Realistic 3D Model Research Articles

High-Resolution Geologic Modelling and Co2 Flow Simulation of a Realistic Clastic Deltaic 3d Model Derived from a Laboratory Flume Tank Experiment

High-Resolution Geologic Modelling and Co2 Flow Simulation of a Realistic Clastic Deltaic 3d Model Derived from a Laboratory Flume Tank Experiment

Beam-Based Tether Dynamics and Simulations using Finite Element Model

Building on the beam equation, this paper derives a realistic and versatile 3D model of tether/cable/umbilical dynamics and approximates it via the Finite Element Method (FEM). This FEM implementation/approximation can be executed in real time, when the model accuracy is not of prime concern for the application at hand, or in an offline fashion, when the model accuracy is essential. Our model allows for different time-varying forces (e.g., wind gusts, sea currents, waves, etc.) acting along the cable. However, unlike the related works, where tether bending and stretching are mutually independent resulting in unrealistic tether elongations, our implementation takes into account the tether length, which in turn imposes coupling among transversal and longitudinal tether displacements. Our work is motivated by applications of tethered robots such as Unmanned Underwater Vehicles (UUVs), most commonly Remotely Operated Vehicles (ROVs) and Unmanned Aerial Vehicles (UAVs). In such applications, the tether is typically kept under tension leading to “small” tether displacements and the absence of deformations and entanglements, which is why the beam equation is selected to start with. However, partially owing to the attention paid to the tether length, our dynamic model behaves well even for “larger” displacements as illustrated in Gazebo ROS using a tethered ROV whereas the tether itself is implemented in Matlab via FEM.

Interactive Virtual Scanning Electron Microscope Inspired by 3D Game-Design

The scanning electron microscope (SEM) has evolved to become an indispensable tool for research and education in engineering, physics, nanotechnology, geosciences, materials science, biological sciences and other fields. However, training on a physical SEM is costly, time consuming, and often unavailable in economically disadvantaged areas. Advances in computer technology have made interactive three-dimensional (3D) virtual laboratory an effective tool for training in medicine and many engineering and technology fields. In the current work, in order to provide cost-effective hands-on training, a virtual 3D SEM was developed using the game development engine <i>Unity 3D</i>. It contains realistic 3D models of the physical components, created using <i>3ds Max^®</i>, a software for 3D modeling and rendering. The components are manipulated with scripts programmed using C# and JavaScript and then paired with the corresponding model. Users may view and operate the virtual instrument, save images for further analysis, and write a report. The developed virtual SEM was tested on diverse groups of users at multiple institutions, each divided to treatment and control groups. Feedback from these tests was collected and used for improvements in the overall quality of the simulated experience. In addition, users reported the experience of training on the virtual SEM as enjoyable.

MODELING INTRAORGAN VASCULATURE USING PROCEDURAL AND MATHEMATICAL SPACE TRANSFORMATIONS

Background. The electronic methods in medicine are getting more widespread. The COVID-19 pandemic forced remote IT technologies to develop. It is necessary to create medical e-learning systems, in particular, to study anatomy of human organ vasculatures.&#x0D; Purpose. To create universal and realistic 3d-model of intraorgan vasculatures based on the vasculature morphometry results.&#x0D; Materials and methods. Morphometric data of real vascular networks, geometric modeling in plane and in scape, procedural spatial transformation of the vasculature according to the law of a logarithmic spiral were used.&#x0D; Results. A two-staged sequence for construction a geometric 3d-model is proposed. The model is built of the units of vasculature, which are called bifurcations (dichotomies). At the first stage, mathematical 2d-model of a vascular network fragment is build based on morphometric data of the geometry of vasculature. It reflects the structure and quantitative characteristics of the vascular bifurcations (dichotomies). At the second stage, data about third special coordinate is added and a procedural 3d-model of the fragment is built. To increase the accuracy of the model, the ability to bend the vessels and to differ diameters of their starting and ending points have been added.&#x0D; Conclusion. The universal 3d-model of a tree-like structure is presented as a visualization of the intraorgan vasculature. These models can be used as visual teaching aids in online education environment. To increase the informative and educational value of the model, visual images of various pathologies of the vasculature can be added.

