Learned Behavior

2016 ◽  
pp. 94-123 ◽  
Author(s):  
Jacquelyne Forgette ◽  
Michael Katchabaw
Keyword(s):  
Reinforcement Learning ◽  
Virtual Environments ◽  
Virtual Environment ◽  
Virtual World ◽  
Learning System ◽  
Experimental Results ◽  
Virtual Characters ◽  
Learned Behavior ◽  
The World ◽  
Over Time

A key challenge in programming virtual environments is to produce virtual characters that are autonomous and capable of action selections that appear believable. In this chapter, motivations are used as a basis for learning using reinforcements. With motives driving the decisions of characters, their actions will appear less structured and repetitious, and more human in nature. This will also allow developers to easily create virtual characters with specific motivations, based mostly on their narrative purposes or roles in the virtual world. With minimum and maximum desirable motive values, the characters use reinforcement learning to drive action selection to maximize their rewards across all motives. Experimental results show that a character can learn to satisfy as many as four motives, even with significantly delayed rewards, and motive changes that are caused by other characters in the world. While the actions tested are simple in nature, they show the potential of a more complicated motivation driven reinforcement learning system. The developer need only define a character's motivations, and the character will learn to act realistically over time in the virtual environment.

Designing A Successful HMD-Based Experience

1999 ◽  
Vol 8 (4) ◽  
pp. 469-473 ◽  
Author(s):  
Jeffrey S. Pierce ◽  
Randy Pausch ◽  
Christopher B. Sturgill ◽  
Kevin D. Christiansen
Keyword(s):  
Virtual Environments ◽  
Virtual Environment ◽  
Virtual World ◽  
Tea Party ◽  
Virtual Characters ◽  
Virtual Objects ◽  
Head Mounted Display ◽  
Virtual Experience

For entertainment applications, a successful virtual experience based on a head-mounted display (HMD) needs to overcome some or all of the following problems: entering a virtual world is a jarring experience, people do not naturally turn their heads or talk to each other while wearing an HMD, putting on the equipment is hard, and people do not realize when the experience is over. In the Electric Garden at SIGGRAPH 97, we presented the Mad Hatter's Tea Party, a shared virtual environment experienced by more than 1,500 SIGGRAPH attendees. We addressed these HMD-related problems with a combination of back story, see-through HMDs, virtual characters, continuity of real and virtual objects, and the layout of the physical and virtual environments.

A Transparent and Decentralized Model of Perception and Action for Intelligent Virtual Agents

2014 ◽  
Vol 23 (04) ◽  
pp. 1460020 ◽  
Author(s):  
George Anastassakis ◽  
Themis Panayiotopoulos
Keyword(s):  
Knowledge Representation ◽  
Virtual Environment ◽  
Virtual World ◽  
Perception And Action ◽  
Virtual Agents ◽  
Virtual Agent ◽  
Complex Interactions ◽  
Intelligent Virtual Agents ◽  
Decentralized Model ◽  
Over Time

Intelligent virtual agent behaviour is a crucial element of any virtual environment application as it essentially brings the environment to life, introduces believability and realism and enables complex interactions and evolution over time. However, the development of mechanisms for virtual agent perception and action is neither a trivial nor a straight-forward task. In this paper we present a model of perception and action for intelligent virtual agents that meets specific requirements and can as such be systematically implemented, can seamlessly and transparently integrate with knowledge representation and intelligent reasoning mechanisms, is highly independent of virtual world implementation specifics, and enables virtual agent portability and reuse.

A New Partitioning Method Based on AOI Model Matching in CVE Systems

2012 ◽  
Vol 241-244 ◽  
pp. 3116-3120
Author(s):  
Xiao Mei Hu ◽  
Biao Wang
Keyword(s):  
Virtual Environment ◽  
Virtual World ◽  
Experimental Results ◽  
Model Matching ◽  
Collaborative Virtual Environment ◽  
Area Of Interest ◽  
Key Issues ◽  
Partitioning Problem ◽  
Server Architecture

Collaborative Virtual Environment (CVE) system supports a large number of users to explore a virtual world and interact with each other through networks, so one of the key issues in the design of scalable CVE systems is the partitioning problem. Existing partitioning algorithms in CVE systems based on multiple-server architecture, in our opinion, hardly consider the communication character of virtual environment. In this paper, we propose a new partitioning method based on area of interest (AOI) model matching to improve the quality of partitioning. The experimental results show preliminarily that our partitioning approach based on AOI model matching does decrease the traffic among the servers in the system and improve the partitioning performance.

