{"title":"A double-layer crowd evacuation simulation method based on deep reinforcement learning","authors":"Yong Zhang, Bo Yang, Jianlin Zhu","doi":"10.1002/cav.2280","DOIUrl":"https://doi.org/10.1002/cav.2280","url":null,"abstract":"<p>Existing crowd evacuation simulation methods commonly face challenges of low efficiency in path planning and insufficient realism in pedestrian movement during the evacuation process. In this study, we propose a novel crowd evacuation path planning approach based on the learning curve–deep deterministic policy gradient (LC-DDPG) algorithm. The algorithm incorporates dynamic experience pool and a priority experience sampling strategy, enhancing convergence speed and achieving higher average rewards, thus efficiently enabling global path planning. Building upon this foundation, we introduce a double-layer method for crowd evacuation using deep reinforcement learning. Specifically, within each group, individuals are categorized into leaders and followers. At the top layer, we employ the LC-DDPG algorithm to perform global path planning for the leaders. Simultaneously, at the bottom layer, an enhanced social force model guides the followers to avoid obstacles and follow the leaders during evacuation. We implemented a crowd evacuation simulation platform. Experimental results show that our proposed method has high path planning efficiency and can generate more realistic pedestrian trajectories in different scenarios and crowd sizes.</p>","PeriodicalId":50645,"journal":{"name":"Computer Animation and Virtual Worlds","volume":"35 3","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141187614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"De-NeRF: Ultra-high-definition NeRF with deformable net alignment","authors":"Jianing Hou, Runjie Zhang, Zhongqi Wu, Weiliang Meng, Xiaopeng Zhang, Jianwei Guo","doi":"10.1002/cav.2240","DOIUrl":"https://doi.org/10.1002/cav.2240","url":null,"abstract":"<p>Neural Radiance Field (NeRF) can render complex 3D scenes with viewpoint-dependent effects. However, less work has been devoted to exploring its limitations in high-resolution environments, especially when upscaled to ultra-high resolution (e.g., 4k). Specifically, existing NeRF-based methods face severe limitations in reconstructing high-resolution real scenes, for example, a large number of parameters, misalignment of the input data, and over-smoothing of details. In this paper, we present a novel and effective framework, called <i>De-NeRF</i>, based on NeRF and deformable convolutional network, to achieve high-fidelity view synthesis in ultra-high resolution scenes: (1) marrying the deformable convolution unit which can solve the problem of misaligned input of the high-resolution data. (2) Presenting a density sparse voxel-based approach which can greatly reduce the training time while rendering results with higher accuracy. Compared to existing high-resolution NeRF methods, our approach improves the rendering quality of high-frequency details and achieves better visual effects in 4K high-resolution scenes.</p>","PeriodicalId":50645,"journal":{"name":"Computer Animation and Virtual Worlds","volume":"35 3","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141187630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Screen-space Streamline Seeding Method for Visualizing Unsteady Flow in Augmented Reality","authors":"Hyunmo Kang, JungHyun Han","doi":"10.1002/cav.2250","DOIUrl":"https://doi.org/10.1002/cav.2250","url":null,"abstract":"<p>Streamlines are a popular method of choice in many flow visualization techniques due to their simplicity and intuitiveness. This paper presents a novel streamline seeding method, which is tailored for visualizing unsteady flow in augmented reality (AR). Our method prioritizes visualizing the visible part of the flow field to enhance the flow representation's quality and reduce the computational cost. Being an image-based method, it evenly samples 2D seeds from the screen space. Then, a ray is fired toward each 2D seed, and the on-the-ray point, which has the largest entropy, is selected. It is taken as the 3D seed for a streamline. By advecting such 3D seeds in the velocity field, which is continuously updated in real time, the unsteady flow is visualized more naturally, and the temporal coherence is achieved with no extra efforts. Our method is tested using an AR application for visualizing airflow from a virtual air conditioner. Comparison with the baseline methods shows that our method is suitable for visualizing unsteady flow in AR.</p>","PeriodicalId":50645,"journal":{"name":"Computer Animation and Virtual Worlds","volume":"35 3","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141187629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"PR3D: Precise and realistic 3D face reconstruction from a single image","authors":"Zhangjin Huang, Xing Wu","doi":"10.1002/cav.2254","DOIUrl":"https://doi.org/10.1002/cav.2254","url":null,"abstract":"<p>Reconstructing the three-dimensional (3D) shape and texture of the face from a single image is a significant and challenging task in computer vision and graphics. In recent years, learning-based reconstruction methods have exhibited outstanding performance, but their effectiveness is severely constrained by the scarcity of available training data with 3D annotations. To address this issue, we present the PR3D (Precise and Realistic 3D face reconstruction) method, which consists of high-precision shape reconstruction based on semi-supervised learning and high-fidelity texture reconstruction based on StyleGAN2. In shape reconstruction, we use in-the-wild face images and 3D annotated datasets to train the auxiliary encoder and the identity encoder, encoding the input image into parameters of FLAME (a parametric 3D face model). Simultaneously, a novel semi-supervised hybrid landmark loss is designed to more effectively learn from in-the-wild face images and 3D annotated datasets. Furthermore, to meet the real-time requirements in practical applications, a lightweight shape reconstruction model called fast-PR3D is distilled through teacher–student learning. In texture reconstruction, we propose a texture extraction method based on face reenactment in StyleGAN2 style space, extracting texture from the source and reenacted face images to constitute a facial texture map. Extensive experiments have demonstrated the state-of-the-art performance of our method.