2D numerical investigations derived from a 3D dragonfly wing captured with a high-resolution micro-CT.

BACKGROUND: Due to their corrugated profile, dragonfly wings have special aerodynamic characteristics during flying and gliding.OBJECTIVE: The aim of this study was to create a realistic 3D model of a dragonfly wing captured with a high-resolution micro-CT. To represent geometry changes in span and chord length and their aerodynamic effects, numerical investigations are carried out at different wing positions.METHODS: The forewing of a Camacinia gigantea was captured using a micro-CT. After the wing was adapted an error-free 3D model resulted. The wing was cut every 5 mm and 2D numerical analyses were conducted in Fluent 2020 R2 (ANSYS, Inc., Canonsburg, PA, USA).RESULTS: The highest lift coefficient, as well as the highest lift-to-drag ratio, resulted at 0 mm and an angle of attack (AOA) of 5. At AOAs of 10 or 15, the flow around the wing stalled and a Kármán vortex street behind the wing becomes visible.CONCLUSIONS: The velocity is higher on the upper side of the wing compared to the lower side. The pressure acts vice versa. Due to the recirculation zones that are formed in valleys of the corrugation pattern the wing resembles the form of an airfoil.

VISmaF: Synthetic Tree for Immersive Virtual Visualization in Smart Farming. Part I: Scientific Background Review and Model Proposal

Computer-Generated Imagery (CGI) has received increasing interest in both research and the entertainment industry. Recent advancements in computer graphics allowed researchers and companies to create large-scale virtual environments with growing resolution and complexity. Among the different applications, the generation of biological assets is a relevant task that implies challenges due to the extreme complexity associated with natural structures. An example is represented by trees, whose composition made by thousands of leaves, branches, branchlets, and stems with oriented directions is hard to be modeled. Realistic 3D models of trees can be exploited for a wide range of applications including decision-making support, visualization of ecosystem changes over time, and for simple visualization purposes. In this review, we give an overview of the most common approaches used to generate 3D tree models, discussing both methodologies and available commercial software. We focus on strategies for modeling and rendering of plants, highlighting their accordance or not with botanical knowledge and biological models. We also present a proof of concept to link biological models and 3D rendering engines through Ordinary Differential Equations.

HBIM for the Characteristics of Korean Traditional Wooden Architecture: Bracket Set Modelling Based on 3D Scanning

Historic building information modelling (HBIM) is a technology that documents and analyses 3D model information for reverse engineering using laser scan and image survey data of buildings having heritage value. In the case of traditional Korean wooden architectures, especially the bracket-sets of buildings, there is a limit to accuracy, owing to non-visible seams. Thus, in this study, mesh modelling is conducted using point-cloud data of the entire Seoikheon building of Jeonju Pungpajigwan, which is a national cultural property of Korea. After dismantling the building, scanning the members and cross-checking the cloud data, it was possible to create a realistic Rhino 3D model that includes joints of the bracket set. Hence, it is possible to implement a 3D model in Revit that reflects the unique shapes and characteristics of traditional wooden architectures. The resultant model not only provides a platform of various historic building information, but it can also be used as a digital twin to understand deformation and damage to wooden joints.

