Scanned 3D Model Research Articles

Optimasi Pengukuran Dinamis dari Visualisasi Model Ruangan 3D Menggunakan Sensor LiDAR dan Framework RoomPlan

Utilizing limited space to be more functional and aesthetic, such as adding furniture or using it as gardening space, can be achieved through effective room mapping. However, manual mapping methods have limitations such as inaccurate measurements, time efficiency, and also lack of room visualization. In this modern era, robotics technology has been widely applied in everyday life, one of which is the use of LiDAR sensors for room mapping. This paper discusses a room mapping system using a mobile application that utilizes LiDAR sensors. The mapping process is carried out by scanning the area to be mapped and rotating the area 360 degrees. The result of this mapping is a scanned 3D model of the room, which allows measurements from every side of the room. Research shows that the mapping results from the software created are similar in shape to actual field conditions. In addition, the measurement accuracy only has a small difference of 0.2%. It is hoped that this research can make it easier for humans to map rooms and make better use of limited space.

Assessment of the accuracy of 3D printed medical models through reverse engineering

The dimensional accuracy of additively manufactured (3D printed) medical models can be affected by various parameters. Although different methods are used to evaluate the accuracy of additively manufactured models, this study focused on the investigation of the dimensional accuracy of the medical model based the combination of reverse engineering (RE) and additive manufacturing (AM) technologies. Human femur bone was constructed from CT images and manufactured, using Fortus 450mc Industrial material extrusion 3D Printer. The additive manufactured femur bone was subsequently 3D scanned using three distinct non-contact 3D scanners. MeshLab was used for mesh analysis, while VX Elements was used for post-processing of the point cloud. A combination of the VX Inspect environment and MeshLab was used to evaluate the scanning performance. The deviation of the 3D scanned 3D models from the reference mesh was determined using relative metrics and absolute measurements. The scanners reported deviations ranging from −0.375 mm to 0.388 mm, resulting in a total range of approximately 0.763 mm with average root mean square (RMS) deviation of 0.22 mm. The results indicate that the additively manufactured model, as measured by 3D scanning, has a mean deviation with an average range of approximately 0.46 mm and an average mean value of around 0.16 mm.

Robust training for multi-view stereo networks with noisy labels

Recent multi-view stereo (MVS) works benefit a lot from deep neural networks with their great representation ability. However, top-performing networks require accurate depth ground truth rendered from scanned 3D models for training, which is quite challenging to capture in real-world scenarios. Thus, dealing with label noise contained in the dense depth labels is necessary for training when applied in complex real-world conditions, which has not been addressed before. In this paper, we investigate the effect of label noise in the ground truth depth maps by append noisy labels to the given accurate labels, and find that MVS networks are susceptible to noisy training data. To tackle this problem, we proposed a novel label noise-robust training framework for MVS networks. First, we propose a co-teaching based noise-robust training method to filter label noise contained in the dense depth ground truth, which trains two parallel network branches simultaneously and exchanges the noise selection capability to each other. Then, we present a co-training scheme that pseudo labels, the predicted depth maps that passes the geometric consistency check, are utilized as supervision to the peer network. Finally, the photometric consistency loss is introduced as additional supervision for all pixels. Experimental results demonstrate the robustness of deep MVS networks trained by our algorithm under low-level noise rate (40%) and high-level noise rate (65%), and the comparable 3D reconstruction performance to the network trained with label noise free datasets.

Accuracy of the Surface Contour of Three-Dimensional-Printed Canine Pelvic Replicas.

The aim of this study was to determine the differences in surface contour between models of native pelvic bones and their corresponding three-dimensional (3D)-printed replicas. Digital 3D models of five cadaveric hemipelves and five live dogs with contralateral pelvic fractures were generated based on computed tomographic images and 3D printed. The 3D-printed replicas underwent 3D scanning and digital 3D models of the replicas were created. The digital 3D model of each replica was superimposed onto the model of the native hemipelvis. Errors in the replicas were determined by comparing the distances of 120,000 corresponding surface points between models. The medial surface, lateral surface and dorsal surface of the acetabulum (DSA) of each hemipelvis were selected for further analysis. The root mean square error (RMSE) was compared between various selected areas using a one-way repeated measures analysis of variance, followed by a Bonferroni post-hoc test. The RMSE of the hemipelvis was 0.25 ± 0.05 mm. The RMSE significantly decreased from the medial surface (0.28 ± 0.06mm), to the lateral surface (0.23 ± 0.06mm), to the DSA (0.04 ± 0.02mm) (p < 0.001). The 3D-printed replicas were adequate in serving as a template for the pre-contouring of bone plates in fracture repair of pelvic fractures, particularly those that demand accurate reduction such as acetabular fractures.

