VRML Research Articles

A new dimension for assessing the quality of surgical repair of cleft deformities

Objective: To evaluate 3D nasolabial morphology, relative to contemporaneous non-cleft data, following primary reconstruction of unilateral cleft lip and palate (UCLP). Materials and methods: Prospective, cross-sectional, case-control study performed on two groups of children, 21 with surgically repaired UCLP and 73 controls were examined at 3 years using stereophotogrammetry. 3D co-ordinates of anthropometric landmarks were extracted from virtual reality modelling language images created by computerized stereophotogrammetry. To assess the reproducibility of landmarks digitization, a randomly selected 20 3D models were redigitized. Systematic and random errors were calculated according to Dahlbergh equation. Results: Landmarks digitization error was within 0.5 mm. Nasolabial appearance was improved following cleft repair but was significantly different from non-cleft children at the following areas: (1) asymmetry of the nose with display of the alar base on the affected side more laterally and inferiorly; (2) midface hypoplasia; (3) short upper lip on the cleft side; (4) asymmetry of the nostrils There was no statistical significant difference in columella width between the UCLP group and control group. Conclusions: 3D imaging is an emerging modality that is suitable for paediatric population. Geometric morphometrics is superior to traditional analysis of facial morphology. The soft tissue facial deformity in 3-year-old children with unilateral cleft lip and palate is closely related to the site of primary surgery.

Simulation of reinforcement-corrosion-induced crack propagation in concrete by acoustic emission technique and boundary element method analysis

Corrosion of reinforcement is one of the major causes of deterioration in reinforced concrete structures. Various crack patterns are nucleated around reinforcement in concrete due to expansion of corrosion products. Crack kinematics of locations, types, and orientations are quantitatively determined by the acoustic emission (AE) – simplified Green’s functions for moment tensor analysis (SiGMA) procedure in association with laboratory tests conducted on concrete specimens simulating corrosion-induced damage. These kinematic outcomes are obtained as three-dimensional (3-D) locations and vectors, and are thus visualized in 3-D by using virtual reality modeling language (VRML). Numerical analysis is conducted by the boundary element method (BEM) based on the concept of linear elastic fracture mechanics (LEFM) to clarify the mechanisms of corrosion-induced crack extension. Relationships between dimensionless stress intensity factors and cracking types are studied by BEM. Contributions of mode I and mode II failures are dependent on the cracking types. It is found that the process of crack propagation due to corrosion of reinforcement in concrete is mostly a mode I fracture with mixed-mode and, in a few cases, mode II fracture.Key words: acoustic emission, moment tensor, corrosion cracking, stress intensity factor.

IBEM analyses on half-cell potential measurement for NDE of rebar corrosion

Corrosion of Reinforcement (rebar) is nondestructively estimated by the half-cell potential measurement. As is the case with other nondestructive testings (NDT), understanding of the underlying principles should be clarified in order to obtain meaningful results. Therefore, the measurement of potentials in concrete is analytically investigated. The effect of internal defects on the potentials measured is clarified numerically by the boundary element method (BEM). Thus, a simplified inversion by BEM is applied to convert the potentials on concrete surface to those on rebars, taking into account the concrete resistivity. Because the potentials measured on concrete surface are so sensitive to moisture content, concrete resistivity and surface condition, an inverse procedure to convert the potentials on concrete surface into those on rebars is developed on the basis of BEM. It is found that ASTM criterion is practically applicable to estimate corrosion from the potential values converted. In experiments, an applicability of the procedure is examined by accelerated corrosion tests of reinforced concrete (RC) slabs. For practical use, the procedure is developed where results of IBEM are visualized by VRML (Virtual Reality modeling Language) in three-dimensional space.

A finite element method (FEM) – Fuzzy logic (Soft Computing) – virtual reality model approach in a coalface longwall mining simulation

The modelling of the behaviour of a longwall coal mining installation is not an easy task, particularly when we deal with a coal seam exceeding 4 m of thickness. The variables playing a role on the performance of the shearer and powered roof support are both difficult to define and quantify and technologies involved belong to several different scientific areas: geology, rock mechanics, stress-deformation calculations and hydraulics. State of the art modelling tools, fuzzy logic, neural networks and three-dimensional (3D) finite element calculations are employed in order to develop a computerized model that will allow predicting the response of the installation against changing operation conditions. This response is checked against extensive data obtained from deep measurement campaigns and finally shown to the system user through Virtual Reality Modelling Language (VRML) tools.