Virtual Worlds

2017 ◽  
pp. 549-568
Author(s):  
Michelangelo Tricarico
Keyword(s):  
Virtual Environments ◽  
Virtual Environment ◽  
Virtual Worlds ◽  
Virtual World ◽  
Learning Activities ◽  
Specific Field ◽  
Early School ◽  
Virtual Reconstruction ◽  
3D Virtual Environment ◽  
Master Builder

This chapter discusses the author's experience in virtual environments, with particular reference to virtual reconstruction. The events are narrated from the perspective of a student who at first developed his skills in this specific field at school, and then became competent and passionate enough to teach what he had learned in the course of time. He describes his experience from early school projects to the personal ones; from his award as a “Master Builder” to his early teaching lessons. Other learning activities that can be carried out in a virtual world are also illustrated, with particular reference to “coding”, which appears to be of great interest to the author. The main objective of this paper is to highlight the potential of a 3D virtual environment for the reconstruction of monuments, i.e., the author's area of expertise. It also provides a description of other activities that can be performed in a virtual environment, while illustrating the most common issues that can be experienced and suggesting how to solve them.

The Quality of Service Issue in Virtual Environments

2010 ◽  
pp. 1333-1340 ◽  
Author(s):  
Pedro Morillo ◽  
Juan Manuel Orduña ◽  
Marcos Fernandez
Keyword(s):  
Virtual Environments ◽  
Virtual Environment ◽  
Virtual World ◽  
Collaborative Design ◽  
Local Area Network ◽  
Local Area ◽  
Area Network ◽  
Simulation Techniques ◽  
Technological Means ◽  
Team Design

Networked virtual environments (NVEs) have become a major trend in distributed computing, mainly due to the enormous popularity of multi-player online games in the entertainment industry. Nowadays, NVE systems are considered as the supporting technology for many networked and virtual organizations (NVO) (Singhal & Zyda, 1999), especially to those classified within the field of computer supported cooperative work (CSCW), where networked computer can be seen as a standard to provide the technological means to support the team design (Ott & Nastansky, 1997). These highly interactive systems simulate a virtual world where multiple users share the same scenario. The system renders the images of the virtual world that each user would see if he was located at that point in the virtual environment. Each user is represented in the shared virtual environment by an entity called avatar, whose state is controlled by the user through the client computer. Hundreds and even thousands of client computers can be simultaneously connected to the NVE system through different networks, and even through the Internet. NVE systems are currently used in many different applications (Singhal & Zyda, 1999) such as civil and military distributed training (Miller & Thorpe, 1995), collaborative design (Salles, Galli, Almeida et al., 1997) and e-learning (Bouras, Fotakis, & Philopoulos, 1998). Nevertheless, the most extended example of NVE systems are commercial multi-player online game (MOG) environments. These systems use the same simulation techniques that NVE systems do, and they are predicted to make up over 25 percent of local area network (LAN) traffic by 2010 (McCreary & Claffy, 2000).

Presence within Virtual Environments as a Function of Visual Display Parameters

1996 ◽  
Vol 5 (3) ◽  
pp. 274-289 ◽  
Author(s):  
Claudia Hendrix ◽  
Woodrow Barfield
Keyword(s):  
Virtual Environments ◽  
Virtual Environment ◽  
Virtual World ◽  
Visual Image ◽  
Visual Display ◽  
Field Of View ◽  
Head Tracking ◽  
The Third ◽  
Sense Of Presence ◽  
Being There

This paper reports the results of three studies, each of which investigated the sense of presence within virtual environments as a function of visual display parameters. These factors included the presence or absence of head tracking, the presence or absence of stereoscopic cues, and the geometric field of view used to create the visual image projected on the visual display. In each study, subjects navigated a virtual environment and completed a questionnaire designed to ascertain the level of presence experienced by the participant within the virtual world. Specifically, two aspects of presence were evaluated: (1) the sense of “being there” and (2) the fidelity of the interaction between the virtual environment participant and the virtual world. Not surprisingly, the results of the first and second study indicated that the reported level of presence was significantly higher when head tracking and stereoscopic cues were provided. The results from the third study showed that the geometric field of view used to design the visual display highly influenced the reported level of presence, with more presence associated with a 50 and 90° geometric field of view when compared to a narrower 10° geometric field of view. The results also indicated a significant positive correlation between the reported level of presence and the fidelity of the interaction between the virtual environment participant and the virtual world. Finally, it was shown that the survey questions evaluating several aspects of presence produced reliable responses across questions and studies, indicating that the questionnaire is a useful tool when evaluating presence in virtual environments.