Measurement and control of colour fidelity in scanned 3D models for heritage conservation

• 3D models of archaeological objects do not usually provide metadata colour fidelity. • Improving the colour information from 3D scanners is an open issue. • Colour calibration used in photography is applied to the modelling process. • The profiling operation improves the colour fidelity of 3D model images. Colour calibration is a common procedure in the photography of archaeological objects, and there are sufficient tools to guarantee faithful digital (images) or analogue reproductions (paper printing, screen or display projectors, etc.). The 3D models obtained both photogrammetrically and, above all, by means of 3D scanners have not yet reached this development and are often constructed without much attention to the colourimetric quality of the result. Because of these factors, the present work has two objectives: 1) to measure the colour fidelity of 3D models to diagnose potential quality problems and 2) to propose a data collection and processing methodology that allows a significant improvement in the colour fidelity of 3D models built by means of 3D scanners. The methodology of colour calibration used in photography is applied to the modelling process. The construction and application of an ICC (International Colour Consortium) profile on the textures significantly reduce the overall error.

Mobile3DScanner: An Online 3D Scanner for High-quality Object Reconstruction with a Mobile Device.

We present a novel online 3D scanning system for high-quality object reconstruction with a mobile device, called Mobile3DScanner. Using a mobile device equipped with an embedded RGBD camera, our system provides online 3D object reconstruction capability for users to acquire high-quality textured 3D object models. Starting with a simultaneous pose tracking and TSDF fusion module, our system allows users to scan an object with a mobile device to get a 3D model for real-time preview. After the real-time scanning process is completed, the scanned 3D model is globally optimized and mapped with multi-view textures as an efficient postprocess to get the final textured 3D model on the mobile device. Unlike most existing state-of-the-art systems which can only scan homeware objects such as toys with small dimensions due to the limited computation and memory resources of mobile platforms, our system can reconstruct objects with large dimensions such as statues. We propose a novel visual-inertial ICP approach to achieve real-time accurate 6DoF pose tracking of each incoming frame on the front end, while maintaining a keyframe pool on the back end where the keyframe poses are optimized by local BA. Simultaneously, the keyframe depth maps are fused by the optimized poses to a TSDF model in real-time. Especially, we propose a novel adaptive voxel resizing strategy to solve the out-of-memory problem of large dimension TSDF fusion on mobile platforms. In the post-process, the keyframe poses are globally optimized and the keyframe depth maps are optimized and fused to obtain a final object model with more accurate geometry. The experiments with quantitative and qualitative evaluation demonstrate the effectiveness of the proposed 3D scanning system based on a mobile device, which can successfully achieve online high-quality 3D reconstruction of natural objects with larger dimensions for efficient AR content creation.

Topological characteristics and mechanical properties of uniaxially thermoformed auxetic foam

We present here a simplified procedure to manufacture auxetic PU foam via a single direction thermoforming compression process applied to conventional (pristine) open cell foam samples. The auxetic foams produced here have a Poisson’s ratio ν21 ranging from −1 to 0 in the 1–2 plane and a tangent modulus Et2 ranging from 0.2 MPa to 2 MPa. X-ray μ-CT and 3D skeletonization enabled the extraction of the topological parameters of the pristine and the auxetic foams. The auxetic foam is transverse isotropic with cell structures exhibiting a re-entrant shape along the thermoforming compression direction 1. More ribs are also oriented within the transverse plane 2–3, in which the stiffness is larger. Tensile and compression quasi-static tests have been carried out on samples cut along different directions and having various thermoforming compression ratios rc. Auxeticity is present in the in 1–2 plane only for compression ratios between 40% and 80%. Finite Element models for the pristine and auxetic foams have also been built from the μ-CT scanned 3D models. The numerical results show a good agreement with the experimental data and help explaining the deformation mechanisms of these auxetic foams.

