ACM Transactions on Graphics最新文献

Resolving Collisions in Dense 3D Crowd Animations 解决密集 3D 人群动画中的碰撞问题

IF 7.8 1区计算机科学

ACM Transactions on Graphics Pub Date : 2024-08-10 DOI: 10.1145/3687266

Gonzalo Gomez-Nogales, Melania Prieto-Martin, Cristian Romero, Marc Comino-Trinidad, Pablo Ramon-Prieto, A. Olivier, Ludovic Hoyet, Miguel Otaduy, J. Pettré, Dan Casas

{"title":"Resolving Collisions in Dense 3D Crowd Animations","authors":"Gonzalo Gomez-Nogales, Melania Prieto-Martin, Cristian Romero, Marc Comino-Trinidad, Pablo Ramon-Prieto, A. Olivier, Ludovic Hoyet, Miguel Otaduy, J. Pettré, Dan Casas","doi":"10.1145/3687266","DOIUrl":"https://doi.org/10.1145/3687266","url":null,"abstract":"We propose a novel contact-aware method to synthesize highly-dense 3D crowds of animated characters. Existing methods animate crowds by, first, computing the 2D global motion approximating subjects as 2D particles and, then, introducing individual character motions without considering their surroundings. This creates the illusion of a 3D crowd, but, with density, characters frequently intersect each other since character-to-character contact is not modeled. We tackle this issue and propose a general method that considers any crowd animation and resolves existing residual collisions. To this end, we take a physics-based approach to model contacts between articulated characters. This enables the real-time synthesis of 3D high-density crowds with dozens of individuals that do not intersect each other, producing an unprecedented level of physical correctness in animations. Under the hood, we model each individual using a parametric human body incorporating a set of 3D proxies to approximate their volume. We then build a large system of articulated rigid bodies, and use an efficient physics-based approach to solve for individual body poses that do not collide with each other while maintaining the overall motion of the crowd. We first validate our approach objectively and quantitatively. We then explore relations between physical correctness and perceived realism based on an extensive user study that evaluates the relevance of solving contacts in dense crowds. Results demonstrate that our approach outperforms existing methods for crowd animation in terms of geometric accuracy and overall realism.","PeriodicalId":50913,"journal":{"name":"ACM Transactions on Graphics","volume":null,"pages":null},"PeriodicalIF":7.8,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141920856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Conditional Mixture Path Guiding for Differentiable Rendering 用于可变渲染的条件混合路径引导

IF 7.8 1区计算机科学

ACM Transactions on Graphics Pub Date : 2024-07-19 DOI: 10.1145/3658133

Zhimin Fan, Pengcheng Shi, Mufan Guo, Ruoyu Fu, Yanwen Guo, Jie Guo

{"title":"Conditional Mixture Path Guiding for Differentiable Rendering","authors":"Zhimin Fan, Pengcheng Shi, Mufan Guo, Ruoyu Fu, Yanwen Guo, Jie Guo","doi":"10.1145/3658133","DOIUrl":"https://doi.org/10.1145/3658133","url":null,"abstract":"The efficiency of inverse optimization in physically based differentiable rendering heavily depends on the variance of Monte Carlo estimation. Despite recent advancements emphasizing the necessity of tailored differential sampling strategies, the general approaches remain unexplored.\u0000 In this paper, we investigate the interplay between local sampling decisions and the estimation of light path derivatives. Considering that modern differentiable rendering algorithms share the same path for estimating differential radiance and ordinary radiance, we demonstrate that conventional guiding approaches, conditioned solely on the last vertex, cannot attain this density. Instead, a mixture of different sampling distributions is required, where the weights are conditioned on all the previously sampled vertices in the path. To embody our theory, we implement a conditional mixture path guiding that explicitly computes optimal weights on the fly. Furthermore, we show how to perform positivization to eliminate sign variance and extend to scenes with millions of parameters.\u0000 To the best of our knowledge, this is the first generic framework for applying path guiding to differentiable rendering. Extensive experiments demonstrate that our method achieves nearly one order of magnitude improvements over state-of-the-art methods in terms of variance reduction in gradient estimation and errors of inverse optimization. The implementation of our proposed method is available at https://github.com/mollnn/conditional-mixture.","PeriodicalId":50913,"journal":{"name":"ACM Transactions on Graphics","volume":null,"pages":null},"PeriodicalIF":7.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141820899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Fully-correlated Anisotropic Micrograin BSDF Model 完全相关的各向异性微晶 BSDF 模型

IF 7.8 1区计算机科学

ACM Transactions on Graphics Pub Date : 2024-07-19 DOI: 10.1145/3658224

Simon Lucas, Mickaël Ribardière, R. Pacanowski, Pascal Barla

引用次数: 0

Smooth Bijective Projection in a High-order Shell 高阶壳中的平滑双射投影

IF 7.8 1区计算机科学

ACM Transactions on Graphics Pub Date : 2024-07-19 DOI: 10.1145/3658207

Shibo Liu, Yang Ji, Jianzhi Guo, Ligang Liu, Xiao-Ming Fu

引用次数: 0

Interactive Design of Stylized Walking Gaits for Robotic Characters 交互式设计机器人角色的风格化行走步态

