics industry. This course bridges the gap between research labs and industry to present a unifying theory and understanding of data-driven methods for dynamic deformations that may inspire development of novel solutions. It focuses on application of data-driven methods to three areas of computer animation: dynamic deformation of faces, soft volumetric tissue, and cloth. And it describes how to approach these challenges in a data-driven manner, classifies the various methods, and demonstrates how data-driven methods can work in other settings. AU - Otaduy, Miguel A AU - Bernd Bickel AU - Bradley, Derek J AU - Wang, Huamin ID - 2104 TI - Data-driven simulation methods in computer graphics: Cloth, tissue and faces ER - TY - CONF AU - Skouras, Mélina AU - Thomaszewski, Bernhard AU - Bernd Bickel AU - Groß, Markus S ID - 2105 IS - 2 TI - Computational design of rubber balloons VL - 31 ER - TY - JOUR AB - We consider a class of stochastic PDEs of Burgers type in spatial dimension 1, driven by space–time white noise. Even though it is well known that these equations are well posed, it turns out that if one performs a spatial discretization of the nonlinearity in the “wrong” way, then the sequence of approximate equations does converge to a limit, but this limit exhibits an additional correction term. This correction term is proportional to the local quadratic cross-variation (in space) of the gradient of the conserved quantity with the solution itself. This can be understood as a consequence of the fact that for any fixed time, the law of the solution is locally equivalent to Wiener measure, where space plays the role of time. In this sense, the correction term is similar to the usual Itô–Stratonovich correction term that arises when one considers different temporal discretizations of stochastic ODEs. AU - Hairer, Martin M AU - Jan Maas ID - 2125 IS - 4 JF - Annals of Probability TI - A spatial version of the Itô-Stratonovich correction VL - 40 ER - TY - JOUR AB - We study a new notion of Ricci curvature that applies to Markov chains on discrete spaces. This notion relies on geodesic convexity of the entropy and is analogous to the one introduced by Lott, Sturm, and Villani for geodesic measure spaces. In order to apply to the discrete setting, the role of the Wasserstein metric is taken over by a different metric, having the property that continuous time Markov chains are gradient flows of the entropy. Using this notion of Ricci curvature we prove discrete analogues of fundamental results by Bakry–Émery and Otto–Villani. Further, we show that Ricci curvature bounds are preserved under tensorisation. As a special case we obtain the sharp Ricci curvature lower bound for the discrete hypercube. AU - Erbar, Matthias AU - Jan Maas ID - 2127 IS - 3 JF - Archive for Rational Mechanics and Analysis TI - Ricci curvature of finite Markov chains via convexity of the entropy VL - 206 ER - TY - JOUR AB - We introduce a technique for handling Whitney decompositions in Gaussian harmonic analysis and apply it to the study of Gaussian analogues of the classical tent spaces T 1,q of Coifman–Meyer–Stein. AU - Jan Maas AU - van Neerven, Jan M AU - Portal, Pierre ID - 2128 IS - 2 JF - Arkiv för Matematik TI - Whitney coverings and the tent spaces T 1,q (γ) for the Gaussian measure VL - 50 ER - TY - JOUR AB - We show that the electric dipole-dipole interaction between a pair of polar molecules undergoes an all-out transformation when superimposed by a far-off-resonant optical field. The combined interaction potential becomes tunable by variation of wavelength, polarisation and intensity of the optical field and its dependence on the intermolecular separation exhibits a crossover from an inverse-power to an oscillating behaviour. The ability thereby offered to control molecular interactions opens up avenues toward the creation and manipulation of novel phases of ultracold polar gases among whose characteristics is a long-range entanglement of the dipoles' mutual orientation. We devised an accurate analytic model of such optical-field-dressed dipole-dipole interaction potentials, which enables a straightforward access to the optical-field parameters required for the design of intermolecular interactions in the laboratory. AU - Mikhail Lemeshko AU - Friedrich, Břetislav ID - 2203 IS - 15-16 JF - Molecular Physics TI - Interaction between polar molecules subject to a far-off-resonant optical field: Entangled dipoles up- or down-holding each other VL - 110 ER - TY - JOUR AB - We study the growth dynamics of ordered structures of strongly interacting polar molecules in optical lattices. Using a dipole blockade of microwave excitations, we map the system onto an interacting spin-1/2 model possessing ground states with crystalline order, and describe a way to prepare these states by nonadiabatically driving the transitions between molecular rotational levels. The proposed technique bypasses the need to cross a phase transition and allows for the creation of ordered domains of considerably larger size compared to approaches relying on adiabatic preparation. AU - Lemeshko, Mikhail AU - Krems, Roman AU - Weimer, Hendrik ID - 2201 IS - 3 JF - Physical Review Letters TI - Nonadiabatic preparation of spin crystals with ultracold polar molecules VL - 109 ER - TY - JOUR AB - We propose a method for sensitive parallel detection of low-frequency electromagnetic fields based on the fine structure interactions in paramagnetic polar molecules. Compared to the recently implemented scheme employing ultracold 87Rb atoms by Böhi, the technique based on molecules offers a 100-fold higher sensitivity, the possibility to measure both the electric and magnetic field components, and a probe of a wide range of frequencies from the dc limit to the THz regime. AU - Alyabyshev, Sergey V AU - Mikhail Lemeshko AU - Krems, Roman V ID - 2202 IS - 1 JF - Physical Review A - Atomic, Molecular, and Optical Physics TI - Sensitive imaging of electromagnetic fields with paramagnetic polar molecules VL - 86 ER -