Construction Of 3D Model Research Articles

Working in complex areas: New restoration workflow based on quality control, 2D and 3D restorations

When working in complex areas, the explorationist needs to construct 3D models and to check their coherency. Coherence can be analyzed on the current geometry but could also be quantified through restoration. To achieve this restoration, i.e. the search for an initial geometry with a realistic deformation pathway between the initial and the final geometries, appropriate tools are necessary. These include classical cross-section balancing, surface unfolding and volumetric restoration. In this paper, we will describe a workflow to do quantitative structural geology in complex areas. This includes the construction and quality control of the surfacic model, the line balancing, the cross-section, surface and multi-surface restoration and the volumic restoration. In addition to the quality control of the geometries, the restoration allows us to compute strain tensors. This can be done in the three types of restoration and visualized through ellipses and ellipsoids (resp. 2D and 3D) that represent the main strain or stress vectors. We shall discuss the relationship between these strain tensors and the expected fracture network, in density as in direction.

Constructing Web-Based Object-Oriented Design Support System for Collaborative Ship Modeling

Multidiscipline three-dimensional (3D) design tools are utilized by most advanced shipyards in the world to gain both competitive advantage and productivity. While deadlines become shorter and shorter, the complexity of modern commercial vessels increases steadily; therefore, it is imperative for the marine industry to integrate diverse engineering information systems. 3D models are repetitiously constructed mainly because specified requirements on different design stages are time-consuming. In order to supersede costly point-to-point integration or system-specific integration that have been used, much attention has been paid to develop the advanced and open platform to not only codevelop parts by designers at different geographical locations, coordinate dissimilar applications and application components, but facilitate connectivity and the overall communication process to provide the end user with integrated and consistent data. This paper describes the object-oriented data-sharing collaborative design support system (DSS). DSS is proposed to speed up the construction of 3D models by the Internet technologies to translate product data and further be capable of providing reasonable model configurations of XML descriptions and sharing Web Services on the Internet to comply with shipyards' specific strategies.

Construction of three-dimensional models of mechanical products from their orthographic views using computer vision

The construction of a three-dimensional (3D) model of objects is a key element of many interesting applications such as computer graphics and computer-aided design (CAD). Although many techniques for the construction of 3D models are available, these techniques are still the focus of attention from researchers in the computer vision community. In the current paper, a low-cost vision system has been employed to construct 3D models of small mechanical products using the image-based modelling technique and the basic principles of the orthographic views. The system has been calibrated to compensate for the variations in size of the captured images resulting from the difference in dimensions of the product to be reconstructed. The 3D models are constructed from two captured images, which represent two different views of the product. The constructed 3D model can be viewed through a developed software or exported to any CAD software, such as AutoCAD, for further editing. The mathematical model of the employed 3D construction technique is presented and the verification of the proposed system is introduced.

Linear and angular measurements of computer-generated models: Are they accurate, valid, and reliable?

Introduction: Traditional advanced imaging modalities such as CT and MRI are limited in their ability to perform accurate linear distance and angular measurements regardless of anatomical orientation. The construction of 3D models has been used to perform anthropometric analyses as well as in the reconstruction of rapid prototypes. We hypothesized that such measurements would be precise to within 2 mm or 2° of measurements performed with a coordinate measurement machine (CMM). We also hypothesized that there would be a high degree of interobserver reliability with these measurements.Materials and Methods: Multiple aluminum screws were implanted in various positions in three foam pelvises which were subsequently scanned by CT and rendered as 3D models using a commercially available software package (Mimics). Linear and angular measurements were performed using a CMM machine, the software package, and a dial caliper or goniometer. The deviation of the measurements from the CMM data was compared using ANOVA. The interobserver reliability of both the manual and computer-generated measurements was calculated.Results: The mean difference between the CMM distances and those measured manually and with the software was 2.12 ± 1.20 mm and 1.57 ± 1.05 mm, respectively. The mean difference between the CMM angular measurements and the angular measurements performed manually and with the software was 4.07 ± 4.70° and 1.62 ± 1.32°, respectively. In all cases, the manual measurements were significantly less accurate (p < 0.0001) and there was a high degree of interobserver reliability.Conclusions: Computer-generated measurements taken from three-dimensionally reconstructed models are more accurate than manual measurements and are within 2 mm and 2° of measurements performed with a CMM. These measurements have high interobserver reliability.

