GraSp: Combining Spatially‐aware Mobile Devices and a Display Wall for Graph Visualization and Interaction

Going beyond established desktop interfaces, researchers have begun re‐thinking visualization approaches to make use of alternative display environments and more natural interaction modalities. In this paper, we investigate how spatially‐aware mobile displays and a large display wall can be coupled to support graph visualization and interaction. For that purpose, we distribute typical visualization views of classic node‐link and matrix representations between displays. The focus of our work lies in novel interaction techniques that enable users to work with personal mobile devices in combination with the wall. We devised and implemented a comprehensive interaction repertoire that supports basic and advanced graph exploration and manipulation tasks, including selection, details‐on‐demand, focus transitions, interactive lenses, and data editing. A qualitative study has been conducted to identify strengths and weaknesses of our techniques. Feedback showed that combining mobile devices and a wall‐sized display is useful for diverse graph‐related tasks. We also gained valuable insights regarding the distribution of visualization views and interactive tools among the combined displays.     

Projector placement planning for high quality visualizations on real-world colored objects

Many visualization applications benefit from displaying content on real-world objects rather than on a traditional display (e.g., a monitor). This type of visualization display is achieved by projecting precisely controlled illumination from multiple projectors onto the real-world colored objects. For such a task, the placement of the projectors is critical in assuring that the desired visualization is possible. Using ad hoc projector placement may cause some appearances to suffer from color shifting due to insufficient projector light radiance being exposed onto the physical surface. This leads to an incorrect appearance and ultimately to a false and potentially misleading visualization. In this paper, we present a framework to discover the optimal position and orientation of the projectors for such projection-based visualization displays. An optimal projector placement should be able to achieve the desired visualization with minimal projector light radiance. When determining optimal projector placement, object visibility, surface reflectance properties, and projector-surface distance and orientation need to be considered. We first formalize a theory for appearance editing image formation and construct a constrained linear system of equations that express when a desired novel appearance or visualization is possible given a geometric and surface reflectance model of the physical surface. Then, we show how to apply this constrained system in an adaptive search to efficiently discover the optimal projector placement which achieves the desired appearance. Constraints can be imposed on the maximum radiance allowed by the projectors and the projectors' placement to support specific goals of various visualization applications. We perform several real-world and simulated appearance edits and visualizations to demonstrate the improvement obtained by our discovered projector placement over ad hoc projector placement.     

Visualization of Simulated Urban Spaces: Inferring Parameterized Generation of Streets, Parcels, and Aerial Imagery

Urban simulation models and their visualization are used to help regional planning agencies evaluate alternative transportation investments, land use regulations, and environmental protection policies. Typical urban simulations provide spatially distributed data about number of inhabitants, land prices, traffic, and other variables. In this article, we build on a synergy of urban simulation, urban visualization, and computer graphics to automatically infer an urban layout for any time step of the simulation sequence. In addition to standard visualization tools, our method gathers data of the original street network, parcels, and aerial imagery and uses the available simulation results to infer changes to the original urban layout and produce a new and plausible layout for the simulation results. In contrast with previous work, our approach automatically updates the layout based on changes in the simulation data and thus can scale to a large simulation over many years. The method in this article offers a substantial step forward in building integrated visualization and behavioral simulation systems for use in community visioning, planning, and policy analysis. We demonstrate our method on several real cases using a 200 GB database for a 16,300 km2 area surrounding Seattle, Washington.     

High-resolution multiprojector display walls

Meeting the demands of the current tera-scale visualization community requires the use of large- and small-scale tiled displays. The Lawrence Livermore National Laboratory (LLNL) efforts in this area have led to the creation of one of the largest interactive tiled displays built to date, and a number of new efforts for “personal” tiled displays. Visualization hardware and software now being built will display up to 15 times the number of pixels in a typical desktop display. We outline the system implemented at LLNL for the creation and support of large, tiled, multi-pipe graphics displays. The system builds on a simple, portable, parallel API for tiling OpenGL commands in parallel to multiple contexts on a set of X servers. This API has allowed us to retrofit existing visualization and analysis codes to support these displays with very little effort. While this work represents a first step toward the ultimate goal of scalable visualization in individual office spaces, the result has been the creation of useful new visualization workspaces and tools for our users     