</p>","PeriodicalId":50645,"journal":{"name":"Computer Animation and Virtual Worlds","volume":"35 3","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141187613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhigeng Pan, Hongyi Ren, Chang Liu, Ming Chen, Mithun Mukherjee, Wenzhen Yang
{"title":"Design of a lightweight and easy-to-wear hand glove with multi-modal tactile perception for digital human","authors":"Zhigeng Pan, Hongyi Ren, Chang Liu, Ming Chen, Mithun Mukherjee, Wenzhen Yang","doi":"10.1002/cav.2258","DOIUrl":"https://doi.org/10.1002/cav.2258","url":null,"abstract":"<p>Within the field of human–computer interaction, data gloves play an essential role in establishing a connection between virtual and physical environments for the realization of digital human. To enhance the credibility of human-virtual hand interactions, we aim to develop a system incorporating a data glove-embedded technology. Our proposed system collects a wide range of information (temperature, bending, and pressure of fingers) that arise during natural interactions and afterwards reproduce them within the virtual environment. Furthermore, we implement a novel traversal polling technique to facilitate the streamlined aggregation of multi-channel sensors. This mitigates the hardware complexity of the embedded system. The experimental results indicate that the data glove demonstrates a high degree of precision in acquiring real-time hand interaction information, as well as effectively displaying hand posture in real-time using Unity3D. The data glove's lightweight and compact design facilitates its versatile utilization in virtual reality interactions.</p>","PeriodicalId":50645,"journal":{"name":"Computer Animation and Virtual Worlds","volume":"35 3","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141187615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hongyu Li, Meng Yang, Chao Yang, Jianglang Kang, Xiang Suo, Weiliang Meng, Zhen Li, Lijuan Mao, Bin Sheng, Jun Qi
{"title":"Soccer match broadcast video analysis method based on detection and tracking","authors":"Hongyu Li, Meng Yang, Chao Yang, Jianglang Kang, Xiang Suo, Weiliang Meng, Zhen Li, Lijuan Mao, Bin Sheng, Jun Qi","doi":"10.1002/cav.2259","DOIUrl":"https://doi.org/10.1002/cav.2259","url":null,"abstract":"<p>We propose a comprehensive soccer match video analysis pipeline tailored for broadcast footage, which encompasses three pivotal stages: soccer field localization, player tracking, and soccer ball detection. Firstly, we introduce sports camera calibration to seamlessly map soccer field images from match videos onto a standardized two-dimensional soccer field template. This addresses the challenge of consistent analysis across video frames amid continuous camera angle changes. Secondly, given challenges such as occlusions, high-speed movements, and dynamic camera perspectives, obtaining accurate position data for players and the soccer ball is non-trivial. To mitigate this, we curate a large-scale, high-precision soccer ball detection dataset and devise a robust detection model, which achieved the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>m</mi>\u0000 <mi>A</mi>\u0000 <msub>\u0000 <mrow>\u0000 <mi>P</mi>\u0000 </mrow>\u0000 <mrow>\u0000 <mn>50</mn>\u0000 <mo>−</mo>\u0000 <mn>95</mn>\u0000 </mrow>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ mA{P}_{50-95} $$</annotation>\u0000 </semantics></math> of 80.9%. Additionally, we develop a high-speed, efficient, and lightweight tracking model to ensure precise player tracking. Through the integration of these modules, our pipeline focuses on real-time analysis of the current camera lens content during matches, facilitating rapid and accurate computation and analysis while offering intuitive visualizations.</p>","PeriodicalId":50645,"journal":{"name":"Computer Animation and Virtual Worlds","volume":"35 3","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141165050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Graph-based control framework for motion propagation and pattern preservation in swarm flight simulations","authors":"Feixiang Qi, Bojian Wang, Meili Wang","doi":"10.1002/cav.2276","DOIUrl":"https://doi.org/10.1002/cav.2276","url":null,"abstract":"<p>Simulation of swarm motion is a crucial research area in computer graphics and animation, and is widely used in a variety of applications such as biological behavior research, robotic swarm control, and the entertainment industry. In this paper, we address the challenges of preserving structural relations between the individuals in swarm flight simulations by proposing an innovative motion control framework that utilizes a graph-based hierarchy to illustrate patterns within a swarm and allows the swarm to perform flight motions along externally specified paths. In addition, this study designs motion propagation strategies with different focuses for varied application scenarios, analyzes the effects of information transfer latencies on pattern preservation under these strategies, and optimizes the control algorithms at the mathematical level. This study not only establishes a complete set of control methods for group flight simulations, but also has excellent scalability, which can be combined with other techniques in this field to provide new solutions for group behavior simulations.