Character Motion Research Articles

Effects of Specific RAMP Protocol Phase on Change of Direction Speed of Police Students.

Background: This study assessed the effects of two distinct RAMP (Raise, Activate, Mobilize, Potentiate) protocols, mobility-focused and reactiveness-focused, on change of direction speed in police students (i.e., tactical athletes). Methods: A longitudinal design with two experimental and one control group was employed. The study sample consisted of 39 police students (aged 19.2 ± 0.2 yrs) who were randomly allocated into three equal groups of 13 participants (7 females and 6 males). Experimental groups were labeled as the mobility group or reactiveness group based on the type of RAMP protocol they performed. During the tactical physical education classes, the mobility group performed four complex mobility exercises, while the reactiveness group performed four exercises for trunk reactiveness. After the specific warm-up, both groups continued with syllabus activities. The control group performed only regular activities based on the study syllabus. All participants performed the Illinois Agility test unloaded (IAT) and loaded (10 kg vest [IATL]) and Functional Movement Screening (FMS) before and after 8 weeks of the applied protocols. Results: In general, improvements were observed across all participants in the IAT (p < 0.001), IATL (p < 0.001), and FMS (p < 0.001). The mobility protocol had a more substantial impact compared to the reactiveness protocol on the IAT (d = 0.55 vs. d = 0.40), IATL (d = 0.44 vs. d = 0.38), and FMS (d = 0.88 vs. d = -0.42). Additionally, the control group, which did not follow either RAMP protocol, did not show significant improvements. Conclusions: These results underscore the importance of incorporating targeted mobility training in the limited time available for strength and conditioning programs, as it improves occupationally relevant movement qualities such as change of direction speed ability. Prioritizing mobility training in young tactical athletes may offer broader benefits compared to reactiveness training.

Garment Animation NeRF with Color Editing

AbstractGenerating high‐fidelity garment animations through traditional workflows, from modeling to rendering, is both tedious and expensive. These workflows often require repetitive steps in response to updates in character motion, rendering viewpoint changes, or appearance edits. Although recent neural rendering offers an efficient solution for computationally intensive processes, it struggles with rendering complex garment animations containing fine wrinkle details and realistic garment‐and‐body occlusions, while maintaining structural consistency across frames and dense view rendering. In this paper, we propose a novel approach to directly synthesize garment animations from body motion sequences without the need for an explicit garment proxy. Our approach infers garment dynamic features from body motion, providing a preliminary overview of garment structure. Simultaneously, we capture detailed features from synthesized reference images of the garment's front and back, generated by a pre‐trained image model. These features are then used to construct a neural radiance field that renders the garment animation video. Additionally, our technique enables garment recoloring by decomposing its visual elements. We demonstrate the generalizability of our method across unseen body motions and camera views, ensuring detailed structural consistency. Furthermore, we showcase its applicability to color editing on both real and synthetic garment data. Compared to existing neural rendering techniques, our method exhibits qualitative and quantitative improvements in garment dynamics and wrinkle detail modeling. Code is available at https://github.com/wrk226/GarmentAnimationNeRF.

Pose‐to‐Motion: Cross‐Domain Motion Retargeting with Pose Prior

AbstractCreating plausible motions for a diverse range of characters is a long‐standing goal in computer graphics. Current learning‐based motion synthesis methods rely on large‐scale motion datasets, which are often difficult if not impossible to acquire. On the other hand, pose data is more accessible, since static posed characters are easier to create and can even be extracted from images using recent advancements in computer vision. In this paper, we tap into this alternative data source and introduce a neural motion synthesis approach through retargeting, which generates plausible motion of various characters that only have pose data by transferring motion from one single existing motion capture dataset of another drastically different characters. Our experiments show that our method effectively combines the motion features of the source character with the pose features of the target character, and performs robustly with small or noisy pose data sets, ranging from a few artist‐created poses to noisy poses estimated directly from images. Additionally, a conducted user study indicated that a majority of participants found our retargeted motion to be more enjoyable to watch, more lifelike in appearance, and exhibiting fewer artifacts. Our code and dataset can be accessed here.