IF 7.8 1区计算机科学

ACM Transactions on Graphics Pub Date : 2024-07-19 DOI: 10.1145/3658227

Michael A. Hopkins, Georg Wiedebach, Kyle Cesare, Jared Bishop, Espen Knoop, Moritz Bächer

{"title":"Interactive Design of Stylized Walking Gaits for Robotic Characters","authors":"Michael A. Hopkins, Georg Wiedebach, Kyle Cesare, Jared Bishop, Espen Knoop, Moritz Bächer","doi":"10.1145/3658227","DOIUrl":"https://doi.org/10.1145/3658227","url":null,"abstract":"Procedural animation has seen widespread use in the design of expressive walking gaits for virtual characters. While similar tools could breathe life into robotic characters, existing techniques are largely unaware of the kinematic and dynamic constraints imposed by physical robots. In this paper, we propose a system for the artist-directed authoring of stylized bipedal walking gaits, tailored for execution on robotic characters. The artist interfaces with an interactive editing tool that generates the desired character motion in realtime, either on the physical or simulated robot, using a model-based control stack. Each walking style is encoded as a set of sample parameters which are translated into whole-body reference trajectories using the proposed procedural animation technique. In order to generalize the stylized gait over a continuous range of input velocities, we employ a phase-space blending strategy that interpolates a set of example walk cycles authored by the animator while preserving contact constraints. To demonstrate the utility of our approach, we animate gaits for a custom, free-walking robotic character, and show, with two additional in-simulation examples, how our procedural animation technique generalizes to bipeds with different degrees of freedom, proportions, and mass distributions.","PeriodicalId":50913,"journal":{"name":"ACM Transactions on Graphics","volume":null,"pages":null},"PeriodicalIF":7.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141821360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Stylized Rendering as a Function of Expectation 风格化渲染是期望值的函数

IF 7.8 1区计算机科学

ACM Transactions on Graphics Pub Date : 2024-07-19 DOI: 10.1145/3658161

Rex West, Sayan Mukherjee

{"title":"Stylized Rendering as a Function of Expectation","authors":"Rex West, Sayan Mukherjee","doi":"10.1145/3658161","DOIUrl":"https://doi.org/10.1145/3658161","url":null,"abstract":"\u0000 We propose a generalization of the rendering equation that captures both the realistic light transport of physically-based rendering (PBR) and a subset of non-photorealistic rendering (NPR) stylizations in a principled manner. The proposed formulation is based on the key observation that both classical transport and certain NPR stylizations can be modeled as a\u0000 function of expectation.\u0000 Given this observation, we generalize the recursive integrals of the rendering equation to\u0000 recursive functions of expectation.\u0000 As estimating functions of expectation can be challenging, especially recursive ones, we provide a toolkit for unbiased and biased estimation comprising prior work, general strategies, and a novel build-your-own strategy for constructing more complex unbiased estimators from simpler unbiased estimators. We then use this toolkit to construct a complete estimator for the proposed recursive formulation, and implement a sampling algorithm that is both conceptually simple and leverages many of the components of an ordinary path tracer. To demonstrate the practicality of the proposed method we showcase how it captures several existing stylizations like color mapping, cel shading, and cross-hatching, fuses NPR and PBR visuals, and allows us to explore visuals that were previously challenging under existing formulations.\u0000","PeriodicalId":50913,"journal":{"name":"ACM Transactions on Graphics","volume":null,"pages":null},"PeriodicalIF":7.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141821420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cybersickness Reduction via Gaze-Contingent Image Deformation 通过视线相关图像变形减轻晕机症状

IF 7.8 1区计算机科学

ACM Transactions on Graphics Pub Date : 2024-07-19 DOI: 10.1145/3658138

Colin Groth, Marcus A. Magnor, S. Grogorick, Martin Eisemann, P. Didyk

{"title":"Cybersickness Reduction via Gaze-Contingent Image Deformation","authors":"Colin Groth, Marcus A. Magnor, S. Grogorick, Martin Eisemann, P. Didyk","doi":"10.1145/3658138","DOIUrl":"https://doi.org/10.1145/3658138","url":null,"abstract":"Virtual reality has ushered in a revolutionary era of immersive content perception. However, a persistent challenge in dynamic environments is the occurrence of cybersickness arising from a conflict between visual and vestibular cues. Prior techniques have demonstrated that limiting illusory self-motion, so-called vection, by blurring the peripheral part of images, introducing tunnel vision, or altering the camera path can effectively reduce the problem. Unfortunately, these methods often alter the user's experience with visible changes to the content. In this paper, we propose a new technique for reducing vection and combating cybersickness by subtly lowering the screen-space speed of objects in the user's peripheral vision. The method is motivated by our hypothesis that small modifications to the objects' velocity in the periphery and geometrical distortions in the peripheral vision can remain unnoticeable yet lead to reduced vection. This paper describes the experiments supporting this hypothesis and derives its limits. Furthermore, we present a method that exploits these findings by introducing subtle, screen-space geometrical distortions to animation frames to counteract the motion contributing to vection. We implement the method as a realtime post-processing step that can be integrated into existing rendering frameworks. The final validation of the technique and comparison to an alternative approach confirms its effectiveness in reducing cybersickness.","PeriodicalId":50913,"journal":{"name":"ACM Transactions on Graphics","volume":null,"pages":null},"PeriodicalIF":7.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141821771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Capacitive Touch Sensing on General 3D Surfaces 一般三维表面上的电容式触摸感应