</p>","PeriodicalId":50645,"journal":{"name":"Computer Animation and Virtual Worlds","volume":"35 3","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141165051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"SADNet: Generating immersive virtual reality avatars by real-time monocular pose estimation","authors":"Ling Jiang, Yuan Xiong, Qianqian Wang, Tong Chen, Wei Wu, Zhong Zhou","doi":"10.1002/cav.2233","DOIUrl":"https://doi.org/10.1002/cav.2233","url":null,"abstract":"<div>\u0000 \u0000 <p>Generating immersive virtual reality avatars is a challenging task in VR/AR applications, which maps physical human body poses to avatars in virtual scenes for an immersive user experience. However, most existing work is time-consuming and limited by datasets, which does not satisfy immersive and real-time requirements of VR systems. In this paper, we aim to generate 3D real-time virtual reality avatars based on a monocular camera to solve these problems. Specifically, we first design a self-attention distillation network (SADNet) for effective human pose estimation, which is guided by a pre-trained teacher. Secondly, we propose a lightweight pose mapping method for human avatars that utilizes the camera model to map 2D poses to 3D avatar keypoints, generating real-time human avatars with pose consistency. Finally, we integrate our framework into a VR system, displaying generated 3D pose-driven avatars on Helmet-Mounted Display devices for an immersive user experience. We evaluate SADNet on two publicly available datasets. Experimental results show that SADNet achieves a state-of-the-art trade-off between speed and accuracy. In addition, we conducted a user experience study on the performance and immersion of virtual reality avatars. Results show that pose-driven 3D human avatars generated by our method are smooth and attractive.</p>\u0000 </div>","PeriodicalId":50645,"journal":{"name":"Computer Animation and Virtual Worlds","volume":"35 3","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141165047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"S-LASSIE: Structure and smoothness enhanced learning from sparse image ensemble for 3D articulated shape reconstruction","authors":"Jingze Feng, Chong He, Guorui Wang, Meili Wang","doi":"10.1002/cav.2277","DOIUrl":"https://doi.org/10.1002/cav.2277","url":null,"abstract":"<p>In computer vision, the task of 3D reconstruction from monocular sparse images poses significant challenges, particularly in the field of animal modelling. The diverse morphology of animals, their varied postures, and the variable conditions of image acquisition significantly complicate the task of accurately reconstructing their 3D shape and pose from a monocular image. To address these complexities, we propose S-LASSIE, a novel technique for 3D reconstruction of quadrupeds from monocular sparse images. It requires only 10–30 images of similar breeds for training. To effectively mitigate depth ambiguities inherent in monocular reconstructions, S-LASSIE employs a multi-angle projection loss function. In addition, our approach, which involves fusion and smoothing of bone structures, resolves issues related to disjointed topological structures and uneven connections at junctions, resulting in 3D models with comprehensive topologies and improved visual fidelity. Our extensive experiments on the Pascal-Part and LASSIE datasets demonstrate significant improvements in keypoint transfer, overall 2D IOU and visual quality, with an average keypoint transfer and overall 2D IOU of 59.6% and 86.3%, respectively, which are superior to existing techniques in the field.</p>","PeriodicalId":50645,"journal":{"name":"Computer Animation and Virtual Worlds","volume":"35 3","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141165048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Face attribute translation with multiple feature perceptual reconstruction assisted by style translator","authors":"Shuqi Zhu, Jiuzhen Liang, Hao Liu","doi":"10.1002/cav.2273","DOIUrl":"https://doi.org/10.1002/cav.2273","url":null,"abstract":"<p>Improving the accuracy and disentanglement of attribute translation, and maintaining the consistency of face identity have been hot topics in face attribute translation. Recent approaches employ attention mechanisms to enable attribute translation in facial images. However, due to the lack of accuracy in the extraction of style code, the attention mechanism alone is not precise enough for the translation of attributes. To tackle this, we introduce a style translator module, which partitions the style code into attribute-related and unrelated components, enhancing latent space disentanglement for more accurate attribute manipulation. Additionally, many current methods use per-pixel loss functions to preserve face identity. However, this can sacrifice crucial high-level features and textures in the target image. To address this limitation, we propose a multiple-perceptual reconstruction loss to better maintain image fidelity. Extensive qualitative and quantitative experiments in this article demonstrate significant improvements over state-of-the-art methods, validating the effectiveness of our approach.</p>","PeriodicalId":50645,"journal":{"name":"Computer Animation and Virtual Worlds","volume":"35 3","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141187608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}