Workshop on Virtual Reality Interactions and Physical Simulations最新文献

{"title":"Level-of-Detail Modal Analysis for Real-time Sound Synthesis","authors":"Dominik Rausch, B. Hentschel, T. Kuhlen","doi":"10.2312/vriphys.20151335","DOIUrl":"https://doi.org/10.2312/vriphys.20151335","url":null,"abstract":"Modal sound synthesis is a promising approach for real-time physically-based sound synthesis. A modal analysis is used to compute characteristic vibration modes from the geometry and material properties of scene objects. These modes allow an efficient sound synthesis at run-time, but the analysis is computationally expensive and thus typically computed in a pre-processing step. In interactive applications, however, objects may be created or modified at run-time. Unless the new shapes are known upfront, the modal data cannot be pre-computed and thus a modal analysis has to be performed at run-time. In this paper, we present a system to compute modal sound data at run-time for interactive applications. We evaluate the computational requirements of the modal analysis to determine the computation time for objects of different complexity. Based on these limits, we propose using different levels-of-detail for the modal analysis, using different geometric approximations that trade speed for accuracy, and evaluate the errors introduced by lower-resolution results. Additionally, we present an asynchronous architecture to distribute and prioritize modal analysis computations.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116171131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deformable Hybrid Approach for Haptic Interaction","authors":"M. Mero, A. Susín","doi":"10.2312/PE/vriphys/vriphys06/008-016","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys06/008-016","url":null,"abstract":"A new hybrid approach for deformable models is presented here and carried out in a virtual reality environment, achieving real time performance with haptic interactions. Our implementation consists in using two approaches for the deformable model. The deformation is modelled using simultaneously a Finite Element Method and a Mesh Free Method. \u0000With this Mesh Free method, particles are used to simulate large deformations in the volume region near the surface of the object. The remaining internal volume of the object can be modelled employing a coarse mesh using the Finite Element Method.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124891970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Medial Surface-Based Real Time Simulation of Elastic Objects","authors":"Matthias Pfaff, C. A. Wüthrich","doi":"10.2312/PE/vriphys/vriphys07/001-010","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys07/001-010","url":null,"abstract":"","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126175859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fast Quadrangular Mass-Spring Systems using Red-Black Ordering","authors":"Pontus Pall, O. Nylén, M. Fratarcangeli","doi":"10.2312/vriphys.20181066","DOIUrl":"https://doi.org/10.2312/vriphys.20181066","url":null,"abstract":"We introduce a practical iterative solver for mass-spring systems which can be trivially mapped to massively parallel architectures, in particular GPUs.We employ our solver for the interactive animation of virtual cloth and show that it is computationally fast, robust and scalable, making it suitable for real-time graphics applications. Under the assumption that the input system is represented by a quadrangular network of masses connected by springs, we first partition the particles into two independent sets. Then, during the animation, the dynamics of all the particles belonging to each set is computed in parallel. This enables a full Gauss-Seidel iteration in just two parallel steps, leading to an approximated solution of large mass-spring systems in a few milliseconds. We use our solver to accelerate the solution of the popular Projective Dynamics framework, and compare it with other common iterative solvers in the current literature.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130299577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Desktop Virtual Reality System with Physical Animation and Glove Interaction","authors":"J. Aleotti, S. Caselli","doi":"10.2312/PE/vriphys/vriphys08/077-082","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys08/077-082","url":null,"abstract":"This paper describes the on-going development of a desktop virtual reality system which offers real-time user interaction and realistic physics-based animation of rigid objects. The system is built upon a graphical engine which supports scene graphs, and a physics-based engine which enables collision detection. Full hand pose estimation is achieved through a dataglove and motion tracker. Motion of the user’s hand is coupled to a 3D model of the human hand. A virtual grasping algorithm ensures stability and allows manipulation tasks to be performed even on complex shapes such as triangle meshes. The system supports ballistic motion of falling objects and models grasped objects with a spring-damper scheme. Moreover, vibratory output is generated as feedback to the user.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127564916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hair, Cloth and Soft Tissues: The Influence of Mechanical Properties on the Real-Time Dynamics of Deformable Objects","authors":"N. Magnenat-Thalmann, Ugo Bonanni, Pascal Volino, L. Assassi","doi":"10.2312/PE/vriphys/vriphys09/039-047","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys09/039-047","url":null,"abstract":"www.eg.org diglib.eg.org Abstract In spite of the impressive advancements achieved during the last years in the domain of interactive physically based simulation, the real-time animation of complex deformable objects still represents a challenge. In order to cope with the resulting computational complexity, researchers continue seeking adequate trade-offs between simulation accuracy and computing performance. One compromise allowing to gain processing power without loosing physical plausibility is selective physically based optimization, i.e. reducing the computations to a predictable amount based on the influence of physical material properties on the mechanical behavior of soft bodies. In this paper, we analyze simulation approaches for structurally different objects and discuss both their specificities and commonalities. We focus on the contribution of physical parameters in the real-time simulation of 1D rods, 2D surfaces and 3D volumes, taking as examples hair, cloth and soft tissues.