Pre‐dam valley reconstruction based on archival spatial data sources: Methods, accuracy, and 3D printing possibilities

AbstractArchival spatial data sources (maps and aerial photographs) allow reconstruction and 3D visualization of landscapes that have been altered by human activity. This article is dedicated to the reconstruction of the 300 km‐long pre‐dam valley of the Vltava River (Czech Republic, Europe) inundated by nine reservoirs built between 1930 and 1992. We used methods based on archival aerial photographs and old maps to reconstruct pre‐dam georelief, which is exceptional because the total area subject to the reconstruction is 1,670 km2. We found that old maps are preferred for terrain reconstruction. The map series “State Map Derived 1:5,000” released between 1950 and 1959 was chosen as the most suitable data source for the pre‐dam valley reconstruction because this map series covers the entire area of interest with elevation information. Based on the processed maps, more than 26,000 km of contour lines were derived by semi‐automatic vectorization. The resulting pre‐dam digital elevation model (DEM) was created using a combination of interpolation techniques. We demonstrated that the methods used for georelief reconstruction under standard conditions should be used carefully while working with such large areas. Geostatistical analysis was performed to verify the accuracy of the resulting DEM. The differences between the model and LiDAR surveyed data were analyzed from three points of view: spatial autocorrelation, normality, and elevation stability. We tested several 3D printing methods for producing a realistic 3D model with a texture applied. The computer numerical control (CNC) milling method was chosen to produce 3D models of the three reservoirs at scales of 1:8,000 and 1:6,000.

Full-Atom Model of the Agonist LPS-Bound Toll-like Receptor 4 Dimer in a Membrane Environment.

The Toll‐like receptor 4 (TLR4)/myeloid differentiation factor 2 (MD‐2) innate immunity system is a membrane receptor of paramount importance as therapeutic target. Its assembly, upon binding of Gram‐negative bacteria lipopolysaccharide (LPS), and also dependent on the membrane composition, finally triggers the immune response cascade. We have combined ab‐initio calculations, molecular docking, all‐atom molecular dynamics simulations, and thermodynamics calculations to provide the most realistic and complete 3D models of the active full TLR4 complex embedded into a realistic membrane to date. Our studies give functional and structural insights into the transmembrane domain behavior in different membrane environments, the ectodomain bouncing movement, and the dimerization patterns of the intracellular Toll/Interleukin‐1 receptor domain. Our work provides TLR4 models as reasonable 3D structures for the (TLR4/MD‐2/LPS)2 architecture accounting for the active (agonist) state of the TLR4, and pointing to a signal transduction mechanism across cell membrane. These observations unveil relevant molecular aspects involved in the TLR4 innate immune pathways and will promote the discovery of new TLR4 modulators.

Linearization of Thermal Equivalent Temperature Calculation for Fast Thermal Comfort Prediction

Virtual simulations and calculations are a key technology for future development methods. A variety of tools and methods for calculating thermal comfort have not gained sufficient acceptance in practice due to their inherent complexity. This article investigates alternative means of determining thermal comfort, namely, the linearization of the equivalent temperature calculation. This enables a wide range of users to evaluate thermal comfort in a fast and easy manner, for example, for energy efficiency simulation. A flow and thermal model were created according to the requirements of DIN EN ISO 14505 to determine heat transfer coefficients under calibration conditions. The model to simulate the equivalent temperature in calibration conditions comprises a geometrically realistic 3D model of a human test person according to the standard. The influence of the turbulence model, as well as the influence of the equivalent temperature on the heat transfer coefficient in calibration conditions, was investigated. It was found that the dependence of the equivalent temperature is mandatory. The dependence between the heat transfer and the equivalent temperature was taken into account with a continuous linearization approach. An equation-based implementation methodology is proposed, enabling a quick implementation of comfort evaluation in future simulation models. Two test cases show the capabilities of the new model and its application in future work.