Automatic construction of 2D and 3D models during robot inspection

PurposeAims to make a mobile robot able to build accurate 2D and 3D models of its environment while navigating autonomously.Design/methodology/approach2D map building is performed using a laser range scanner. The map is used by the robot to both localize itself and recognize places already explored. This is the well‐known simultaneous localization and mapping (SLAM) problem. 3D model reconstruction, instead, uses computer vision techniques based on feature extraction and matching.FindingsThe experimental results illustrate the validity and accuracy of the reconstructed maps of the environment and enable the robot to navigate autonomously in indoor environments, such as museums, hospitals, airports, offices and so on. Such a robot can play a major role in different tasks such as surveillance, image‐based rendering, remote fruition of hardly accessible sites, monitoring and maintenance applications, reverse engineering in construction. In these areas accurate 3D models in addition to 2D maps can convey a lot of very useful information.Originality/valueThe main contribution of the paper is an interesting integration of different algorithms in an experimental platform that performs 2D map building using a laser range scanner, autonomous navigation and 3D reconstruction of the areas of particular interest.

Extending the limits of earth data visualization and exploration

Increasingly powerful tools for geoscientific mapping, 3D visualization, and analysis respond to geoscientists’ rising need for greater power, precision and productivity in accessing, integrating, and understanding large volumes of diverse data. Louis Racic, industry product manager, Geosoft, describes some of the practical implications for the minerals and other industries. Twenty years ago, earth exploration and computers were often thought of as mutually exclusive. Today, they are inseparable, and software is a critical enabler of timely and informed geoscience decision-making. Industry’s need to efficiently access, integrate, and visualize larger volumes and diversity of available data have given rise to more powerful productivity tools for geoscientific data access, analytics, mapping, and 3D visualization. Desktop applications are routinely used to collect and view sample data for quick site assessment in the field, while robust mapping systems in the office provide sophisticated visualizations and construction of complex 3D earth models to guide subsurface exploration. In this article, we look at some of the factors driving demand for more power, precision, and productivity and provide industry examples that illustrate the effectiveness of enabling technology in solving current data and workflow efficiency challenges in the geosciences. Industry data needs Earth science projects are growing in complexity and scope. As the generation and availability of digital, geoscientific data grows, geoscientists are increasingly pressed to deliver and account for results. They must meet the challenge of accessing, integrating, and strategically using this rising volume of data within compressed project timeframes in order to support business decision-making within all industries and across all disciplines. Easy access, frequent updating, and continual manipulation of data, in real time, are in demand throughout the lifecycle of a geoscience project – from data analysis in the field, to collaborative interpretation in team meetings, to the presentation of results in the corporate boardroom. Within mineral exploration, the need for more integrated, advanced and subtle methods is partially driven by the fact that companies are trying to find ore bodies in complex environments.. In many cases, geoscientists are working with larger volumes of geological, geophysical, and geochemical data. Exploration project data can include 500 or more drill holes, some of which are 1000 m deep or more - in combination with satellite imagery, GIS data, and surface and subsurface geology data. Geoscientists in a variety of fields now require software tools capable of efficiently processing, analyzing for statistical variation, relationships and other factors, interpreting and clearly presenting large volumes of data from multiple data sources and in diverse data formats. They must do so within a single or transparently-linked interactive environment that allows for frequent data update, modification, and enhancement.

Cardiac Three-Dimensional Magnetic Resonance Imaging and Fluoroscopy Merging

Modern nonfluoroscopic mapping systems construct 3D electroanatomic maps by tracking intracardiac catheters. They require specialized catheters and/or dedicated hardware. We developed a new method for electroanatomic mapping by merging detailed 3D models of the endocardial cavities with fluoroscopic images without the need for specialized hardware. This developmental work focused on the right atrium because of the difficulties in visualizing its anatomic landmarks in 3D with current approaches. Cardiac MRI images were acquired in 39 patients referred for radiofrequency catheter ablation using balanced steady state free-precession sequences. We optimized acquisition and developed software for construction of detailed 3D models, after contouring of endocardial cavities with cross-checking of different imaging planes. 3D models were then merged with biplane fluoroscopic images by methods for image calibration and registration implemented in a custom software application. The feasibility and accuracy of this merging process were determined in heart-cast experiments and electroanatomic mapping in patients. Right atrial dimensions and relevant anatomic landmarks could be identified and measured in all 3D models. Cephalocaudal, posteroanterior, and lateroseptal diameters were, respectively, 65+/-11, 54+/-11, and 57+/-9 mm; posterior isthmus length was 26+/-6 mm; Eustachian valve height was 5+/-5 mm; and coronary sinus ostium height and width were 16+/-3 and 12+/-3 mm, respectively (n=39). The average alignment error was 0.2+/-0.3 mm in heart casts (n=40) and 1.9 to 2.5 mm in patient experiments (n=9), ie, acceptable for clinical use. In 11 patients, reliable catheter positioning and projection of activation times resulted in 3D electroanatomic maps with an unprecedented level of anatomic detail, which assisted ablation. This new approach allows activation visualization in a highly detailed 3D anatomic environment without the need for a specialized nonfluoroscopic mapping system.

