Realistic Virtual Humans Research Articles

Micro and macro facial expressions by driven animations in realistic Virtual Humans

Computer Graphics (CG) advancements have allowed the creation of more realistic Virtual Humans (VH) through modern techniques for animating the VH body and face, thereby affecting perception. From traditional methods, including blend shapes, to driven animations using facial and body tracking, these advancements can potentially enhance the perception of comfort and realism in relation to VHs. Previously, Psychology studied facial movements in humans, with some works separating expressions into macro and micro expressions. Also, some previous CG studies have analyzed how macro and micro expressions are perceived, replicating psychology studies in VHs, encompassing studies with realistic and cartoon VHs, and exploring different VH technologies. However, instead of using facial tracking animation methods, these previous studies animated the VHs using blendshapes interpolation. To understand how the facial tracking technique alters the perception of VHs, this paper extends the study to macro and micro expressions, employing two datasets to transfer real facial expressions to VHs and analyze how their expressions are perceived. Our findings suggest that transferring facial expressions from real actors to VHs significantly diminishes the accuracy of emotion perception compared to VH facial animations created by artists.

Cognitive Model of Agent Exploration with Vision and Signage Understanding

AbstractSignage systems play an essential role in ensuring safe, stress‐free, and efficient navigation for the occupants of indoor spaces. Crowd simulations with sufficiently realistic virtual humans provide a convenient and cost‐effective approach to evaluating and optimizing signage systems. In this work, we develop an agent model which makes use of image processing on parametric saliency maps to visually identify signage and distractions in the agent's field of view. Information from identified signs is incorporated into a grid‐based representation of wayfinding familiarity, which is used to guide informed exploration of the agent's environment using a modified A* algorithm. In areas with low wayfinding familiarity, the agent follows a random exploration behaviour based on sampling a grid of previously observed locations for heuristic values based on space syntax isovist measures. The resulting agent design is evaluated in a variety of test environments and found to be able to reliably navigate towards a goal location using a combination of signage and random exploration.

Automatic estimation of parametric saliency maps (PSMs) for autonomous pedestrians

Modelling 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.This is an extended version of a short paper published in MIG 2021. The extension includes an optimization approach that fits the parameters of the proposed model to established saliency models such as SALICON using a much larger and more realistic urban test set.

Nonverbal communication in virtual reality: Nodding as a social signal in virtual interactions

Nonverbal communication is an important part of human communication, including head nodding, eye gaze, proximity and body orientation. Recent research has identified specific patterns of head nodding linked to conversation, namely mimicry of head movements at 600 ms delay and fast nodding when listening. In this paper, we implemented these head nodding behaviour rules in virtual humans, and we tested the impact of these behaviours, and whether they lead to increases in trust and liking towards the virtual humans. We use Virtual Reality technology to simulate a face-to-face conversation, as VR provides a high level of immersiveness and social presence, very similar to face-to-face interaction. We then conducted a study with human-subject participants, where the participants took part in conversations with two virtual humans and then rated the virtual character social characteristics, and completed an evaluation of their implicit trust in the virtual human. Results showed more liking for and more trust in the virtual human whose nodding behaviour was driven by realistic behaviour rules. This supports the psychological models of nodding and advances our ability to build realistic virtual humans.

Realistic Virtual Humans for Cultural Heritage Applications

Virtual Humans are becoming a commodity in computing technology and lately have been utilized in the context of interactive presentations in Virtual Cultural Heritage environments and exhibitions. To this end, this research work underlines the importance of aligning and fine-tuning Virtual Humans’ appearance to their roles and highlights the importance of affective components. Building realistic Virtual Humans was traditionally a great challenge requiring a professional motion capturing studio and heavy resources in 3D animation and design. In this paper, a workflow for their implementation is presented, based on current technological trends in wearable mocap systems and advancements in software technology for their implementation, animation, and visualization. The workflow starts from motion recording and segmentation to avatar implementation, retargeting, animation, lip synchronization, face morphing, and integration to a virtual or physical environment. The testing of the workflow occurs in a use case for the Mastic Museum of Chios and the implementation is validated both in a 3D virtual environment accessed through Virtual Reality and on-site at the museum through an Augmented Reality application. The findings, support the initial hypothesis through a formative evaluation, and lessons learned are transformed into a set of guidelines to support the replication of this work.