Impact of sedimentary facies on machine learning of acoustic impedance from seismic data: Lessons from a geologically realistic 3D model

We have developed a new machine-learning (ML) workflow that uses random forest (RF) regression to predict sedimentary-rock properties from stacked and migrated 3D seismic data. The training, validation, and testing are performed with 40 features extracted from a geologically realistic 46 × 66-trace model built in the Miocene Powderhorn Field in South Texas. We focus on the responses of the RF model to sedimentary facies and the strategies adopted to achieve better prediction with various data conditions. We apply explained variation (R2) and root-mean-square (rms) prediction errors to map the relationship between the quality of prediction and the sedimentary facies. In the single-well model, R2 and rms error maps highly resemble sand-percentage maps, or lithofacies maps, showing the facies control on the quality of the ML model. We observe that training with a small well data set (1–10 wells) leads to low and unstable test scores (R2 = 0.2–0.7). The R2 score increases and stabilizes with more (as many as 1000) training wells (R2 = 0.7–0.9), realizing the effective correction of facies bias. The stratigraphic and spatial features are useful and should be used. Weak to moderate random noise (−20 to −15 dB) slightly lowers the training score (R2 &lt; 0.05) and should not be a major concern. Sparse well-supported models can outperform linear regression and model-based inversion and can be useful if caution is exercised. In the best-case scenario (500 wells), the predicted model largely duplicates the true model with a significant improvement in accuracy (R2 = 0.85) and stability. Such results can be applied in most, if not all, exploration and production practices.

Documenting Skeletal Scatters in Obstructed Wooded Environments Using Close-Range Photogrammetry

Forensic scenes involving human skeletal remains in obstructed wooded environments are challenging to document. One potential solution is to document the scene in 3D utilizing close-range photogrammetry (CRP). This method enables the generation of realistic 3D models and accurate plan-view maps of the scene. The purpose of this research was to explore the use of CRP to preserve contextual information of simulated scenes involving scattered human remains in obstructed wooded environments. The main goal was to improve CRP methodology as well as demonstrate how to incorporate this method into the forensic archaeology documentation protocol. Two large skeletal scatters were documented to test the capabilities of CRP in an obstructed environment. Photographs were collected freehand and 3D models were processed using Agisoft Metashape Professional. Accuracy was assessed through visual analysis, root-mean square (RMS) reprojection errors, and total scale bar errors. While visual errors were present when zoomed in, the RMS reprojection and scale bar errors still indicated highly accurate models. However, the wooded environment presented numerous challenges that made utilizing CRP more difficult. Therefore, guidelines were outlined for documenting skeletal scatters in wooded environments using CRP, with a focus on addressing variables that can affect image quality. Overall, CRP is a viable method for documenting complex scenes in wooded environments which should be incorporated into forensic archaeological protocols.

Single Image Tree Reconstruction via Adversarial Network

Realistic 3D tree reconstruction is still a tedious and time-consuming task in the graphics community. In this paper, we propose a simple and efficient method for reconstructing 3D tree models with high fidelity from a single image. The key to single image-based tree reconstruction is to recover 3D shape information of trees via a deep neural network learned from a set of synthetic tree models. We adopted a conditional generative adversarial network (cGAN) to infer the 3D silhouette and skeleton of a tree respectively from edges extracted from the image and simple 2D strokes drawn by the user. Based on the predicted 3D silhouette and skeleton, a realistic tree model that inherits the tree shape in the input image can be generated using a procedural modeling technique. Experiments on varieties of tree examples demonstrate the efficiency and effectiveness of the proposed method in reconstructing realistic 3D tree models from a single image.

Use of 3D printing as a simulation tool for trauma surgery of the pelvis

ObjectiveFractures of the pelvis are serious pathologies that can be life-threatening. Surgical treatment of complex fractures is difficult, due to the proximity of neighboring vessels and organs. Our goal was to create a practical educational simulation model printed in 3 dimensions (3D) from CT scans images of a patient who had a complex fracture of the pelvis. MethodPreoperative CT scan of a right hemi-pelvic fracture was modeled using an open source softwares such as Horos® and Meshmixer®. The free software Cura® made it possible to print bone elements and pelvic vessels using Fused Deposition Modeling technology (FDM). Negative molds were printed to pour liquid latex to represent skin, muscles and the bladder. All these elements were reassembled to create a model faithful to the patient's anatomy. ResultsA first model comprising 33 objects (1:2 scale) was produced after 39 h of cumulative printing. Three approaches were feasible among ilio-inguinal, posterior and tri-radiated approaches. Six models of plates were used to maintain fracture reduction. The external iliac vessels and the iliac psoas muscle in latex could be reclined to access the fragments of the internal iliac fossa. ConclusionOur model seems to improve the 3D vision of the anatomical region of the pelvis as a function of the recumbency. This prototype demonstrated the feasibility of using CT scans for the creation of a realistic 3D models. A new 1:1 scale model would create a real simulator for training surgical students who could practice dealing with this complex anatomical region.