PartwiseMPC: Interactive Control of Contact‐Guided Motions

AbstractPhysics‐based character motions remain difficult to create and control. We make two contributions towards simpler specification and faster generation of physics‐based control. First, we introduce a novel partwise model predictive control (MPC) method that exploits independent planning for body parts when this proves beneficial, while defaulting to whole‐body motion planning when that proves to be more effective. Second, we introduce a new approach to motion specification, based on specifying an ordered set of contact keyframes. These each specify a small number of pairwise contacts between the body and the environment, and serve as loose specifications of motion strategies. Unlike regular keyframes or traditional trajectory optimization constraints, they are heavily under‐constrained and have flexible timing. We demonstrate a range of challenging contact‐rich motions that can be generated online at interactive rates using this framework. We further show the generalization capabilities of the method.

Computational account for the naturalness perception of others' jumping motion based on a vertical projectile motion model.

The visual naturalness of a rendered character's motion is an important factor in computer graphics work, and the rendering of jumping motions is no exception to this. However, the computational mechanism that underlies the observer's judgement of the naturalness of a jumping motion has not yet been fully elucidated. We hypothesized that observers would perceive a jumping motion as more natural when the jump trajectory was consistent with the trajectory of a vertical projectile motion based on Earth's gravity. We asked human participants to evaluate the naturalness of point-light jumping motions whose height and duration were modulated. The results showed that the observers' naturalness rating varied with the modulation ratios of the jump height and duration. Interestingly, the ratings were high even when the height and duration differed from the actual jump. To explain this tendency, we constructed computational models that predicted the theoretical trajectory of a jump based on the projectile motion formula and calculated the errors between the theoretical and observed trajectories. The pattern of the errors correlated closely with the participants' ratings. Our results suggest that observers judge the naturalness of observed jumping motion based on the error between observed and predicted jump trajectories.

A mindful body approach to creating architecture: movement, models and spatial experiences.

If architecture is an expression of human creativity through multi-sensory embodiment, then learning, creating and experiencing architecture should also be multi-sensory and embodied. In this article, we challenge the separation of mind and body through Sheets-Johnstone's mindful bodies concept. We define a mindful body in architecture as one that documents, analyses and memory maps the moving body in different qualities of movement to create diverse spatial experiences. A mindful body approach to creating architecture involves: (i) engaging in meaningful movement and documenting the body, (ii) documenting embodied interactions with dynamic, animate elements in the built environment, (iii) connecting our body's movements with emotions and memories, (iv) designing spaces that produce diverse movements and atmospheres, and (v) designing architecture based on these spaces. We hypothesize that if designers engage in a mindful body approach to design, they can create spatial experiences that help us make sense of ourselves, others and the world. A mindful body approach to design can result in architectural spaces that activate our attentional switches, connect haptic experiences and memories and reveal wonders. This article is part of the theme issue 'Minds in movement: embodied cognition in the age of artificial intelligence'.

Resolving Collisions in Dense 3D Crowd Animations

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.

Critiquing Indian Middle‐Class Principles of Mobility: Examining Transgender Representation in Post‐Millennial OTT Media in India

ABSTRACTThis literature review critically examines the need to incorporate critiques of urban, middle‐class, Hindu, upper‐caste mediated regulation of transgender mobility within media analyses of transgender representation in contemporary films and other streaming (OTT) media in India. The essay explores how the real and imagined/narrative mobility of marginalized groups, such as Dalit women, Muslim women, sex workers, and transgender communities, has been historically disciplined by the cultural and political practices of the upper‐caste Hindu middle class family. Material‐discursive practices of this class upper‐caste, middle‐class Hindu family shape and get shaped by gendered and caste‐coded interests of neoliberal productivity and heteropatriarchal respectability, determining the ideal geographies of the city and the relational cartographies of the nation. Films and media also get influenced by and shape these discursive practices by prioritizing a middle‐class sense of place in their worldmaking efforts. The narrative schema of such cultural production designs the movement of characters in such a way that they move in directions considered recognizable, legible and acceptable for the Indian middle class family. The primary aim of this review is to delineate the literature on spatial imaginaries of the middle class family and how the cultural practices of this class imagine and render legible the marginalized, allowing for a critical analysis of the co‐production of middle‐class spatial control and transgender visibility in cultural texts like that of contemporary streaming media. Furthermore, this study explores the emplacement of the marginalized as evident in critiques of representations of Dalit, Muslim, and sex worker communities in Indian cinema, emphasizing the necessity of applying similar analyses to trans representation. This spatially sensitive critique is crucial for understanding transgender struggles in India, highlighting the importance of examining middle‐class spatial imaginaries that shape trans representation and the politics of regulated transgender (im)mobilities.

