{"title":"VR Natural Walking in Impossible Spaces","authors":"Daniel Lochner, J. Gain","doi":"10.1145/3487983.3488305","DOIUrl":"https://doi.org/10.1145/3487983.3488305","url":null,"abstract":"Locomotion techniques in Virtual Reality (VR) are the means by which users traverse a Virtual Environment (VE) and are considered an integral and indispensable part of user interaction. This paper investigates the potential that natural walking in impossible spaces provides as a viable locomotion technique in VR when compared to conventional alternatives, such as teleportation, arm-swinging and touchpad/joystick. In this context, impossible spaces are locally Euclidean orbit-manifolds — subspaces separated by portals that are individually consistent but are able to impossibly overlap in space without interacting. A quantitative user experiment was conducted with n = 25 participants, who were asked to complete a set of tasks inside four houses, in each case using a different locomotion technique to navigate. After completing all tasks for a given house, participants were then asked to complete a set of three questionnaires regarding the technique used, namely the Simulator Sickness Questionnaire (SSQ), Game Experience Questionnaire (GEQ) and System Usability Scale (SUS). Time for task completion was also recorded. It was found that natural walking in impossible spaces significantly improves (α = 0.05) immersion (as compared to teleportation and touchpad/joystick, r > 0.7) and system usability (over touchpad/joystick and arm-swinging, r ≥ 0.38), but seems to lead to slower task completion.","PeriodicalId":170509,"journal":{"name":"Proceedings of the 14th ACM SIGGRAPH Conference on Motion, Interaction and Games","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122895302","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":"Catching and Throwing Control of a Physically Simulated Hand","authors":"Yunhao Luo, Kaixiang Xie, S. Andrews, P. Kry","doi":"10.1145/3487983.3488300","DOIUrl":"https://doi.org/10.1145/3487983.3488300","url":null,"abstract":"We design a nominal controller for animating an articulated physics-based human arm model, including the hands and fingers, to catch and throw objects. The controller is based on a finite state machine that defines the target poses for proportional-derivative control of the hand, as well as the orientation and position of the center of the palm using the solution of an inverse kinematics solver. We then use reinforcement learning to train agents to improve the robustness of the nominal controller for achieving many different goals. Imitation learning based on trajectories output by a numerical optimization is used to accelerate the training process. The success of our controllers is demonstrated by a variety of throwing and catching tasks, including flipping objects, hitting targets, and throwing objects to a desired height, and for several different objects, such as cans, spheres, and rods. We also discuss ways to extend our approach so that more challenging tasks, such as juggling, may be accomplished.","PeriodicalId":170509,"journal":{"name":"Proceedings of the 14th ACM SIGGRAPH Conference on Motion, Interaction and Games","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127775248","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}
Bethany Witemeyer, Nicholas J. Weidner, T. Davis, Theodore Kim, S. Sueda
{"title":"QLB: Collision-Aware Quasi-Newton Solver with Cholesky and L-BFGS for Nonlinear Time Integration","authors":"Bethany Witemeyer, Nicholas J. Weidner, T. Davis, Theodore Kim, S. Sueda","doi":"10.1145/3487983.3488297","DOIUrl":"https://doi.org/10.1145/3487983.3488297","url":null,"abstract":"We advocate for the straightforward applications of the Cholesky and the Limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) algorithms in the context of nonlinear time integration of deformable objects with dynamic collisions. At the beginning of each time step, we form and factor the Hessian matrix, accounting for all internal forces while omitting the implicit cross-coupling terms from the collision forces between multiple dynamic objects or self collisions. Then during the nonlinear solver iterations of the time step, we implicitly update this Hessian with L-BFGS. This approach is simple to implement and can be readily applied to any nonlinear time integration scheme, including higher-order schemes and quasistatics. We show that this approach works well in a wide range of settings involving complex nonlinear materials, including heterogeneity and anisotropy, as well as collisions, including frictional contact and self collisions.","PeriodicalId":170509,"journal":{"name":"Proceedings of the 14th ACM SIGGRAPH Conference on Motion, Interaction and Games","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122878914","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 Abbey, Thibault Porssut, B. Herbelin, R. Boulic