Computational Exploration of the Catalytic Mechanism of Dopamine β-Monooxygenase: Modeling of Its Mononuclear Copper Active Sites

Dopamine hydroxylation by the copper-superoxo, -hydroperoxo, and -oxo species of dopamine beta-monooxygenase (DBM) is investigated using theoretical calculations to identify the active species in its reaction and to reveal the key functions of the surrounding amino acid residues in substrate binding. A 3D model of rat DBM is constructed by homology modeling using the crystal structure of peptidylglycine alpha-hydroxylating monooxygenase (PHM) with a high sequence identity of 30% as a template. In the constructed 3D model, the CuA site in domain 1 is coordinated by three histidine residues, His265, His266, and His336, while the CuB site in domain 2 is coordinated by two histidine residues, His415 and His417, and by a methionine residue, Met490. The three Glu268, Glu369, and Tyr494 residues are suggested to play an important role in the substrate binding at the active site of DBM to enable the stereospecific hydrogen-atom abstraction. Quantum mechanical/molecular mechanical (QM/MM) calculations are performed to determine the structure of the copper-superoxo, -hydroperoxo, and -oxo species in the whole-enzyme model with about 4700 atoms. The reactivity of the three oxidants is evaluated in terms of density-functional-theory calculations with small models extracted from the QM region of the whole-enzyme model.

Dynamic fault seal analysis and flow pathway modelling in three-dimensional basin models

Faults are important elements of petroleum systems that influence the migration and trapping of hydrocarbons in sedimentary basins. When faults undergo displacement, their fluid transmissibility properties change as a result of juxtaposing lithologies across the fault, by smearing semi-permeable or impermeable argillaceous rocks within fault zones and by pumping or valving aqueous fluids. We describe here a 4D hydrocarbon migration model that incorporates juxtaposition and argillaceous smear processes. The technique uses the geometries of strata that are cut by faults and their physical properties to construct 3D models in which the evolution of cross-fault relationships can be calculated and the development of fault-zone argillaceous smear predicted. Hydrocarbon migration pathways through faulted structures are then investigated with a 4D migration model based on invasion percolation (IP) techniques. The controls on hydrocarbon migration have been investigated for fieldwork-derived models of rock volumes from the Moab Fault, Utah, USA to test the modelling techniques against reality. As a result predominantly of argillaceous smear, hydrocarbons are shown to accumulate in the hanging wall of parts of the modelled section of the Moab Fault, but leak across juxtaposed sandstones elsewhere on the fault to produce footwall accumulations. The techniques are then applied to a seismically derived model of the Artemis Field, UK Southern North Sea, to demonstrate how hydrocarbon charging history and pathways are influenced by fault geometries. Multiple model realizations enable the risk associated with charging of individual fault compartments to be assessed.

Improving integrated interpretation accuracy and efficiency using a single consistent reservoir model from seismic to simulation

The principal problems associated with the construction of 3D models for integrated reservoir interpretation are: • the complexity of the model building process and the difficulty of iterating the process, • the time required to define the model and the computational time to build it, and • the accuracy of the geometry and correctness of the topology of the model constructed.

Appearance-based virtual view generation from multicamera videos captured in the 3-d room

We present an appearance-based virtual view generation method that allows viewers to fly through a real dynamic scene. The scene is captured by multiple synchronized cameras. Arbitrary views are generated by interpolating two original camera-views near the given viewpoint. The quality of the generated synthetic view is determined by the precision, consistency and density of correspondences between the two images. All or most of previous work that uses interpolation extracts the correspondences from these two images. However, not only is it difficult to do so reliably (the task requires a good stereo algorithm), but also the two images alone sometimes do not have enough information, due to problems such as occlusion. Instead, we take advantage of the fact that we have many views, from which we can extract much more reliable and comprehensive 3D geometry of the scene as a 3D model. Dense and precise correspondences between the two images, to be used for interpolation, are obtained using this constructed 3D model.