Interactive Design of Stylized Walking Gaits for Robotic Characters

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.

Categorical Codebook Matching for Embodied Character Controllers

Translating motions from a real user onto a virtual embodied avatar is a key challenge for character animation in the metaverse. In this work, we present a novel generative framework that enables mapping from a set of sparse sensor signals to a full body avatar motion in real-time while faithfully preserving the motion context of the user. In contrast to existing techniques that require training a motion prior and its mapping from control to motion separately, our framework is able to learn the motion manifold as well as how to sample from it at the same time in an end-to-end manner. To achieve that, we introduce a technique called codebook matching which matches the probability distribution between two categorical codebooks for the inputs and outputs for synthesizing the character motions. We demonstrate this technique can successfully handle ambiguity in motion generation and produce high quality character controllers from unstructured motion capture data. Our method is especially useful for interactive applications like virtual reality or video games where high accuracy and responsiveness are needed.

A Real-time Motion Capture System for 3-D Virtual Characters

Motion tracking method is being issued as essential part of the entertainment, medical, sports, education and industry with the development of 3-D virtual reality. Virtual human character in the digital animation and game application has been controlled by interfacing devices; mouse, joysticks, midi-slider, and so on. Those devices could not enable virtual human character to move smoothly and naturally. Furthermore, high-end human motion capture systems in commercial market are expensive and complicated. In this paper, we proposed a practical and fast motion capturing system consisting of optic sensors, and linked the data with 3-D game character with real time. The prototype experiment setup is successfully applied to a boxing game which requires very fast movement of human character

CSS for CVR: A Reciprocal Velocity Obstacle-Based Crowd Simulation System for Non-Playable Character Movement of Campus Virtual Reality

Along with the development of multimedia technology, an overview of the campus environment for prospective new visitors can be visualized through a 3D virtual environment based on virtual reality. A crowd simulation system is needed to provide an overview of the crowds in campus virtual reality (CVR). The simulation helps make it easier for individuals to predict crowds in certain areas virtually. In this study, we propose using the Reciprocal Velocity Obstacle (RVO) method to support the simulation of Non-Playable Character (NPC) crowds in a visualized virtual environment. RVO implements multi-agent navigation by estimating the possibility of moving without communication between agents and being able to perform collision avoidance. The use of RVO in this study aims to contribute to the collision detection development process for each NPC. The application of RVO is carried out in the development of virtual reality by using Unity3D and Blender asset support tools. The results of this study indicate that the RVO method can be applied in multi-agent navigation. These results were confirmed by the success of the NPC as a simulation agent in selecting routes and independently navigating to avoid collisions between agents without the need for communication. In every simulation, collisions will occur within a set of agents due to high density, which causes complex computations. The development of CSS can help every CVR user experience a virtual environment. In addition, each user can experience a more natural experience with the presence of 3D objects and virtual reality with RVO-based CSS. Furthermore, this research material is expected to be developed from various perspectives and themes related to crowd simulation for games and other simulation media.