A nanosecond pulsed electric field (nsPEF) can affect membrane permeabilization and cellular viability in a 3D spheroids tumor model

Three-dimensional (3D) cellular models represent more realistically the complexity of in vivo tumors compared to 2D cultures. While 3D models were largely used in classical electroporation, the effects of nanosecond pulsed electric field (nsPEF) have been poorly investigated. In this study, we evaluated the biological effects induced by nsPEF on spheroid tumor model derived from the HCT-116 human colorectal carcinoma cell line. By varying the number of pulses (from 1 to 500) and the polarity (unipolar and bipolar), the response of nsPEF exposure (10 ns duration, 50 kV/cm) was assessed either immediately after the application of the pulses or over a period lasting up to 6 days. Membrane permeabilization and cellular death occurred following the application of at least 100 pulses. The extent of the response increased with the number of pulses, with a significant decrease of viability, 24 h post-exposure, when 250 and 500 pulses were applied. The effects were highly reduced when an equivalent number of bipolar pulses were delivered. This reduction was eliminated when a 100 ns interphase interval was introduced into the bipolar pulses. Altogether, our results show that nsPEF effects, previously observed at the single cell level, also occur in more realistic 3D tumor spheroids models.

Simulation analysis on cutting forces based on surface topography of fixed abrasive wire saw

Similar to grinding, a large number of diamond abrasive particles are used on the wire saw surface to remove materials by interaction with the workpiece. Therefore, the surface morphological characteristics of the wire saw, such as particle size and cutting edge height, have important effects on cutting performance of the wire saw. In terms of the complex diversity of the geometric characteristics and the randomness of the spatial position of the abrasive particles on the wire saw, the irregular polyhedron generated by the random space plane sphere method is used to simplify the abrasive particles and the space coordinates of the abrasive centre are created by random algorithm. As a result, a more realistic 3D model of the wire saw surface is constructed. A finite element method was employed to establish a cutting force simulation model of the wire saw with multiple abrasive particles for hard and brittle materials cutting processing, and the influence of feed rate and wire saw speed on cutting force was analysed; Based on the contact arc length, the cutting force model of multiple abrasive particles is extended to the macro level of wire saw cutting, and the reliability of the proposed model is verified by 4H-SiC cutting experiments. The established finite element model for microscopic simulation of the cutting process lays a foundation for cutting force prediction, tool parameter optimization and further research on wire saw cutting mechanism.

Diagnosing and monitoring pleural effusion using parametric electrical impedance tomography - a computational 3D model and preliminary experimental results

PurposeDiagnosing and monitoring pleural effusion (PE) is challenging due unsuitability of existing modalities. In the present study, a novel parametric electrical impedance tomography (pEIT) technique, tailored to a clinically feasible system to diagnose PE is presented. MethodsAn electrical impedance tomography (EIT) numeric solver was applied to a 3D realistic normal model and five PE models to simulate sets of surface measurements. Simulations were triggered by a series of eight independent projections using five electrodes positioned around the thorax. The relative changes in the potential between the PE models and the normal model were assessed and the error in the estimated PE volume was examined at varying signal to noise ratio (SNR) levels. For experimental feasibility, measurements were performed in four healthy subjects and were correlated with the potentials that were calculated from the normal model. ResultsRelative potential changes were notable (reached until ~55%) and increased with the increasing PE volumes. Maximal error of ± 20 [mL] was obtained for SNR levels >50 [dB]. The feasibility real measurements in healthy subjects showed a strong linear correlation (R2 > 0.85) and a successful diagnosis for all subjects. ConclusionThe proposed technique can estimate PE volumes from a redundant set of measurements in a realistic 3D human model and may be utilized for monitoring PE patients.

