Thomas Jund, A. Allaoui, Emmanuelle Darles, Xavier Skapin, P. Meseure, Annie Luciani
{"title":"Mapping Volumetric Meshes to Point-based Motion Models","authors":"Thomas Jund, A. Allaoui, Emmanuelle Darles, Xavier Skapin, P. Meseure, Annie Luciani","doi":"10.2312/PE/vriphys/vriphys12/011-020","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys12/011-020","url":null,"abstract":"Particle-based models produce various, flexible and optimized animations. Intrinsically, they are neither based on a boundary representation nor on volumetric objet meshed representations. Thus, they raise rendering issues since they do not contain enough geometrical information and do not even provide an underlying spatial topology. Consequently, various geometrical shapes can be used to render a motion produced by a meshless model, leading to different visual interpretations. To our knowledge, there is no generic methods to associate any set of points in motion with a topology-based geometric model. In this paper, we propose a framework to map arbitrary volumetric meshes to arbitrary point-based motions and to control the topological changes. Therefore, from only one motion description, different visual results can be obtained. This framework breaks down into three distinct processes: a particles to vertices mapping, the definition of a motion function and the definition of topological modifications and events triggering them. We show how the manipulation of these parameters allows to experiment different mappings for a particular motion and that our framework includes most of previous known mappings.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114347604","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":"Synthesizing Balancing Character Motions","authors":"Ben Kenwright","doi":"10.2312/PE/vriphys/vriphys12/087-096","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys12/087-096","url":null,"abstract":"This paper presents a novel method for generating balancing character poses by means of a weighted inverse kinematic constraint algorithm. The weighted constraints enable us to control the order of priority so that more important conditions such as balancing can take priority over less important ones. Maintaining a balancing pose enables us to create a variety of physically accurate motions (e.g., stepping, crouching). Balancing is achieved by controlling the location of the overall centre of mass of an articulated character; while the secondary constraints generate poses from end-effectors and trajectory information to provide continuous character movement. The poses are created by taking into account physical properties of the articulated character, that include joint mass, size, strength and angular limits. We demonstrate the successfulness of our method by generating balancing postures that are used to produce controllable character motions with physically accurate properties; likewise, our method is computationally fast, flexible and straightforward to implement.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121835599","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":"Real-Time Motion Synthesis for Multiple Goal-Directed Tasks Using Motion Layers","authors":"Christos Mousas, Paul F. Newbury","doi":"10.2312/PE/vriphys/vriphys12/079-085","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys12/079-085","url":null,"abstract":"In this paper, a work in progress approach of layered motion interpolation method for designing realistic animation sequences for multiple goal-directed tasks is presented. The proposed solution is based on the ability to extract and synthesize different motions (in layers), while trying to efficiently reconstruct a natural-looking character's posture in real time. The proposed solution is examined for the case in which running, jumping, and reaching motions are combined. However, in addressing multiple goals fulfilled by a character in complex environments, as well as those involving complex motions, it is necessary to define the best way to handle and reconstruct the information from a motion capture database. Finally, because the character's posture should be as natural looking as possible, a simple centre of mass approach is proposed, to give desirable results at specific time steps","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117194603","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 Implicit Tensor-Mass Solver on the GPU for Soft Bodies Simulation","authors":"X. Faure, F. Zara, F. Jaillet, J-M Moreau","doi":"10.2312/PE/vriphys/vriphys12/001-010","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys12/001-010","url":null,"abstract":"The realistic and interactive simulation of deformable objects has become a challenge in Computer Graphics. In this paper, we propose a GPU implementation of the resolution of the mechanical equations, using a semi-implicit as well as an implicit integration scheme. At the contrary of the classical FEM approach, forces are directly computed at each node of the discretized objects, using the evaluation of the strain energy density of the elements. This approach allows to mix several mechanical behaviors in the same object. Results show a notable speedup of 30, especially in the case of complex scenes. Running times shows that this efficient implementation may contribute to make this model more popular for soft bodies simulations.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131433058","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}
Richard Bezin, Benoît Crespin, Xavier Skapin, O. Terraz, P. Meseure
{"title":"Topological Operations for Geomorphological Evolution","authors":"Richard Bezin, Benoît Crespin, Xavier Skapin, O. Terraz, P. Meseure","doi":"10.2312/PE/vriphys/vriphys11/139-148","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys11/139-148","url":null,"abstract":"Geomorphological processes sculpt the shape of our everyday landscapes and must therefore be simulated to generate plausible digital landscapes. In particular, topological changes must be taken into account during the formation of complex geometries such as natural arches, bridges or tunnels. We present a novel approach to simulate the geomorphological evolution of a 3D terrain represented as a set of volumes stored in a topological model, and describe a set of atomic operations to handle topological events in a robust way. These operations form the basis to successfully implement more complex evolution scenarios in a modelling software based on generalized maps, which could be used to reduce the storage needed by other methods relying on voxel grids or layered data structures.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123493354","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}