IF 7.8 1区计算机科学

ACM Transactions on Graphics Pub Date : 2024-07-19 DOI: 10.1145/3658185

Gianpaolo Palma, Narges Pourjafarian, Jürgen Steimle, Paolo Cignoni

{"title":"Capacitive Touch Sensing on General 3D Surfaces","authors":"Gianpaolo Palma, Narges Pourjafarian, Jürgen Steimle, Paolo Cignoni","doi":"10.1145/3658185","DOIUrl":"https://doi.org/10.1145/3658185","url":null,"abstract":"Mutual-capacitive sensing is the most common technology for detecting multi-touch, especially on flat and simple curvature surfaces. Its extension to a more complex shape is still challenging, as a uniform distribution of sensing electrodes is required for consistent touch sensitivity across the surface. To overcome this problem, we propose a method to adapt the sensor layout of common capacitive multi-touch sensors to more complex 3D surfaces, ensuring high-resolution, robust multi-touch detection. The method automatically computes a grid of transmitter and receiver electrodes with as regular distribution as possible over a general 3D shape. It starts with the computation of a proxy geometry by quad meshing used to place the electrodes through the dual-edge graph. It then arranges electrodes on the surface to minimize the number of touch controllers required for capacitive sensing and the number of input/output pins to connect the electrodes with the controllers. We reach these objectives using a new simplification and clustering algorithm for a regular quad-patch layout. The reduced patch layout is used to optimize the routing of all the structures (surface grooves and internal pipes) needed to host all electrodes on the surface and inside the object's volume, considering the geometric constraints of the 3D shape. Finally, we print the 3D object prototype ready to be equipped with the electrodes. We analyze the performance of the proposed quad layout simplification and clustering algorithm using different quad meshing and characterize the signal quality and accuracy of the capacitive touch sensor for different non-planar geometries. The tested prototypes show precise and robust multi-touch detection with good Signal-to-Noise Ratio and spatial accuracy of about 1mm.","PeriodicalId":50913,"journal":{"name":"ACM Transactions on Graphics","volume":null,"pages":null},"PeriodicalIF":7.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141821893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fabric Tessellation: Realizing Freeform Surfaces by Smocking 织物镶嵌：通过缝制实现自由曲面

IF 7.8 1区计算机科学

ACM Transactions on Graphics Pub Date : 2024-07-19 DOI: 10.1145/3658151

Aviv Segall, Jing Ren, Amir Vaxman, Olga Sorkine-Hornung

引用次数: 0

3D-Layers: Bringing Layer-Based Color Editing to VR Painting 3D 图层：将基于图层的色彩编辑引入 VR 绘画

IF 7.8 1区计算机科学

ACM Transactions on Graphics Pub Date : 2024-07-19 DOI: 10.1145/3658183

Emilie Yu, Fanny Chevalier, Karan Singh, A. Bousseau

{"title":"3D-Layers: Bringing Layer-Based Color Editing to VR Painting","authors":"Emilie Yu, Fanny Chevalier, Karan Singh, A. Bousseau","doi":"10.1145/3658183","DOIUrl":"https://doi.org/10.1145/3658183","url":null,"abstract":"\u0000 The ability to represent artworks as stacks of layers is fundamental to modern graphics design, as it allows artists to easily separate visual elements, edit them in isolation, and blend them to achieve rich visual effects. Despite their ubiquity in 2D painting software, layers have not yet made their way to VR painting, where users paint strokes directly in 3D space by gesturing a 6-degrees-of-freedom controller. But while the concept of a stack of 2D layers was inspired by real-world layers in cell animation, what should 3D layers be? We propose to define\u0000 3D-Layers\u0000 as groups of 3D strokes, and we distinguish the ones that represent 3D geometry from the ones that represent color modifications of the geometry. We call the former\u0000 substrate layers\u0000 and the latter\u0000 appearance layers.\u0000 Strokes in appearance layers modify the color of the substrate strokes they intersect. Thanks to this distinction, artists can define sequences of color modifications as stacks of appearance layers, and edit each layer independently to finely control the final color of the substrate. We have integrated\u0000 3D-Layers\u0000 into a VR painting application and we evaluate its flexibility and expressiveness by conducting a usability study with experienced VR artists.\u0000","PeriodicalId":50913,"journal":{"name":"ACM Transactions on Graphics","volume":null,"pages":null},"PeriodicalIF":7.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141823084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0