Quality evaluation of lightweight realistic 3D model based on BIM forward design

In this paper, we assess the lightweight efficiency of the realistic 3D model data through comparative tests by introducing the realistic three-dimensional model into building information modeling (BIM) design. To meet the varied needs of engineering design in the construction field at different stages, a quality evaluation method for the lightweight realistic 3D model is proposed, with the texture quality and plane positioning accuracy of the model taken into account. The results show that the best lightweight coefficient of realistic 3D model data in film box (FBX) format is 40%. Under a lightweight coefficient at 40%, the amount of model data is reduced by 25%, with only small holes incurred in the texture, and the atness error is ±9 mm. After lightweight processing, the model meets the requirements of BIM designers for vision and plane positioning accuracy. By putting forward a data lightweight processing standard and a model evaluation method based on the idea of BIM design, we aimed to solve the challenges in applying realistic 3D models to BIM design due to the large amounts of data, thereby to lay a foundation for wider application of realistic 3D models to BIM design.

Sketch-based interface and modelling of stratigraphy and structure in three dimensions

Geological modelling is widely used to predict resource potential in subsurface reservoirs. However, modelling is often slow, requires use of mathematical methods that are unfamiliar to many geoscientists, and is implemented in expert software. We demonstrate here an alternative approach using sketch-based interface and modelling, which allows rapid creation of complex three-dimensional (3D) models from 2D sketches. Sketches, either on vertical cross-sections or in map-view, are converted to 3D surfaces that outline geological interpretations. We propose a suite of geological operators that handle interactions between the surfaces to form a geologically realistic 3D model. These operators deliver the flexibility to sketch a geological model in any order and provide an intuitive framework for geoscientists to rapidly create 3D models. Two case studies are presented, demonstrating scenarios in which different approaches to model sketching are used depending on the geological setting and available data. These case studies show the strengths of sketching with geological operators. Sketched 3D models can be queried visually or quantitatively to provide insights into heterogeneity distribution, facies connectivity or dynamic model behaviour; this information cannot be obtained by sketching in 2D or on paper. Supplementary material : Rapid Reservoir Modelling prototype (executable and source code) is available at: https://bitbucket.org/rapidreservoirmodelling/rrm . Supplementary screen recordings for the different case studies showing sketch-based modelling in action are available at https://doi.org/10.6084/m9.figshare.c.5084141 and supplementary figure S1-S4 are available at https://doi.org/10.6084/m9.figshare.c.5303043

Biovolume and surface area calculations for microalgae, using realistic 3D models

Morphology and spatial dimensions of microalgal units (cells or colonies) are among the most relevant traits of planktic algae, which have a pronounced impact on their basic functional properties, like access to nutrients or light, the velocity of sinking or tolerance to grazing. Although the shape of algae can be approximated by geometric forms and thus, their volume and surface area can be calculated, this approach cannot be validated and might have uncertainties especially in the case of complicated forms.In this study, we report on a novel approach that uses real-like 3D mesh objects to visualize microalgae and calculates their volume and surface area. Knowing these dimensions and their intraspecific variabilities, we calculated specific shape and surface area constants for more than 300 forms, covering more than two thousand taxa.Using these constants, the accurate volume and surface area can be quickly computed for each taxon and having these values, morphology-related metrics like surface area/volume ratio, the diameter of spherical equivalent can also be given quickly and accurately.Besides their practical importance, the volume and surface area constants can be considered as size-independent morphological traits that are characteristic for the microalgal shapes, and provide new possibilities of data analyses in the field of phytoplankton ecology.