{"title":"Assessing the Impact of Mixed Reality Immersion on Presence and Embodiment","authors":"Alexandre Abbey, Thibault Porssut, B. Herbelin, R. Boulic","doi":"10.1145/3487983.3488304","DOIUrl":"https://doi.org/10.1145/3487983.3488304","url":null,"abstract":"When placed inside an immersive virtual simulation, subjects will tend to experience the feeling of being ’really there’ and to respond realistically to their environment, forgetting that it is not real. This behaviour is observed when subjects experience a high sense of presence, the sensation of being in a real place and that the scenario being depicted to them is real. Here we present an experiment designed to evaluate the impact of different levels of immersion, and of different blending of virtual and real objects and body representations, on participant’s subjective experience. Presence is evaluated with an innovative method combining the random introduction of breaks-in-presence (BiP) with a rapid decision-making test. Results show that the level of immersion impacts both the Sense of Presence (SoP) and the Sense of Embodiment (SoE), that the BiP has a limited impact on the SoE without breaking it, and that the level of confidence in the decision test correlates with both the SoP and the SoE.","PeriodicalId":170509,"journal":{"name":"Proceedings of the 14th ACM SIGGRAPH Conference on Motion, Interaction and Games","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130593505","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":"GarMatNet: A Learning-based Method for Predicting 3D Garment Mesh with Parameterized Materials","authors":"Z. Luo, Tianxing Li, T. Kanai","doi":"10.1145/3487983.3488294","DOIUrl":"https://doi.org/10.1145/3487983.3488294","url":null,"abstract":"Recent progress in learning-based methods of garment mesh generation is resulting in increased efficiency and maintenance of reality during the generation process. However, none of the previous works so far have focused on variations in material types based on a parameterized material parameter under static poses. In this work, we propose a learning-based method, GarMatNet, for predicting garment deformation based on the functions of human poses and garment materials while maintaining detailed garment wrinkles. GarMatNet consists of two components: a generally-fitting network for predicting smoothed garment mesh and a locally-detailed network for adding detailed wrinkles based on smoothed garment mesh. We hypothesize that material properties play an essential role in the deformation of garments. Since the influences of material type are relatively smaller than pose or body shape, we employ linear interpolation among different factors to control deformation. More specifically, we apply a parameterized material space based on the mass-spring model to express the difference between materials and construct a suitable network structure with weight adjustment between material properties and poses. The experimental results demonstrate that GarMatNet is comparable to the physically-based simulation (PBS) prediction and offers advantages regarding generalization ability, model size, and training time over the baseline model.","PeriodicalId":170509,"journal":{"name":"Proceedings of the 14th ACM SIGGRAPH Conference on Motion, Interaction and Games","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130486206","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":"Does Synthetic Voice alter Social Response to a Photorealistic Character in Virtual Reality?","authors":"Katja Zibrek, João P. Cabral, R. Mcdonnell","doi":"10.1145/3487983.3488296","DOIUrl":"https://doi.org/10.1145/3487983.3488296","url":null,"abstract":"In this paper, we investigate the effect of a realism mismatch in the voice and appearance of a photorealistic virtual character in virtual reality. While many studies have investigated voice attributes for robots, not much is known about the effect voice naturalness has on the perception of realistic virtual characters. We conducted an experiment in Virtual Reality (VR) with over two hundred participants investigating the mismatch between realistic appearance and unrealistic voice on the feeling of presence, and the emotional response of the user to the character expressing a strong negative emotion (sadness, guilt). We predicted that the mismatched voice would lower social presence and cause users to have a negative emotional reaction and feelings of discomfort towards the character. We found that the concern for the virtual character was indeed altered by the unnatural voice, though interestingly it did not affect social presence.","PeriodicalId":170509,"journal":{"name":"Proceedings of the 14th ACM SIGGRAPH Conference on Motion, Interaction and Games","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128094861","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":"Interactive Viewpoint Exploration for Constructing View-Dependent Models","authors":"Tsukasa Fukusato, Akinobu Maejima","doi":"10.1145/3487983.3488287","DOIUrl":"https://doi.org/10.1145/3487983.3488287","url":null,"abstract":"We introduce an interactive method to sequentially find viewpoints for constructing view-dependent models which represent view-specific deformations in classic 2D cartoons [Chaudhuri et al. 2004, 2007; Koyama and Igarashi 2013; Rademacher 1999]. As users design one view-specific model from a single-fixed viewpoint, the system searches successive viewpoints for subsequent modeling and instantly jumps to the next viewpoints. Thereby, the users can efficiently repeat the design process of view-specific deformations until they are satisfied. This method is simple enough to easily implement in an existing modeling system. We conduct a user study with novice and amateur users and confirm that the proposed system is effective for designing view-specific models envisioned by the users.","PeriodicalId":170509,"journal":{"name":"Proceedings of the 14th ACM SIGGRAPH Conference on Motion, Interaction and Games","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127369140","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}
Alon Flor, Chengguizi Han, Tao Xue, Mridul Aanjaneya