The use of virtual reality in visualizing land property

The paper discusses virtual reality as a visualization tool such that users could interact with a developed application medium, as if they are inside the virtual environment presenting the application. Virtual reality as a presentational medium offers different views of reality which real estate agents could use to visualize estate properties. In this paper the virtual application (prototype) was designed using ArcGIS 8.2, Internet Space Builder (ISB) and Image Editing software. Interviews and responses to questionnaires used as inputs to developing the application are highlighted. The developed application involving 3D virtual environment was achieved by exporting an extruded two and half dimensional (2½ D) cube-like shapes of cadastral parcel boundaries into Virtual Reality Modelling Language (VRML). The developed application was then tested. The intent of developing the 3D virtual application (prototype) is to help clients' of real estate agents to visualize properties in 3D when they visit the real estate agents.Journal of Science and Technology(Ghana) Vol. 27 (1) 2007: pp. 102-108

Application of the Virtual Reality Modeling Language for Design of Automated Workplaces

Application of the Virtual Reality Modeling Language for Design of Automated Workplaces

An animated depiction of major depression epidemiology

BackgroundEpidemiologic estimates are now available for a variety of parameters related to major depression epidemiology (incidence, prevalence, etc.). These estimates are potentially useful for policy and planning purposes, but it is first necessary that they be synthesized into a coherent picture of the epidemiology of the condition. Several attempts to do so have been made using mathematical modeling procedures. However, this information is not easy to communicate to users of epidemiological data (clinicians, administrators, policy makers).MethodsIn this study, up-to-date data on major depression epidemiology were integrated using a discrete event simulation model. The mathematical model was animated in Virtual Reality Modeling Language (VRML) to create a visual, rather than mathematical, depiction of the epidemiology.ResultsConsistent with existing literature, the model highlights potential advantages of population health strategies that emphasize access to effective long-term treatment. The paper contains a web-link to the animation.ConclusionVisual animation of epidemiological results may be an effective knowledge translation tool. In clinical practice, such animations could potentially assist with patient education and enhanced long-term compliance.

Visualising coastal seabed characteristics: Using VRML models to present three dimensional spacial data via the web

Geoscience Australia has produced free Web‐viewable 3D models of coastal data for sharing data and information with project partners and coastal zone stakeholders. The models integrate a range of spatial data (including DEMs, multibeam bathymetry, sediment samples, benthic habitats and satellite imagery) within an easy to use interface. The models use the open source and ISO standard Virtual Reality Modelling Language (VRML) file format. The model described in this paper is for the Keppel Bay and Fitzroy River area in Queensland, Australia. These 3D VRML models are a good method for integrating coastal data, for better interpretation, and are easily transferred to end users via the Web.

Location-aware visualization of VRML models in indoor location tracking system

For many applications particularly in navigation system, a three-dimensional representation improves the usability of information. This paper introduces 3D Graphical User Interface (GUI) of indoor location tracking system, 3D Navigation View. The application provides users a 3D visualization of the indoor environments they are exploring, synchronized with the physical world through spatial information obtained from indoor location tracking system. It adopts widely used Virtual Reality Modeling Language (VRML) to construct, represent, distribute and render 3D world of indoor environments over Internet. Java, an all-purpose programming language is integrated to comprehend spatial information received from indoor location tracking system. Both are connected through an interface called External Authoring Interface (EAI) provided by VRML. Via EAI, Java is given the authority to access and manipulate the 3D objects inside the 3D world that facilitates the indication of user`s position and viewpoint in the constructed virtual indoor environments periodically.

Creating and Displaying Virtual Silicate Structures Using Geographic Information Systems

This paper illustrates the capabilities of geographic information system (GIS) software to create and display silicate structures. These models require no knowledge of editing functionality within the GIS software. Instead, the required input is the coordinates of the individual atoms or tetrahedra constructed in a word processing or spreadsheet program. These coordinates are then imported into the GIS software, and can be used to display chain, ring, sheet, and framework structures. Links to silicate models exported from the GIS software in a virtual reality modeling language (VRML) format are provided. These models can be displayed using a web browser equipped with any freely available VRML plug-in.Creating GIS-based silicate structures is an alternative to other software packages such as CrystalMaker® and Xtaldraw® designed specifically to create and display atomic structures. Although these GIS-based methods do not have all of the functionality of custom applications, GIS is a pervasive and growing technology with numerous applications in earth sciences and many other disciplines. Instructors may consider using this GIS-based method to introduce geospatial concepts, illustrate the breadth of GIS applications, and to establish interactive links between mineralogy and other disciplines.