Cartoon copyright recognition method based on character personality action

Aiming at the problem of cartoon piracy and plagiarism, this paper proposes a method of cartoon copyright recognition based on character personality actions. This method can be used to compare the original cartoon actions with the action characteristics of pirated or copied cartoons to identify whether there is piracy or plagiarism. Firstly, an image preprocessing scheme for character extraction is designed. GrabCut interactive image segmentation algorithm was used to obtain cartoon characters, and then binarization and morphological processing were performed on the results. Secondly, a feature extraction scheme based on character profile, moving character and character pose is designed. By extracting the perimeter and area of the character contour, the length-to-width ratio of the smallest rectangle and the inclination angle of the contour, the character contour features are obtained. The three-dimensional coordinates are established by the central point position of the cartoon character in the two-dimensional image and the change of the character's zoom in and out, and the character's motion angle characteristics are calculated. By skeletonizing a character to obtain the pose characteristics, and using deburring operation to remove redundant branches, then extract the skeleton joint angle information. Finally, feature fusion is performed on the extracted features. The experimental results show that the proposed method breaks the limitation of the conventional single feature based recognition, and can better extract the character features including contour feature, motion feature and pose feature through multi-feature based extraction, so as to protect the cartoon copyright.

A language‐directed virtual human motion generation approach based on musculoskeletal models

AbstractThe development of the systems capable of synthesizing natural and life‐like motions for virtual characters has long been a central focus in computer animation. It needs to generate high‐quality motions for characters and provide users with a convenient and flexible interface for guiding character motions. In this work, we propose a language‐directed virtual human motion generation approach based on musculoskeletal models to achieve interactive and higher‐fidelity virtual human motion, which lays the foundation for the development of language‐directed controllers in physics‐based character animation. First, we construct a simplified model of musculoskeletal dynamics for the virtual character. Subsequently, we propose a hierarchical control framework consisting of a trajectory tracking layer and a muscle control layer, obtaining the optimal control policy for imitating the reference motions through the training. We design a multi‐policy aggregation controller based on large language models, which selects the motion policy with the highest similarity to user text commands from the action‐caption data pool, facilitating natural language‐based control of virtual character motions. Experimental results demonstrate that the proposed approach not only generates high‐quality motions highly resembling reference motions but also enables users to effectively guide virtual characters to perform various motions via natural language instructions.

Multi‐scale edge aggregation mesh‐graph‐network for character secondary motion

AbstractAs an enhancement to skinning‐based animations, light‐weight secondary motion method for 3D characters are widely demanded in many application scenarios. To address the dependence of data‐driven methods on ground truth data, we propose a self‐supervised training strategy that is free of ground truth data for the first time in this domain. Specifically, we construct a self‐supervised training framework by modeling the implicit integration problem with steps as an optimization problem based on physical energy terms. Furthermore, we introduce a multi‐scale edge aggregation mesh‐graph block (MSEA‐MG Block), which significantly enhances the network performance. This enables our model to make vivid predictions of secondary motion for 3D characters with arbitrary structures. Empirical experiments indicate that our method, without requiring ground truth data for model training, achieves comparable or even superior performance quantitatively and qualitatively compared to state‐of‐the‐art data‐driven approaches in the field.

Introducing a New Method for Studying the Effects of Movement Synchrony in Virtual Reality.

This study introduces a new method to create virtual reality (VR) environments for studying synchrony in human body movements and their prosocial effects. Previous studies have shown the positive effects of synchrony, but more controlled and ecologically valid paradigms are needed to explore these effects deeper and translate them to the therapeutic domain. A total of 82 healthy subjects participated in this study. They performed simple periodic hand movements in a virtual environment with a virtual character (VC) mimicking them. We used inverse kinematics (IKs) to create character movements. The VCs mimic the participants after a short delay in the synchronous group and after a great delay in the nonsynchronous group. The subjective feeling of synchrony and social closeness was measured using a set of rating questionnaires. The participants in the synchronous group reported more synchrony than the nonsynchronous group. The degree of social closeness between the two groups was not significantly different; however, there was a significant positive correlation between the reported degree of synchrony and social closeness within each group. Using a simple VR environment in which body movements are simulated by IKs can engender the feeling of synchrony and exert its prosocial effects.