3D Scanning Technology: Capabilities and Issues

The recent evolution of graphics technology makes it possible to manage very complex models on inexpensive platforms. These impressive rendering capabilities should be paired with detailed and accurate digital models. The construction of high quality 3D models is made easier by the increasing diffusion of automatic 3D measuring devices (often called 3D scanners). These allow to build highly accurate models of real 3D objects in a cost- and time-effective manner. The talk will present the capabilities of this technology focusing mainly on a particular application context: the acquisition of Cultural Heritage artifacts. The peculiar requirements of this domain (high accuracy in the acquisition of both shape and surface appearance, expected low cost and easiness of use of the tools) make it a perfect application example. This talk aims also at presenting and discussing the main issues in the acquisition of accurate 3D models, together with some limitations of current hardware and software tools. Some examples of the results of current projects will be shown.

Sequence analyses and comparative modeling of fly and worm fibroblast growth factor receptors indicate that the determinants for FGF and heparin binding are retained in evolution

The presence of a large number of fibroblast growth factors (FGFs) and multiple splice forms of their receptors (FGFRs) in higher vertebrates makes the three-dimensional (3D) analysis of FGF interactions with their receptors a formidable task. The situation differs in Caenorhabditis elegans (worm) and Drosophila melanogaster (fruit fly), where only one or two FGF and FGFR sequences have been identified. Structural studies of the FGF–FGFR complexes in such primitive organisms should reveal the basic features of the ligand–receptor interactions as they first emerged through evolution. We have analysed the sequences of worm and fly FGFs and FGFRs and used the recently determined crystal structure of the human FGF1–FGFR2–heparin ternary complex [Pellegrini, L., Burke, D.F., von Delft, F., Mulloy, B. and Blundell, T.L. (2000) Nature 407, 1029–34] to construct 3D models of the homologous complexes. In spite of a low sequence similarity with their human counterparts, key structural features required for ligand–receptor and protein–heparin binding in humans are conserved in the fly and worm FGF–FGFR–heparin complexes. Analyses of the models show that tertiary interactions that are not conserved in sequence are maintained through novel interactions or complementary mutations in the fly and worm sequences. The overall charge distributions observed in the human FGF–FGFR–heparin complex are retained in the fly and worm models. The arginine residue at position 253 in the linker region between the Ig-like domains D2 and D3 in the wild type fly and worm sequences is particularly striking, as the Pro253Arg mutation in humans is responsible for Apert syndrome. This change may enhance the affinity of receptors for their FGF molecules as observed in Apert mutants.

Detection and modeling of buildings from multiple aerial images

Automatic detection and description of cultural features, such as buildings, from aerial images is becoming increasingly important for a number of applications. This task also offers an excellent domain for studying the general problems of scene segmentation, 3D inference, and shape description under highly challenging conditions. We describe a system that detects and constructs 3D models for rectilinear buildings with either flat or symmetric gable roofs from multiple aerial images; the multiple images, however, need not be stereo pairs (i.e., they may be acquired at different times). Hypotheses for rectangular roof components are generated by grouping lines in the images hierarchically; the hypotheses are verified by searching for presence of predicted walls and shadows. The hypothesis generation process combines the tasks of hierarchical grouping with matching at successive stages. Overlap and containment relations between 3D structures are analyzed to resolve conflicts. This system has been tested on a large number of real examples with good results, some of which are included in the paper along with their evaluations.

3D Face Modeling from Perspective-Views and Contour-Based Generic-Model

Three-dimensional human head modeling is useful in video-conferencing or other virtual reality applications. However, manual construction of 3D models using CAD tools is often expensive and time-consuming. Here we present a robust and efficient method for the construction of a 3D human head model from perspective images viewing from different angles. In our system, a generic head model is first used, then three images of the head are required to adjust the deformable contours on the generic model to make it closer to the target head. Our contributions are as follows. Our system uses perspective images that are more realistic than orthographic projection approximations used in earlier works. Also, for shaping and positioning face organs, we present a method for estimating the camera focal length and the 3D coordinates of facial landmarks when the camera transformation is known. We also provide an alternative for the 3D coordinates estimation using epipolar geometry when the extrinsic parameters are absent. Our experiments demonstrate that our approach produces good and realistic results.

Prediction of protein structure: the problem of fold multiplicity.