Towards building a photo-realistic virtual human face for craniomaxillofacial diagnosis and treatment planning

The aim of this investigation was to assess the feasibility of building a virtual human face digitally by superimposing a photo-realistic three-dimensional (3D) soft-tissue surface on bone in the correct relationship and evaluating the registration errors associated with this method. The 3D soft-tissue surface of the face was captured using a fast stereophotogrammetry method and the underlying bone was recorded using a 3D computed tomography (CT) scanner. Using the Procrustes registration method, the outer surface of the 3D CT scan and the photo-realistic soft-tissue surfaces were merged into a single Virtual Reality Modelling Language (VRML) file and displayed using a standard VRML viewer. Quantitative measurements of registration errors were calculated in the reconstructed human head models using the signed closest point distance from the photo-realistic skin surface to the transformed CT skin surface. The registration errors between most parts of the aligned surfaces were within ±1.5 mm. The errors were relatively large around the eyebrows, eyelids and cheeks. Simultaneous recording of the face and skull may reduce this error.

Development of 3-D viewer for indoor location tracking system using wireless sensor network

In this paper we present 3-D Navigation View, a three-dimensional visualization of indoor environment which serves as an intuitive and unified user interface for our developed indoor location tracking system via Virtual Reality Modeling Language (VRML) in web environment. The extracted user's spatial information from indoor location tracking system was further processed to facilitate the location indication in virtual 3-D indoor environment based on his location in physical world. External Authoring Interface (EAI) provided by VRML enables the integration of interactive 3-D graphics into web and direct communication with the encapsulated Java applet to update position and viewpoint of user periodically in 3-D indoor environment. As any web browser with VRML viewer plug-in is able to run the platform independent 3-D Navigation View, specialized and expensive hardware or software can be disregarded.

Development of a STEP-based Production Information System for Block Assembly Process

More effective production planning and scheduling in shipbuilding is needed to prepare the master data related to the products, the progress of work, and the production method. Therefore, it is most important to generate automatically the master data from a computer-aided design (CAD) model. However, production engineers manually read and analyze the assembly drawings with the detailed process of production, create, and input the master data. It is a time consuming job and also the data are neither clear nor accurate. In this study, we have developed a production information system using Standard for the Exchange of Product Model Data (STEP), which generates detailed production-oriented master data systematically and automatically from the CAD hull models considering work process. This production information includes many properties, such as assembly trees, working location, the working posture of setting and welding, material, detailed welding property, direction of stiffeners, plates and assemblies, specifications of parts and assemblies, curvature, turn-over, bevel of seams, slit and open, and throat thickness of welds. Secondly, three-dimensional geometric data (Virtual Reality Modeling Language, VRML) from subassemblies to grand assembly can be generated automatically according to the production process and method. We've tried to improve the quality of the production planning and scheduling with highly accurate detailed master data.

Usefulness of VRML building models in a direction finding context

This paper describes an experiment which aims to examine the effectiveness and efficiency of a Virtual Reality Modelling Language (VRML) building model compared with equivalent architectural plans, for direction finding purposes. The effectiveness and efficiency issues being primarily investigated were number of tasks completed overall and task completion times. The experiment involved a series of tasks where participants had to find a number of locations/objects in a building unknown to them at the outset of the experiment. Statistically significant results are presented for the benefit of the research community, law enforcement officers and fire fighters where it is clear that in this context, the VRML model led to better task completions than the equivalent architectural plans. Regarding the task completion times, no statistical significance was found. Given the current climate of security issues and terrorist threats, it is important that law enforcement officers have at their disposal the best information possible regarding the layout of a building, whilst keeping costs down. This also applies to fire fighters when rescuing victims. This experiment has shown that a VRML model leads to better task completions in direction finding.