Digital 3D models of theropods for approaching body-mass distribution and volume

The aim of this work is to obtain diverse morphometric data from digitized 3D models of scientifically accurate palaeoreconstructions of theropods from eight representative families. The analysed polyvinyl chloride (PVC) models belong to the genera Coelophysis, Dilophosaurus, Ceratosaurus, Allosaurus, Baryonyx, Carnotaurus, Giganotosaurus, and Tyrannosaurus. The scanned 3D models were scaled considering different body-size estimations of the literature. The 3D analysis of these genera provides information on the skull length and body length that allows for recognition of major evolutionary trends. The skull length/body length in the studied genera increases according with the size of the body from the smallest Coelophysis with a ratio of 0.093 to ratios of 0.119–0.120 for Tyrannosaurus and Giganotosaurus, the largest study theropods. The study of photogrammetric 3D models also provides morphometric information that cannot be obtained from the study of bones alone, but knowing that all reconstructions begin from the fossil bones, such as the surface/volume ratio (S/V). For the studied theropod genera surface/volume ratio ranges from 35.21 for Coelophysis to 5.55 for Tyrannosaurus. This parameter, closely related to the heat dissipation, help in the characterization of the metabolism of extinct taxa. Accordingly, slender primitive forms of the Early Jurassic (i.e. Coelophysis and Dilophosaurus) had relatively smaller skulls and higher mass-specific metabolic rates than the robust large theropods of the Cretaceous (i.e. Giganotosaurus and Tyrannosaurus). This work presents a technique that, when applied to proper dinosaur models, provides extent and accurate data that may help in diverse study areas within the dinosaur palaeontology and palaeobiology.

THE CONCEPTUAL PRINCIPLES OF USING DIGITAL 3D MODEL AS A MEANS OF COGNITION AND REPRESENTATION OF SIGNS OF CRIMINAL OFFENSE

The article forms the conceptual principles of use of digital 3D model as means of cognition and display of signs of a criminal offense in criminal proceedings. A 3D model can be defined as a digital, three-dimensional image of an object, which reflects its external structure and color, accurately and proportionally reproduces the ratio of its spatial features. It can directly contain information about the shape, proportions, color and mutual placement in space of the elements of the original object. Provided the manufacturing technology is followed, the model is isomorphic to original object. Such a model serves as a means of cognition and reflection of forensically significant features of a criminal offense. The main methods for making 3D models are reconstruction (modeling) and scanning. 3D reconstruction (or 3D modeling) can be defined as the process of reproducing a 3D model of a forensic significant object based on information about it contained in the materials of criminal proceedings. The reconstructed models can be used during investigative (search) actions and for solving organizational problems. 3D scanning consists in the direct fixation of the external spatial features of the object using a special software and hardware complex, followed by the formation of a digital three-dimensional model of the object. Subject to compliance with the procedural requirements for the use of technical means of fixing forensically significant information, scanned 3D models will be sources of evidentiary information in criminal proceedings. 3D scanning is a promising method for recording the course and results of an inspection of the scene of an incident, inspection of a corpse or things; it can be used for fixing signs of a person's appearance, as well as for solving identification and diagnostics tasks in forensic activities. The invariability of the 3D model can be ensured by calculating the hash of the file that contains it.

Parametric Blending of Hole Patches Based on Shape Difference

A triangular mesh obtained by scanning 3D models typically contains holes. We present an effective technique for filling a hole in a triangular mesh in geometric modeling. Simple triangulation of a hole is refined and remeshed iteratively to generate an initial patch. The generated patch is then enhanced to become a target patch by minimizing the variation of principal curvatures. In discrete approximation, this produces a third-order Laplacian system of sparse symmetric positive definite matrix, and the symmetry can efficiently be used to find the robust solutions to the given Laplacian system. Laplacian smoothing of the target patch is defined as a source patch. The shape difference between two corresponding vertices of the source and the target patches is measured in terms of Euclidean distance and curvature variation. On the basis of the shape difference and a user-specified control parameter, different blending weights are determined for each vertex, and the final patch is generated by blending two patches. We demonstrate the effectiveness of our technique by discussing several examples. The experimental results show that our technique can effectively restore salient geometric features of the original shape.

Can I Pour Into It? Robot Imagining Open Containability Affordance of Previously Unseen Objects via Physical Simulations

Open containers, i.e., containers without covers, are an important and ubiquitous class of objects in human life. In this letter, we propose a novel method for robots to “imagine” the open containability affordance of a previously unseen object via physical simulations. The robot autonomously scans the object with an RGB-D camera. The scanned 3D model is used for open containability imagination which quantifies the open containability affordance by physically simulating dropping particles onto the object and counting how many particles are retained in it. This quantification is used for open-container vs. non-open-container binary classification (hereafter referred to as open container classification). If the object is classified as an open container, the robot further imagines pouring into the object, again using physical simulations, to obtain the pouring position and orientation for real robot autonomous pouring. We evaluate our method on open container classification and autonomous pouring of granular material on a dataset containing 130 previously unseen objects with 57 object categories. Although our proposed method uses only 11 objects for simulation calibration, its open container classification aligns well with human judgements. In addition, our method endows the robot with the capability to autonomously pour into the 55 containers in the dataset with a very high success rate. We also compare to a deep learning method. Results show that our method achieves the same performance as the deep learning method on open container classification and outperforms it on autonomous pouring. Moreover, our method is fully explainable.