Three-dimensional (3D) models of four CASP3 targets were calculated using a simple modeling procedure that includes prediction of regular secondary structure, analysis of possible beta-sheet topologies, assembly of amphiphilic helices and beta-sheets to bury their nonpolar surfaces, and adjustment of side-chain conformers and loops to provide close packing and saturation of the "hydrogen bond potential" (exposure of all polar groups to water or their involvement in intramolecular hydrogen bonds). It has been found that this approach allows construction of 3D models that, in some cases, properly reproduce the structural class of the protein (such as beta-barrel or beta-sandwich of definite shape and size) and details of tertiary structure (such as pairing of beta-strands), although all four models were more or less incorrect. Remarkably, some models had fewer water-exposed nonpolar side-chains, more hydrogen bonds, and smaller holes than the corresponding native structures (although the models had a larger water-accessible nonpolar surface). The results obtained indicate that hydrophobicity patterns do not unequivocally determine protein folds, and that any ab initio or fold recognition methods that operate with imprecise potential energy functions, or use crude geometrical approximations of the peptide chain, will probably produce many different nonnative structures.

Prediction of protein structure: The problem of fold multiplicity

Three-dimensional (3D) models of four CASP3 targets were calculated using a simple modeling procedure that includes prediction of regu- lar secondary structure, analysis of possible b-sheet topologies, assembly of amphiphilic helices and b-sheets to bury their nonpolar surfaces, and adjust- ment of side-chain conformers and loops to provide close packing and saturation of the ''hydrogen bond potential'' (exposure of all polar groups to water or their involvement in intramolecular hydrogen bonds). It has been found that this approach allows construction of 3D models that, in some cases, prop- erly reproduce the structural class of the protein (such as b-barrel or b-sandwich of definite shape and size) and details of tertiary structure (such as pairing of b-strands), although all four models were more or less incorrect. Remarkably, some models had fewer water-exposed nonpolar side-chains, more hydrogen bonds, and smaller holes than the corre- sponding native structures (although the models had a larger water-accessible nonpolar surface). The results obtained indicate that hydrophobicity patterns do not unequivocally determine protein folds, and that any ab initio or fold recognition methods that operate with imprecise potential en- ergy functions, or use crude geometrical approxima- tions of the peptide chain, will probably produce many different nonnative structures. Proteins Suppl

9731451 Development of a system to construct 3D models from 2D drawings Hiroshi Sakai, Shuzaburo Fujii (Aisin Seiki Co., Ltd.), Ryo Haruta (Nihon Unisys, Ltd.)

9731451 Development of a system to construct 3D models from 2D drawings Hiroshi Sakai, Shuzaburo Fujii (Aisin Seiki Co., Ltd.), Ryo Haruta (Nihon Unisys, Ltd.)

Advances in the molecular understanding of gonadotropins-receptors interactions

The extracellular domain (ECD) of gonadotropin receptors belong to the leucine-rich repeat (LRR) protein superfamily and their transmembrane domain (TMD) is characteristic of the seven α-helices G-protein-coupled receptors (GPCR). The availability of the X-ray strutures of porcine ribonuclease inhibitor (RI), a LRR protein, and bacteriorhodopsin (bR) allows the construction of 3D models of the ECD and the TMD of gonadotropin receptors, respectively. The predicted models are to a large extent consistent with currently available biochemical and mutational data. The models provide a reliable basis for understanding how the hormone binds and activates its receptor. The ECD, in particular the LRR region, serves as a baseball glove which efficiently catches the large hormone and optimally orient the appropriate parts of it for interaction with the seven-transmembrane-helix domain of the receptor. This in turn is expected to lead to a conformational change to be sensed by the appropriate G-protein complex leading to the stimulation of cAMP synthesis and steroids production.

Two-Stage Dynamic Deformation for Construction of 3D Models

A procedure for 3D model construction from sparsely and irregularly sampled points is presented. A two-stage dynamic deformation process is presented which is designed to produce desirable mesh properties despite difficult data characteristics. In a first phase, a mesh of springs is snapped down to the convex hull of the data. In the second phase, a pseudo-gravity model is used to attract the mesh points into concave surface patches. This modeling technique is a new contribution to dynamic modeling methods. This process reduces the undesirable effects of oversmoothness, local concentration, and folding that result from the sparsity and randomness of sampled data. Our experiments show that the proposed deformation process preserves to some extent both the shape and size uniformities of the patches constituting models. Furthermore, our modeling process fits surfaces with prominent concavities without prior segmentation of input data.