Web-based virtual CNC machine modeling and operation

A CNC simulation system based on intemet for operation training of manufacturing facility and manufacturing process simulation is proposed.Firstly,the system framework and a rapid modeling method of CNC machine tool are studied under the virtual environment based on PolyTrans and CAD software.Then,a new method is proposed to enhance and expand the interactive ability of virtual reality modeling language(VRML) by attaining communication among VRML,JavaApplet, JavaScript and Html so as to realize the virtual operation for CNC machine tool.Moreover,the algorithm of material removed simulation based on VRML Z-map is presented.The advantages of this algorithm include less memory requirement and much higher computation.Lastly,the C'NC milling machine is taken as an illustrative example for the prototype development in order to validate the feasibility of the proposed approach.

Model of internal geometry of textile fabrics: Data structure and virtual reality implementation

The internal architecture of a textile affects its mechanical behaviour (deformability, draping, permeability etc.). It is also important for properties of the textile composites (stiffness, strength etc.). The internal geometry of a wide range of fabrics - 2D and 3D woven, two- and three-axial braided, knitted, multi-axial multi-ply stitched fabrics and laminates - for both relaxed and deformed states is explained. This article explains the format of the fabric internal geometry data and the algorithms of exporting the data to different modelling environments (e.g. finite element or computational fluid dynamics models). The transformation of the model into virtual reality (VR) world (VR Modelling Language) is described in detail. VR description of a textile at the micro level, based on mechanical models of the internal structure, complements the available VR representation of a textile on the macro level.

Alternativas de diseño: arquitectura para el ciberespacio como estrategia de enseñanza Caso Sede Virtual 3D Interactiva Multiusuario para el Taller Virtual de las Américas

Este artículo se orienta a describir productos del curso «Alternativas de Diseño 2005» que persigue preparar arquitectos del Departamento de Maestría de Computación en Arquitectura (LUZ-Maracaibo) aplicando una metodología basada en VRML y Java Script orientada a alcanzar una propuesta para el «Taller de Diseño Virtual Las Américas».

Visualizing processes on the web

In this paper, we describe 3WPS, a framework to build distributed systems that are able to monitor and interact with a process through a 3D interface that is accessible via the World Wide Web ( WWW). The 3WPS is easily configurable, easily adaptable to different processes with high reuse of its software components and its distributed architecture leverages on off-the-shelf components of the WWW infrastructure such as Java applets and Virtual Reality Modeling Language (VRML) browsers. We describe the characteristics of 3WPS framework by mainly focusing on the issue of programmability and by contextually providing an example tour of its usage.

VRML use for Iterative Usability Testing of user Interfaces: A Novel Continuum Robotic Limb Example

Our team has developed a teleoperated robotic arm based on the biological model of an octopus. This “OctArm” has several advantages over traditional robotic designs, including the ability to grasp fragile objects with soft compliance, distributed pressure and the ability to pick up large or irregularly shaped objects. The development of an operator interface using a Virtual Reality Modeling Language (VRML) simulation has been a major focus. The simulation is used for both portable usability testing and as a visual display aid during the operation of the arm. Usability tests have been completed in the laboratory and the interface was tested in the field during an event sponsored by the Alliance for Robot Assisted Crisis Assessment and Response (ARACAR). VRML has proved to be a very useful tool for the development of the operator interface, robot control strategies, and training regimes. The use of VRML as a usability tool will be demonstrated.

Three-dimensional rotational angiography guidance for aneurysm surgery

The aim of this study was to investigate the feasibility of integrating three-dimensional rotational angiography (3D-RA) data into a surgical navigation system and to assess its accuracy and potential clinical benefit. The study cohort consisted of 16 patients with 16 intracranial aneurysms who had been scheduled for routine or emergency surgery. Rotational angiography data were exported using a virtual reality modeling language file format and imported into the BrainLAB VectorVision2 image-guided surgery equipment. During 3D-RA the position of the head was measured using a special headframe. The authors also determined the accuracy of 3D-RA image guidance and the clinical benefit as judged by the surgeon, including, for example, early identification of branching vessels and the aneurysm. There was good correspondence between the 3D-RA-based navigation data and the intraoperative vascular anatomy in all cases, with a maximum error of 9 degrees of angulation and 9 degrees of rotation. In eight cases, the surgeon determined that the 3D-RA image guidance facilitated the surgical procedure by predicting the location of the aneurysm or the origin of a branching artery that had been covered by brain tissue and blood clots. The integration of 3D-RA into surgical navigation systems is feasible, but it currently requires a new perspective-registration technique. The intraoperative 3D view provides useful information about the vascular anatomy and may improve the quality of aneurysm surgery in selected cases.