Alexandre Peyrat, O. Terraz, S. Mérillou, Eric Galin, D. Ghazanfarpour
{"title":"Generating Large-scale Details: Altering Soil Surface and Structure with Tracks","authors":"Alexandre Peyrat, O. Terraz, S. Mérillou, Eric Galin, D. Ghazanfarpour","doi":"10.2312/PE/vriphys/vriphys11/129-137","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys11/129-137","url":null,"abstract":"Tracks, footsteps and ruts are common elements we can observe in natural sceneries. Wherever there is human activity, we can find marks on the ground left by vehicles or walkers. These marks can be directly dug from a soft ground or left on a hard ground by objects that carry materials on their surfaces. This paper presents a method to alter soil with such tracks. These tracks are defined with a trajectory and the shape of the mark left by the moving object (vehicle or walker) and is then applied to the soil for each step of the trajectory. Using our method we can obtain tracks on a loose soil and the deposit of material through the track on the desired length. This method allows us to produce a great number of large-scale details on terrains.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"203 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133558638","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":"Simulating Inextensible Cloth Using Locking-free Triangle Meshes","authors":"Jan Bender, Raphael Diziol, D. Bayer","doi":"10.2312/PE/vriphys/vriphys11/011-017","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys11/011-017","url":null,"abstract":"This paper presents an efficient method for the dynamic simulation of inextensible cloth. The triangle mesh for our cloth model is simulated using an impulse-based approach which is able to solve hard constraints. Using hard distance constraints on the edges of the triangle mesh removes too many degrees of freedom, resulting in a rigid motion. This is known as the locking problem which is typically solved by using rectangular meshes in existing impulse-based simulations. We solve this problem by using a nonconforming representation for the simulation model which unfortunately results in a discontinuous mesh. Therefore, we couple the original conforming mesh with the nonconforming elements and use it for collision handling and visualization.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132937459","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":"Simulating Human Collision Avoidance Using a Velocity-Based Approach","authors":"Ioannis Karamouzas, M. Overmars","doi":"10.2312/PE/vriphys/vriphys10/125-134","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys10/125-134","url":null,"abstract":"We present a velocity-based model for realistic collision avoidance among virtual characters. Our approach is elaborated from existing experimental data and is based on the simple hypothesis that an individual tries to resolve collisions long in advance by slightly adapting its motion. We have evaluated our model by testing it against a wide range of challenging scenarios. In all of our simulations, the characters exhibit smooth and visually convincing motions, avoiding all collisions with minimal effort. The method reproduces emergent behaviour, like lane formation, that have been observed in real crowds. It is relatively easy to implement and and is fast, allowing the simulation of crowds of thousands of characters in real time.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133538734","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":"Topology-based Physical Simulation","authors":"P. Meseure, Emmanuelle Darles, Xavier Skapin","doi":"10.2312/PE/vriphys/vriphys10/001-010","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys10/001-010","url":null,"abstract":"This paper presents a framework to design mechanical models relying on a topological basis. Whereas naive topological models such as adjacency graphs provide low topological control, the use of efficient topological models such as generalized maps guarantees the quasi-manifold property of the manipulated object: Topological inquiries or changes can be handled robustly and allow the model designer to focus on mechanical aspects. Even if the topology structure is more detailed and consumes more memory, we show that an efficient implementation does not impact computation time and still enables real-time simulation and interaction. We analyze how a simple mass/spring model can be embedded within this framework.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130653235","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 Sub-world Coupling Scheme for Haptic Rendering of Physically-based Rigid Bodies Simulation","authors":"L. Glondu, Maud Marchal, Georges Dumont","doi":"10.2312/PE/vriphys/vriphys09/067-076","DOIUrl":"https://doi.org/10.2312/PE/vriphys/vriphys09/067-076","url":null,"abstract":"In the virtual reality context, the use of haptic rendering as an additional se nsory modality significantly improves the degree of realism of virtual worlds. The physical realism of the intera ction between the user and the objects of the virtual world is particularly important when dealing with contact or collis ion between rigid objects as, for example, in assembly tasks. The high frequency rates required for smoo th manipulations are often difficult to reach, in particular for rigid bodies simulations. Hence, we propose a new coupling scheme based on a dynamic subset of the virtual world, a localized Haptic Sub-World, running at a higher freq uency than the rest of the virtual world. This Sub-World, located around the virtual object manipulated by the user , is synchronized with the virtual world through a dynamic analysis of the interface between the two subsets. Using th is coupling scheme in our software environment, we are able to achieve high frequency haptic rendering usin g sophisticated simulation methods on virtual worlds with a large number of rigid bodies.","PeriodicalId":446363,"journal":{"name":"Workshop on Virtual Reality Interactions and Physical Simulations","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129017575","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}