5903660
Stylized rendering of 3D scanned real world environments
This paper presents an interactive non-photorealistic rendering (NPR) system that stylizes and renders outdoor scenes captured by 3D laser scanning. In order to deal with the large size, complexity and inherent incompleteness of data obtained from outdoor scans, our system represents outdoor scenes using points instead of traditional polygons. Algorithms are then developed to extract, stylize and render features from this point representation. In addition to conveying various NPR styles, our system also promises consistency in animation by maintaining stroke coherence and density. We achieve NPR of large data at interactive rates by designing novel data structures and algorithms as well as leveraging new features of commodity graphics hardware.
10910603
Hybrid Forward Resampling and Volume Rendering
The transforming and rendering of discrete objects, such as traditional images (with or without depths) and volumes, can be considered as resampling problem – objects are reconstructed, transformed, filtered, and finally sampled on the screen grids. In resampling practices, discrete samples (pixels, voxels) can be considered either as infinitesimal sample points (simply called points) or samples of a certain size (splats). Resampling can also be done either forwards or backwards in either the source domain or the target domain. In this paper, we present a framework that features hybrid forward resampling for discrete rendering. Specifically, we apply this framework to enhance volumetric splatting. In this approach, minified voxels are taken simply as points filtered in screen space; while magnified voxels are taken as spherical splats. In addition, we develop two techniques for performing accurate and efficient perspective splatting. The first one is to efficiently compute the 2D elliptical geometry of perspectively projected splats; the second one is to achieve accurate perspective reconstruction filter. The results of our experiments demonstrate both the effectiveness of antialiasing and the efficiency of rendering using this
9140729
INSPIRE: an interactive image assisted non-photorealistic rendering system
We present a GPU supported interactive non-photorealistic rendering system, INSPIRE, which performs feature extraction in both image space, on intermediately rendered images, and object space, on models of various representations, e.g., point, polygon, or hybrid models, without needing connectivity information. INSPIRE obtains interactive NPR rendering with most styles of existing NPR systems, but offers more flexibility on model representations and compromises little on rendering speed.
10142893
PointWorks: Abstraction and Rendering of Sparsely Scanned Outdoor Environments
This paper describes a system, dubbed PointWorks, for rendering three-dimensionally digitized outdoor environments in non-photorealistic rendering styles. The challenge in rendering scanned outdoor environments is accommodating their inaccuracy, incompleteness, and large size to deliver a smooth animation without suggesting the underlying data deficiency. The key method discussed in this paper is employing artistic drawing techniques to illustrate features of varying importance and accuracy. We employ a point-based representation of the scanned environment and operate directly on point-based models for abstraction and rendering. We develop a framework for producing mainly two artistic styles: painterly and profile lines. Strategies have also been employed to leverage modern graphics hardware for achieving interactive rendering of large scenes.
9774737
A framework for modeling agent-oriented software
With the increasing importance of complex software systems in the software industry, the need for using agent technologies to develop large-scale commercial and industrial software systems is growing rapidly. Such systems are complex, and there is a pressing need for system modeling techniques to support reliable, maintainable and extensible design. G-nets are a type of Petri net defined to support the modeling of a system as a set of independent and loosely-coupled modules. In this paper, we first introduce an extension of G-nets - the agent-based G-net - as a generic model for agent design. Then, to progress from an agent-based design model to an agent-oriented model, new mechanisms to support inheritance modeling are introduced. To illustrate our formal modeling technique for multi-agent systems, an example of an agent family in electronic commerce is provided.
15979413
Consumers' Privacy Concerns toward Using Location-Based Services: An Exploratory Framework and Research Proposal
Privacy concerns associated with the use of Location-Based Services (LBS) may ultimately prevent consumers from gaining the ‘anytime anywhere’ convenience. Through a psychological control lens, we examine whether individual difference variables such as locus of control (LOC) could have moderating effects on the relationship between privacy concern and three privacy assurance mechanisms in the LBS context. The paper develops a preliminary research model which conceptualizes the moderating effects of LOC by extending Xu and Teo (2004)’s research model. With an explicit focus on LOC, this study will not only add an important piece of information to our understanding of consumers’ reactions to LBS but also can help frame the ongoing policy and scholarly debate surrounding the relative effectiveness of technology, industry self-regulation and government legislation in ensuring consumers’ privacy. We believe that our findings will be able to offer practical implications for the various players in the LBS landscape: merchants, wireless service providers, wireless device manufacturer, privacy advocates and legislators.
22135026
A Security Based Model for Mobile Agent Software Systems
Security modeling for agents has been one of the most challenging issues in developing practical mobile agent software systems. In the past, researchers have developed mobile agent systems with emphasis either on protecting mobile agents from malicious hosts or protecting hosts from malicious agents. In this paper, we propose a security based mobile agent system architecture that provides a general solution to protecting both mobile agents and agent hosts in terms of agent communication and agent migration. We present a facilitator agent model that serves as a middleware for secure agent communication and agent migration. The facilitator agent model, as well as the mobile agent model, is based on agent-oriented G-nets — a high level Petri net formalism. To illustrate our formal modeling technique for mobile agent systems, we provide an example of agent migration to show how a design error can be detected.
4864247
Data processing and compact representation of measured isotropic spectral BRDF
This paper presents the methods for both data processing and compact representation of measured isotropic spectral BRDF. For the data processing, we develop a numerical method for filtering the noises, re-sampling the data from non-uniform sampling to uniform sampling, and interpolation. For the compact representation, we propose a method to represent the spectral BRDF in both the spectral and spatial domains. In spectral domain, for each pair of the incident and outgoing directions, we represent the spectral BRDF with Fourier coefficients. In spatial domain, for all the outgoing directions of a given incident direction, we represent the same-order Fourier coefficients either directly using a linear combination of spherical harmonics or a linear combination of spherical harmonics and a Gaussian, depending on their angular dependencies. Three Gaussian expressions are presented. Numerical studies are given for a measured isotropic spectral BRDF.
14915210
A Framework for Model-Based Design of Agent-Oriented Software
Agents are becoming one of the most important topics in distributed and autonomous decentralized systems, and there are increasing attempts to use agent technologies to develop large-scale commercial and industrial software systems. The complexity of such systems suggests a pressing need for system modeling techniques to support reliable, maintainable, and extensible design. G-nets are a type of Petri net defined to support system modeling in terms of a set of independent and loosely-coupled modules. In this paper, we customize the basic G-net model to define a so-called "agent-based G-net" that can serve as a generic model for agent design. Then, to progress from an agent-based design model to an agent-oriented model, new mechanisms to support inheritance modeling are introduced. To illustrate our formal modeling technique for multiagent systems, an example of an agent family in electronic commerce is provided. Finally, we demonstrate how we can use model checking to verify some key behavioral properties of our agent model. This is facilitated by the use of an existing Petri net tool.