{"title":"Interactive Simulation of Disease Contagion in Dynamic Crowds","authors":"Alon Flor, Chengguizi Han, Tao Xue, Mridul Aanjaneya","doi":"10.1145/3487983.3488298","DOIUrl":"https://doi.org/10.1145/3487983.3488298","url":null,"abstract":"We propose an agent-to-agent contagion-immunity formulation that can simulate detailed COVID-19 spreading within moving crowds. Specifically, we develop a diffusion-based disease contagion model for discrete systems that considers the effect of health interventions, such as social distancing, immunity, and vaccination. We integrate our contagion-immunity formulation with the governing equations of motion for crowd dynamics for investigating the distribution of disease in crowds with different numbers of people. For the same crowd simulation, our model can interactively simulate virus spread for different initial distributions of infected people. To the best of our knowledge, our work is the first to simulate the disease contagion within moving crowds in computer graphics. Our numerical results for the number of infected people in unprotected dense crowds agree with the SIS model, while our model provides richer information for disease spread and shows that vaccination is the best health intervention to prevent infection.","PeriodicalId":170509,"journal":{"name":"Proceedings of the 14th ACM SIGGRAPH Conference on Motion, Interaction and Games","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125825660","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}
R. Dubey, Samuel S. Sohn, J. Abualdenien, Tyler Thrash, C. Hoelscher, A. Borrmann, Mubbasir Kapadia
{"title":"SNAP:Successor Entropy based Incremental Subgoal Discovery for Adaptive Navigation","authors":"R. Dubey, Samuel S. Sohn, J. Abualdenien, Tyler Thrash, C. Hoelscher, A. Borrmann, Mubbasir Kapadia","doi":"10.1145/3487983.3488292","DOIUrl":"https://doi.org/10.1145/3487983.3488292","url":null,"abstract":"Reinforcement learning (RL) has demonstrated great success in solving navigation tasks but often fails when learning complex environmental structures. One open challenge is to incorporate low-level generalizable skills with human-like adaptive path-planning in an RL framework. Motivated by neural findings in animal navigation, we propose a Successor eNtropy-based Adaptive Path-planning (SNAP) that combines a low-level goal-conditioned policy with the flexibility of a classical high-level planner. SNAP decomposes distant goal-reaching tasks into multiple nearby goal-reaching sub-tasks using a topological graph. To construct this graph, we propose an incremental subgoal discovery method that leverages the highest-entropy states in the learned Successor Representation. The Successor Representation encodes the likelihood of being in a future state given the current state and capture the relational structure of states based on a policy. Our main contributions lie in discovering subgoal states that efficiently abstract the state-space and proposing a low-level goal-conditioned controller for local navigation. Since the basic low-level skill is learned independent of state representation, our model easily generalizes to novel environments without intensive relearning. We provide empirical evidence that the proposed method enables agents to perform long-horizon sparse reward tasks quickly, take detours during barrier tasks, and exploit shortcuts that did not exist during training. Our experiments further show that the proposed method outperforms the existing goal-conditioned RL algorithms in successfully reaching distant-goal tasks and policy learning. To evaluate human-like adaptive path-planning, we also compare our optimal agent with human data and found that, on average, the agent was able to find a shorter path than the human participants.","PeriodicalId":170509,"journal":{"name":"Proceedings of the 14th ACM SIGGRAPH Conference on Motion, Interaction and Games","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129521727","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}
Melissa Kremer, Peter Caruana, M. B. Haworth, Mubbasir Kapadia, P. Faloutsos
{"title":"PSM: Parametric Saliency Maps for Autonomous Pedestrians","authors":"Melissa Kremer, Peter Caruana, M. B. Haworth, Mubbasir Kapadia, P. Faloutsos","doi":"10.1145/3487983.3488299","DOIUrl":"https://doi.org/10.1145/3487983.3488299","url":null,"abstract":"Modeling visual attention is an important aspect of simulating realistic virtual humans. This work proposes a parametric model and method for generating real-time saliency maps from the perspective of virtual agents which approximate those of vision-based saliency approaches. The model aggregates a saliency score from user-defined parameters for objects and characters in an agent’s view and uses that to output a 2D saliency map which can be modulated by an attention field to incorporate 3D information as well as a character’s state of attentiveness. The aggregate and parameterized structure of the method allows the user to model a range of diverse agents. The user may also expand the model with additional layers and parameters. The proposed method can be combined with normative and pathological models of the human visual field and gaze controllers, such as the recently proposed model of egocentric distractions for casual pedestrians that we use in our results.","PeriodicalId":170509,"journal":{"name":"Proceedings of the 14th ACM SIGGRAPH Conference on Motion, Interaction and Games","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127285765","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}