The Sense of Presence within Auditory Virtual Environments

1996 ◽  
Vol 5 (3) ◽  
pp. 290-301 ◽  
Author(s):  
Claudia Hendrix ◽  
Woodrow Barfield
Keyword(s):  
Virtual Environments ◽  
Virtual Environment ◽  
Sound Source ◽  
Virtual World ◽  
Auditory Display ◽  
Auditory Cues ◽  
Navigation Task ◽  
Perceived Realism ◽  
Sense Of Presence ◽  
Survey Questions

Two studies were performed to investigate the sense of presence within stereoscopic virtual environments as a function of the addition or absence of auditory cues. The first study examined the presence or absence of spatialized sound, while the second study compared the use of nonspatialized sound to spatialized sound. Sixteen subjects were allowed to navigate freely throughout several virtual environments and for each virtual environment, their level of presence, the virtual world realism, and interactivity between the participant and virtual environment were evaluated using survey questions. The results indicated that the addition of spatialized sound significantly increased the sense of presence but not the realism of the virtual environment. Despite this outcome, the addition of a spatialized sound source significantly increased the realism with which the subjects interacted with the sound source, and significantly increased the sense that sounds emanated from specific locations within the virtual environment. The results suggest that, in the context of a navigation task, while presence in virtual environments can be improved by the addition of auditory cues, the perceived realism of a virtual environment may be influenced more by changes in the visual rather than auditory display media. Implications of these results for presence within auditory virtual environments are discussed.

CRYSTAL: Building Multicontext Virtual Environments

1997 ◽  
Vol 6 (1) ◽  
pp. 57-72 ◽  
Author(s):  
Jeffrey Tsao ◽  
Charles J. Lumsden
Keyword(s):  
Virtual Environments ◽  
Virtual Environment ◽  
Virtual World ◽  
General Purpose ◽  
High Demand ◽  
Functional Elements ◽  
Unique Context

Current virtual environment systems are, for the most part, dedicated to specific applications such as engineering or surgery. The CRYSTAL project applied the concept of crystals, or 3D “windows,” to segment the virtual world into independent volumes, which may interact with each other. The contents of individual crystals can be very different from crystal to crystal, so the resulting virtual environment (VE) is not restricted to any unique context, and it is suitable as a general-purpose workspace. Crystals are created and owned by independent programs called modules, which serve as functional elements of the VE. There are basic modules to provide common functions, such as navigation, wand control, and so on. Extra modules can be launched to add content and functionality to the VE, and the modules can also be terminated interactively. Unlike “pipelined” systems for VE design, CRYSTAL modules are designed to self-assemble and resolve any interface conflicts automatically. As a result, they do not place a high demand on user proficiency in customizing VEs for a variety of uses.

Modelling Stages of Behaviour in Social Virtual Communities

2009 ◽  
pp. 1147-1156
Author(s):  
Lynne D. Roberts ◽  
Leigh M. Smith ◽  
Clare M. Pollock
Keyword(s):  
Virtual Environments ◽  
Virtual Environment ◽  
Internet Use ◽  
Virtual Communities ◽  
Demographic Factors ◽  
The Internet ◽  
Generic Model ◽  
The Impact ◽  
Over Time

Once connected to the Internet, there is a myriad of virtual communities that an individual can connect to, interact within and become a member of. However, little is known about the processes individuals employ in identifying, selecting, and interacting within these virtual communities. How does an individual decide which type of virtual environment they will use? What are the stages that individuals go through in their use of virtual communities? Do the stages of use vary across types of virtual communities? In this article, we examine these questions, focusing on stages of use of individual virtual communities within the larger context of patterns of Internet use over time. First, we examine predictors of the type of virtual environments that an individual might use, highlighting the impact of demographic factors, personality, history, and location of Internet use. Then we draw on our own research to examine stages of use of two types of synchronous text-based virtual environments. Finally, we develop a generic model of stages of use of virtual environments.

An Effective Aggregation Method in Distributed Virtual Environments

2011 ◽  
Vol 187 ◽  
pp. 475-479
Author(s):  
Ji Ming Chen ◽  
Zhi Wen Zou ◽  
Jin Gui Pan ◽  
Yuan Hao Sun
Keyword(s):  
Virtual Environments ◽  
Virtual Environment ◽  
Experimental Results ◽  
Aggregation Method ◽  
Distributed Virtual Environments ◽  
System A ◽  
Distributed Virtual Environment ◽  
Bounding Volume ◽  
Aggregation Problem

The aggregation problem of the interest expressions is an important problem in distributed virtual environment (DVE). According to the characteristic of DVE system, a new aggregation method is proposed in this paper, which uses hierarchical bounding volume to aggregate threshold predicate and TAG-ID/MASK to aggregate equivalent predicate separately. Experimental results show that this method can effectively reduce storage of interest expressions and highly improve the system’s scalability.

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