CharacterMixer: Rig‐Aware Interpolation of 3D Characters

AbstractWe present CharacterMixer, a system for blending two rigged 3D characters with different mesh and skeleton topologies while maintaining a rig throughout interpolation. CharacterMixer also enables interpolation during motion for such characters, a novel feature. Interpolation is an important shape editing operation, but prior methods have limitations when applied to rigged characters: they either ignore the rig (making interpolated characters no longer posable) or use a fixed rig and mesh topology. To handle different mesh topologies, CharacterMixer uses a signed distance field (SDF) representation of character shapes, with one SDF per bone. To handle different skeleton topologies, it computes a hierarchical correspondence between source and target character skeletons and interpolates the SDFs of corresponding bones. This correspondence also allows the creation of a single “unified skeleton” for posing and animating interpolated characters. We show that CharacterMixer produces qualitatively better interpolation results than two state‐of‐the‐art methods while preserving a rig throughout interpolation. Project page: https://seanxzhan.github.io/projects/CharacterMixer.

Genre Features of Professional Screenplays in Russia in 1910s: Theory and Practice

The article explores the genre dominants of Silver Age screenplays. Theoretical concepts of film dramaturgy are applied to the texts of A. A. Khanzhonkov’s “From the World of Mystery” (1915) and A. S. Voznesensky’s “God” (1918). The scientific novelty of the study lies in the comprehensive analysis of these screenplay texts for the first time. The relevance is justified by contemporary philology’s interest in the intermedial aspect of literature. The screenplays exhibit an orientation towards literary models: a wide range of linguistic devices (metaphors, similes, inversions), complex composition, psychological depth, and more. Cinematic expressiveness is realized through a system of modalities (real time, memories, dreams, imagination, altered consciousness, etc.), description of character movements, and “visual sound.” The study suggests that the genre of screenwriting in silent cinema fundamentally differs from subsequent eras and tends towards the epic rather than the dramatic genre. Discrepancies between directorial and literary scripts occurred early in the genre’s formation. A comprehensive examination of original realized screenplays could be key to understanding the reasons for the unsatisfactory results of writer-filmmaker interactions.

Yuriko Doi’s Teaching and Transmission of Noh and Kyōgen in San Francisco

&lt;p&gt;Yuriko Doi founded the Theatre of Yugen in San Francisco and taught American students noh and kyōgen for more than thirty years. Noh theatre, in living practice in Japan for more than six hundred years, incorporates music, dance, acting, and singing. While noh is serious and sombre, kyōgen is a comedic form traditionally performed within or between noh plays. Starting in the late 1970s, Doi’s Theatre of Yugen performed new works inspired and informed by noh as well as kyōgen in English around the US and also in Japan. Noh training ideally begins in childhood as one-on-one study with a teacher and continues into adulthood. The transmission of noh is considered to be from body (teacher) to body (student) without verbal explication. To teach students in an ensemble theatre company in California, Doi adapted aspects of the transmission process as well as aspects of the form. Doi taught the exterior qualities of movement and vocal technique and, at the same time, tried to instill a sense of noh’s interior qualities, which include time, aesthetic intensity, and art practice as a life path. While teaching noh and kyōgen, Doi wants her students to draw from all of their training and influences. She explains that trying to hide other performance traditions held in the body, such as Western acting technique, will deflate the energy of a performance. She argues that if an actor can develop a complex sense of noh they can integrate it with all of the other knowledge structures in the body, which will lead to a masterful performance. Based on a series of interviews with Doi, the treatises of noh founder Zeami Motokiyo, and recent scholarship on noh, this essay examines the practice and transmission of noh and how the art is continued and revised through Doi’s work.&lt;/p&gt;

Physical education of students in the conditions of distance education

The article shows the importance of the role of motor activity in human life. The specially organized motor and physical activity of the student is distinguished, and the importance of vocational and applied physical training and general special physical training of the student for a person is proven. To overcome adaptation and transfer the whole organism to a higher level of functioning, movement qualities of different scales of influence are grouped. Ways to create effective conditions are shown for teaching the rational technique of sports movements. The purpose, task, organization, and stages of the process of physical education in higher education institutions in distance form are disclosed. The most effective methods and techniques in the conditions of distance learning, which change the attitude of students toward their health care, are analyzed. An experimental study of the analysis of the daily motor activity of students of higher education in the conditions of distance learning was carried out. Recommendations for overcoming the negative manifestations of distance learning have been developed and the most significant ways of reducing a sedentary lifestyle and maintaining an active physical form have been highlighted.