A Prototype of a Cooperative Visualization Workplace for the Aerodynamicist

Several feasibility studies for cooperative visualization were performed based on an existing modular visualization system. Two different architectures for the implementation of a cooperative system were identified, implemented and tested. One architectural model, the broadcast model, assumes either one single visualization system running on a central facility driving multiple displays or in case of cooperative work it assumes that each visualization module drives multiple displays. The second model, the synchronized visualization systems, features distributed visualization tools with synchronization mechanisms. The synchronization ensures that all partners create identical images from identical data. This model requires special control features to avoid conflicts created by user-interaction. Both architectures are complete by adding bi-directional video connection and audio communication over the network plus offering remote cursor functionality. Two prototype implementations were produced to compare the two architectures and to evaluate the feasibility of cooperative visualization on existing hardware. Because of the poor access to wide-area networks, the prototypes were tested in a local area network. Visualization protocols, data communication, video and audio ran on a standard Ethernet based on TCP/IP communications. The tests were done using typical data from aerodynamics or numerical flow simulations. In spite of the limits due to low network bandwidth and slow performance of some hardware components the second architecture using the synchronized systems seems to be useful and feasible even under today's circumstances. There are no additional features identified which would be needed to run the cooperative visualization on a wide area network but a higher network throughput would be required.     

Abstractive Representation and Exploration of Hierarchically Clustered Diffusion Tensor Fiber Tracts

Diffusion tensor imaging (DTI) has been used to generate fibrous structures in both brain white matter and muscles. Fiber clustering groups the DTI fibers into spatially and anatomically related tracts. As an increasing number of fiber clustering methods have been recently developed, it is important to display, compare, and explore the clustering results efficiently and effectively. In this paper, we present an anatomical visualization technique that reduces the geometric complexity of the fiber tracts and emphasizes the high‐level structures. Beginning with a volumetric diffusion tensor image, we first construct a hierarchical clustering representation of the fiber bundles. These bundles are then reformulated into a 3D multi‐valued volume data. We then build a set of geometric hulls and principal fibers to approximate the shape and orientation of each fiber bundle. By simultaneously visualizing the geometric hulls, individual fibers, and other data sets such as fractional anisotropy, the overall shape of the fiber tracts are highlighted, while preserving the fibrous details. A rater with expert knowledge of white matter structure has evaluated the resulting interactive illustration and confirmed the improvement over straightforward DTI fiber tract visualization.     

分子结构网络三维可视化系统的设计与实现

生物学数据的复杂性导致针对生物信息的可视化研究的不断深入,而网络是新兴的可视化工作的媒介,因此针对异地生物学数据设计网络三维可视化系统十分必要.该文研究网络环境下如何异地调用原始数据以及可视化工具,制定分子结构网络三维可视化系统的设计方案,实现网络环境下的分子结构可视化模型.该可视化系统在客户端仅仅需要一个标准浏览器而非胖客户端,使用户能方便地使用个人电脑远程浏览蛋白质分子结构图.通过不同原子个数的蛋白质分子在不同显示模式下的性能测试,表明了该系统的可行性.该系统有助于可视化地分析和利用生物学数据.     

电磁场与力场耦合仿真系统的可视化技术

科学计算可视化把由数值计算获得的大量数据以图像的方式表示出来，使抽象的数据内容及相互关系变得形象直观。OpenGL是一个功能强大的图形库，支持可视化实现的语言，在可视化的研究和开发中得到广泛的应用。该文以一个科学计算可视化软件一一电磁场与力场的耦合仿真系统为例，首先描述了整个系统的总体框架，然后着重介绍了OpenGL在其可视化开发过程中的应用，详细阐述了可视化仿真部分用到的三维实体建模、交互操作、字符显示、动画及双视口等关键技术。     

An empirical evaluation of four data visualization techniques for displaying short news text similarities

An experiment was conducted comparing user performance on four data visualization techniques—an unstructured display condition consisting of a random one-dimensional (1D) list and three proximity-based representations including a 1D list ranked by a greedy nearest-neighbor algorithm and two 2D spatial visualizations using the ISOMAP layout algorithm and multidimensional scaling (MDS). Eighty-one participants completed an information retrieval task where the visualization techniques were used to display a corpus consisting of 50 short news texts. Human pairwise similarity judgments for this corpus were used to create the three proximity-based displays. Results demonstrated an advantage in accuracy, the number of documents accessed, and, to a lesser extent, subjective confidence in these displays over the Random List condition and in the 2D over the 1D displays. Similar, but smaller, advantages were observed in the MDS display over ISOMAP however none of these pairwise comparisons were statistically significant. A sequential analysis of participant actions in terms of the proximity of document representations accessed provided some explanation for variations in performance between the displays as well as indicating strategic differences in interactions particularly between visualizations of different dimensionality.     