Operators’ accessibility studies for assembly and maintenance scenarios using virtual reality

The development of fusion plants is more and more challenging. Compared to previous fusion experimental devices, integration constraints, maintenance and safety requirements are key parameters in the ITER project. Components are designed in parallel and we must consider integration, assembly and maintenance issues, which might have a huge impact on the overall design. That also implies to consider the operator’s feedback to assess the feasibility of accessibility or maintenance processes.Virtual reality (VR) provides tools to optimize such integration. In 2010, the CEA IRFM decided to upgrade its design tools, by using VR during the life cycle (from design to operations) of a fusion component. The VR platform is intensively used in the design and assembly studies of WEST components. In particular, feasibility of the assembly scenario is assessed by the operators involving in the real assembly work.To study this aspect, the use of static manikins is quite frequent in the industry. However, more complex studies, like the feasibility of assembly and maintenance tasks in complex and very confined environments, require enhanced features such as dynamic and biomechanically realistic virtual humans. We also study the contribution of tactile feedback to improve physical presence and interaction in the virtual environment (VE), which is very important for the validation of a given task’s feasibility and the ergonomic evaluation of the posture and gesture of the operator. In particular, we show that adapted behavior in respect to physical elements of the VE can be obtained using a dynamic co-localized representation of the subject’s body and a pseudo-haptic tactile feedback.In this paper, we present integration studies involving operators and recent advances in the assessment of maintenance feasibility.

Creating Autonomous, Perceptive and Intelligent Virtual Humans in a Real-Time Virtual Environment

Creating realistic virtual humans has been a challenging objective in computer science research for some time. This paper describes an integrated framework for modeling virtual humans with a high level of autonomy. The framework seeks to reproduce human-like believable behavior and movement in virtual humans in a virtual environment. The framework includes a visual and auditory information perception module, a decision network based behavior decision module, and a hierarchical autonomous motion control module. These cooperate to model realistic autonomous individual behavior for virtual humans in real-time interactive virtual environments. The framework was tested in a simulated virtual environment system to demonstrate the ability of the framework to create autonomous, perceptive and intelligent virtual humans in real-time virtual environments.

An action selection process to simulate the human behavior in virtual humans with real personality

In this paper, we present an action selection mechanism to simulate the human behavior in realistic and believable virtual humans according to their personality and affective state taking into account their beliefs, desires, intentions, and the level of intensity of the events they perceive from their environment.

Parallelization issues of a code for physically-based simulation of fabrics

The simulation of fabrics, clothes, and flexible materials is an essential topic in computer animation of realistic virtual humans and dynamic sceneries. New emerging technologies, as interactive digital TV and multimedia products, make necessary the development of powerful tools to perform real-time simulations. Parallelism is one of such tools. When analyzing computationally fabric simulations we found these codes belonging to the complex class of irregular applications. Frequently this kind of codes includes reduction operations in their core, so that an important fraction of the computational time is spent on such operations. In fabric simulators these operations appear when evaluating forces, giving rise to the equation system to be solved. For this reason, this paper discusses only this phase of the simulation. This paper analyzes and evaluates different irregular reduction parallelization techniques on ccNUMA shared memory machines, applied to a real, physically-based, fabric simulator we have developed. Several issues are taken into account in order to achieve high code performance, as exploitation of data access locality and parallelism, as well as careful use of memory resources (memory overhead). In this paper we use the concept of data affinity to develop various efficient algorithms for reduction parallelization exploiting data locality.

Sharing attractions on the Net with VPark

We present a networked virtual environment (NVE) system and an attraction building system based on Windows NT that enables users to introduce their own scenario-based applications into a shared virtual environment. Our goal was to develop and integrate several modules into a system capable of animating realistic virtual humans in a real-time performance. This includes modeling and representing virtual humans with high realism and simulating human face and body movements in real time. Realism becomes quite important in NVEs, where the communication among participants is crucial for their sense of presence.

3D graphics define virtual humans on the web

It is now possible to explore 3D worlds on the Wold Wide Web (using a classical navigator) as easily as it is to view 2D pages. No longer restricted to powerful machines, 3D graphics provide a new interface for communication. The definition of realistic virtual humans in these worlds produces a more intuitive interface for novices. CHRISTIAN BABSKI and DANIEL THALMANN propose a set of tools for defining virtual humans and bringing them to life using a standard 3D language for the Web. Copyright © 2000 John Wiley & Sons, Ltd.

Real-time animation of realistic virtual humans

The authors have been working on simulating virtual humans for several years. Until recently, these constructs could not act in real time. Today, however, many applications need to simulate in real time virtual humans that look realistic. They have invested considerable effort in developing and integrating several modules into a system capable of animating humans in real-time situations. This includes interactive modules for building realistic individuals and a texture-fitting method suitable for all parts of the head and body. Animating the body, including the hands and their deformations, is the key aspect of the system; to their knowledge, no competing system integrates all these functions. They also included facial animation, as demonstrated below with virtual tennis players. They have developed a single system containing all the modules needed for simulating real-time virtual humans in distant virtual environments (VEs). The system lets one rapidly clone any individual and animate the clone in various contexts. People cannot mistake virtual humans for real ones, but they think them recognizable and realistic.