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"218 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115909528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Introducing Congestion Avoidance into CUDA Based Crowd Simulation","authors":"Falco Wockenfuss, C. Lürig","doi":"10.2312/PE/vriphys/vriphys11/101-110","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys11/101-110","url":null,"abstract":"The simulation of larger crowds of peoples at interactive frames rates get more and more important in games and interactive simulations. Crowds contribute significantly to an immersive urban environment. The nature of the problem where one has to simulate a lot of individuals makes it very accessible for parallelization strategies. As graphics hardware today is a very accessible and powerful parallel computation hardware, the problem lends itself to be adapted to graphics hardware. It is implemented in CUDA in our case. CUDA and other parallel implementations of social force models usually have several numerical and parallelization issues that are finally based on too inhomogeneous population distributions. These are often also undesirable from a game developers point of view. In this paper we introduce the concept of congestion avoidance into the crowd simulator that solves those technical issues and makes the whole simulation also look more natural for gaming applications.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128105890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time Adaptive Approximate SPH","authors":"Prashant Goswami, R. Pajarola","doi":"10.2312/PE/vriphys/vriphys11/019-028","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys11/019-028","url":null,"abstract":"In this paper, we present two different techniques to accelerate and approximate particle-based fluid simulations. The first technique identifies and employs larger time steps than dictated by the CFL condition. The second introduces the concept of approximation in the context of particle advection. For that, the fluid is segregated into active and inactive particles, and a significant amount of computation is saved on the passive particles. Using these two optimization techniques, our approach can achieve up to 7 times speed-up compared to a standard SPH method and it is compatible with other SPH improvement methods. We demonstrate the effectiveness of our method using up to one million particles and also compare it to standard SPH particle simulation visually and statistically.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"53 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113970894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Improved Jacobi Solver for Particle Simulation","authors":"Mihai Frâncu, F. Moldoveanu","doi":"10.2312/vriphys.20141231","DOIUrl":"https://doi.org/10.2312/vriphys.20141231","url":null,"abstract":"AbstractThis paper presents a new method for simulating particles for computer graphics and video games, based onan improved Jacobi solver and a hybrid approach between velocity time stepping and position based dynamics.Current constrained dynamics solvers use relaxation iterative methods like Gauss-Seidel or Jacobi. We proposea new iterative method based on a minimum residual variant of the Conjugate Gradient algorithm and show thatit can be formulated as an improvement to the Jacobi method. We also describe an adaptation of position baseddynamics to better handle contact and friction and allow tight two way coupling with velocity level methods.Categories and Subject Descriptors (according to ACM CCS) : I.3.5 [Computer Graphics]: Computational Geometryand Object Modeling—Physically Based Modeling1. IntroductionParticle systems can be used to model all kind of mechan-ical phenomena including granular matter, fluids, cloth, de-formable objects and even rigid bodies. Granular matter hasbeen used extensively in visual effects and computer gener-ated animations such as Spiderman or Rise of the Guardians[ABC07]. Cloth and soft bodies in general are now ubiqui-tous in movies and becoming more so in games. This is whythe simulation methods still need to become faster and morerobust in order to handle a growing number of objects.In this paper we present a unified approach to simulatinggranular matter and cloth using a constrained dynamics ap-proach. Our hybrid dynamics method offers tight couplingbetween all simulated objects as all constraints are treated inthe same solver loop. Also our improved Jacobi solver showsconvergence similar to the popular Gauss-Seidel method,thus allowing for more efficient parallel implementations.2. Related workGranular matter has been an area of research in computa-tional mechanics for decades. The method of choice is usu-ally the discrete element method (DEM) which treats thegranules as elastic billiard balls. The DEM method was usedin graphics too [BYM05,ATO09,Har07]. Another approachwas a continuum based one, considering the granular mattera special kind of fluid [ZB05,NGL10]. This was followed bya Lagrangian version derived from the smooth particle hy-drodynamics method for simulating fluids [AO11,IWT12].An alternative to DEM is the non-smooth constrained dy-namics approach where the particles are considered fullyrigid and this is the path we are following. In fact the methodwas developed for the more general case of rigid bodies, butthat can be turned into an advantage given the granules canhave any shape other than spherical [BYM05]. A great dealof articles have been written on the subject of multi-body dy-namics with contact and friction [ST96,AH04,AT10,Lac03],many in the computer graphics community [Bar94,Erl07,BETC14,TBV12,KSJP08], and some explicitly on the sub-ject of granular flow [TA10,RA05,LSB10].Rigid bodies can be simulated with other methods thanconstrained dynamics, e.g. the penalty method [BZX14].Other approac","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122111948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SPH Based Shallow Water Simulation","authors":"B. Solenthaler, P. Bucher, N. Chentanez, Matthias Müller, M. Gross","doi":"10.2312/PE/vriphys/vriphys11/039-046","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys11/039-046","url":null,"abstract":"We present an efficient method that uses particles to solve the 2D shallow water equations. These equations describe the dynamics of a body of water represented by a height field. Instead of storing the surface heights using uniform grid cells, we discretize the fluid with 2D SPH particles and compute the height according to the density at each particle location. The particle discretization offers the benefits that it simplifies the use of sparsely filled domains and arbitrary boundary geometry. Our solver can handle terrain slopes and supports two-way coupling of the particle-based height field with rigid objects. An improved surface definition is presented that reduces visible bumps related to the underlying particle representation. It furthermore smoothes areas with separating particles to achieve better rendering results. Both the physics and the rendering are implemented on modern GPUs resulting in interactive performances in all our presented examples.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115098064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}