VCMM: A visual tool for continuum molecular modeling

This paper describes the design and function of a visualization tool, VCMM, for visualizing and analyzing data, and interfacing solvers for generic continuum molecular modeling. In particular, an emphasis of the program is to treat the data set based on unstructured mesh as used in finite/boundary element simulations, which largely enhances the capabilities of current visualization tools in this area that only support structured mesh. VCMM is segmented into molecular, meshing and numerical modules. The capabilities of molecular module include molecular visualization and force field assignment. Meshing module contains mesh generation, analysis and visualization tools. Numerical module currently provides a few finite/boundary element solvers of continuum molecular modeling, and contains several common visualization tools for the numerical result such as line and plane interpolations, surface probing, volume rendering and stream rendering. Three modules can exchange data with each other and carry out a complete process of modeling. Interfaces are also designed in order to facilitate usage of other mesh generation tools and numerical solvers. We develop a technique to accelerate data retrieval and have combined many graphical techniques in visualization. VCMM is highly extensible, and users can obtain more powerful functions by introducing relevant plug-ins. VCMM can also be useful in other fields such as computational quantum chemistry, image processing, and material science.     

An Evaluation of Glyph Perception for Real Symmetric Traceless Tensor Properties

A perceptual study of four tensor glyphs for symmetric, real, traceless tensors was performed. Each glyph encodes three properties of the system: Orientation, uniaxiality (alignment along the direction of orientation), and biaxiality (alignment along a vector orthogonal to the orientation). Thirty users over two studies were asked to identify these three properties for each glyph type under a variety of permutations in order to evaluate the effectiveness of visually communicating the properties; response time was also measured. We discuss the significant differences found between the methods as guidance to the use of these glyphs for traceless tensor visualization.     

Visualization of Biomolecular Structures: State of the Art Revisited

Structural properties of molecules are of primary concern in many fields. This report provides a comprehensive overview on techniques that have been developed in the fields of molecular graphics and visualization with a focus on applications in structural biology. The field heavily relies on computerized geometric and visual representations of three‐dimensional, complex, large and time‐varying molecular structures. The report presents a taxonomy that demonstrates which areas of molecular visualization have already been extensively investigated and where the field is currently heading. It discusses visualizations for molecular structures, strategies for efficient display regarding image quality and frame rate, covers different aspects of level of detail and reviews visualizations illustrating the dynamic aspects of molecular simulation data. The survey concludes with an outlook on promising and important research topics to foster further success in the development of tools that help to reveal molecular secrets.     

开滦集团全息数字化矿山管理平台的研究与设计

全息数字化矿山管理平台依托3D-GIS技术和虚拟仿真技术,通过构建一体化的三维可视化平台,将矿山地形地貌、地表设施、井巷工程、矿体围岩等客观空间构造,在平台系统中真实再现,充分利用现代空间分析、数据采矿、知识挖掘、虚拟现实、可视化、网络、多媒体和科学计算技术,为矿产资源评估、矿山规划、开拓设计、生产安全和决策管理进行模拟、仿真和过程分析提供新的技术平台和强大工具。     

Visualizing parallel programs and performance

Performance visualization uses graphical display techniques to analyze performance data and improve understanding of complex performance phenomena. Current parallel performance visualizations are predominantly two-dimensional. A primary goal of our work is to develop new methods for rapidly prototyping multidimensional performance visualizations. By applying the tools of scientific visualization, we can prototype these next-generation displays for performance visualization-if not implement them as end user tools-using existing software products and graphical techniques that physicists, oceanographers, and meteorologists have used for several years     

Fidelity in visualizing large-scale simulations

Computer simulations are powerful tools frequently used today in many important applications, for example to build safer buildings, to crash-test an automobile before it is built, to stabilize the Pisa tower, to design artificial joints that are comfortable and durable, or to investigate what-if scenarios to avoid and best recover from natural or man-made disasters. The simulation codes have reached a very high-level of sophistication and, by running on powerful computing machinery, can accurately track with infinitesimal time steps dozens of physical properties of millions of interacting elements under extreme conditions. In order to take fully advantage of the bounty of information concealed in the data produced, visualization is a uniquely powerful tool since it caters to the sense that provides our highest bandwidth connection to the surrounding world.Unfortunately, simulation results are usually examined with graphics and visualization tools that are one or several steps behind the state-of-the-art. We describe our efforts of producing high-fidelity visualizations of the results of large-scale simulations using the latest commercial rendering and animation systems. To this effect we built a scalable and reusable link between the software worlds of animation and simulation. Our system also offers a set of tools that allow integrating the results of the simulation in the surrounding scene, of great importance when the intended audience extends beyond the researchers that designed the simulation. We built our system as part of the efforts of a larger, interdisciplinary team to produce a high-quality, physically accurate visualization of the September 11 attack on the Pentagon.     

Head Orientation Prediction: Delta Quaternions Versus Quaternions

Display lag in simulation environments with helmet-mounted displays causes a loss of immersion that degrades the value of virtual/augmented reality training simulators. Simulators use predictive tracking to compensate for display lag, preparing display updates based on the anticipated head motion. This paper proposes a new method for predicting head orientation using a delta quaternion (DQ)-based extended Kalman filter (EKF) and compares the performance to a quaternion EKF. The proposed framework operates on the change in quaternion between consecutive data frames (the DQ), which avoids the heavy computational burden of the quaternion motion equation. Head velocity is estimated from the DQ by an EKF and then used to predict future head orientation. We have tested the new framework with captured head motion data and compared it with the computationally expensive quaternion filter. Experimental results indicate that the proposed DQ method provides the accuracy of the quaternion method without the heavy computational burden.     

The multimod application framework: a rapid application development tool for computer aided medicine

This paper describes a new application framework (OpenMAF) for rapid development of multimodal applications in computer-aided medicine. MAF applications are multimodal in data, in representation, and in interaction. The framework supports almost any type of biomedical data, including DICOM datasets, motion-capture recordings, or data from computer simulations (e.g. finite element modeling). The interactive visualization approach (multimodal display) helps the user interpret complex datasets, providing multiple representations of the same data. In addition, the framework allows multimodal interaction by supporting the simultaneous use of different input-output devices like 3D trackers, stereoscopic displays, haptics hardware and speech recognition/synthesis systems. The Framework has been designed to run smoothly even on limited power computers, but it can take advantage of all hardware capabilities. The Framework is based on a collection of portable libraries and it can be compiled on any platform that supports OpenGL, including Windows, MacOS X and any flavor of Unix/linux.     

多机制优化的模拟试验台数据流实时迁移研究

航空发动机高空模拟试验作为检验航空发动机性能的重要手段,其试验流程中采集的各传感器测点数据极为重要与珍贵。为了使数据信息的展示更为直观并且更深入挖掘数据潜在的价值,提出基于多框架集成的航空发动机高空模拟试验台数据流实时迁移及可视化技术。首先,利用MyBatis-Plus自动视图层构建可视化技术将存储于底层历史数据库中的信息直观地展示于Vue框架的浏览器端表结构空间中,方便试验员查看分析;然后利用基于GateWay限流机制的JDBC接口融合全量/增量和基于负载均衡机制的MyBatis框架融合多线程并行传输流的数据流迁移技术,将历史数据库中可供后续算法分析利用的重要数据信息同步至本地数据库中;最后,利用Vue框架的数据流前端监控界面,验证数据可视化展示的直观性、完整性、有效性和数据流同步的实时性。     

Visual Analysis of protein‐ligand interactions

The analysis of protein‐ligand interactions is complex because of the many factors at play. Most current methods for visual analysis provide this information in the form of simple 2D plots, which, besides being quite space hungry, often encode a low number of different properties. In this paper we present a system for compact 2D visualization of molecular simulations. It purposely omits most spatial information and presents physical information associated to single molecular components and their pairwise interactions through a set of 2D InfoVis tools with coordinated views, suitable interaction, and focus+context techniques to analyze large amounts of data. The system provides a wide range of motifs for elements such as protein secondary structures or hydrogen bond networks, and a set of tools for their interactive inspection, both for a single simulation and for comparing two different simulations. As a result, the analysis of protein‐ligand interactions of Molecular Simulation trajectories is greatly facilitated.