Accuracy Evaluation of a Three‐Dimensional Model Generated from Patient‐Specific Monocular Video Data for Maxillofacial Prosthetic Rehabilitation: A Pilot Study

To evaluate if the combination of a monoscopic photogrammetry technique and smartphone-recorded monocular video data could be appropriately applied to maxillofacial prosthesis fabrication. Smartphone video and laser scanning data were recorded for five healthy volunteers (24.1± 0.7 years). Three-dimensional (3D) facial models were generated using photogrammetry software and a laser scanner. Smartphone-recorded video data were used to generate a photogrammetric 3D model. The videos were recorded at two resolutions: 1080 × 1920 (high resolution) and 720 × 1280 pixels (low resolution). The lengths of five nasal component parts (nose height, nasal dorsum length, nasal column length, nasal ala length, and nose breadth) were compared in the photogrammetric 3D models (as the test model) and the laser scanned 3D models (as the validation model) using reverse engineering software. There was a significant difference in the nasal dorsum length between the test model and the validation model (high resolution; 95% confidence interval, 2.05-5.07, Low resolution; confidence interval, 2.19-5.69). In contrast to the nasal dorsum length, there were no significant differences in nose height, nose breadth, nasal ala length, and nasal column length. Using smartphone-recorded video data and a photogrammetry technique may be a promising technique to apply in the maxillofacial prosthetic rehabilitation workflow.

Influence of the geometry of the airways on the characterization of exhalation flows. Comparison between two different airway complexity levels performing two different breathing functions

Human exhalation can emit pathogens in droplets that can represent the origin of airborne cross infections. Simplified respiratory airway models have been used in experimental and numerical studies in order to simulate exhalation flows. This study presents a comparison between two different airway models, a simplification (SA) and a realistic 3D scanned model (RA) in performing two different exhalation patterns corresponding to two different female metabolic rates, corresponding to a standing relaxed (SR) activity (1.2 met) and walking active (WA) metabolic level (2 met). A time resolved particle image velocimetry (TR-PIV) study of the flow emitted to the surroundings in each case is obtained for each airway and exhalation combination. Results show that the scanned 3D model (RA) presents a different and more realistic flow development. Transient puff structures have been identified for both airway models. Results can be useful for further research on pollution control in indoor and outdoor spaces.

A cost-benefit analysis of 3D scanning technology for crime scene investigation

Properly and thoroughly documenting a crime scene is of utmost importance in solving a crime, yet the process is often difficult and labor intensive. 3D scanning technology allows for the rapid acquisition of highly detailed 3D models of a physical environment. In recent years, adoption of 3D scanning technology has increased amongst crime scene investigation (CSI) units across the world to aid in the investigative process. The technology allows investigators to analyze crime scenes at a later point in time with a scanned 3D model. Unfortunately, the adoption cost of this technology remains a detractor to many CSI units. The presented research seeks to better understand whether investing in this technology results in an overall benefit for CSI units, and if so, when and how? To answer these questions, the research team developed a formal cost-benefit analysis algorithm for 3D scanning technology adoption. Considerations of the algorithm were influenced by actual 3D scanning results of mock crime scenes, together with a focus group of crime scene investigators that discussed the technology. A 100,000 count Monte-Carlo simulation of the developed cost-benefit algorithm enabled researchers to seek an answer to the question of adoption. The results of the simulation are presented in this document as well as through an interactive web application.

Layer thickness estimation of 3D printed model for digital multimedia forensics

Layer thickness is the major parameter of the 3D printing process that should be investigated for digital forensic purposes. However, despite its importance, there have been no studies yet on this parameter of layer-manufactured models. This Letter focuses on an effective estimation of layer thickness parameters for layer-manufactured models. Based on the analysis results of the scanned 3D model, the proposed method provides a new solution for estimating the layer thickness. Regarding potential applications including multimedia forensics, the proposed estimator would be useful in a variety of fields.

Computer Tomography Based Structure Characterization of Expanded Intumescent Coatings for Fire Protection

Intumescent coatings are used to protect structural steel from fires. In this study, morphological characteristics of expanded and charred intumescent coatings, which is a key factor of its thermal insulating mechanisms, have been studied using a computer tomography (CT)-based analysis method. Specimens of the charred materials are prepared by a laboratory-scale mass-loss cone heating method for measuring thermal insulation performance. Three types of coatings are exposed to three constant incident heat fluxes (25 kW/m2, 50 kW/m2, and 75 kW/m2) for 2 h. The micro-CT scanning technology is applied on the charred materials to generate 3D reconstructed images with 20 µm resolution by ImageJ software. By using an image processing technique, the central region of each scanned 3D model is divided into three horizontal layers at different depths: top, middle and bottom. The morphological structure varies significantly with the type of coatings, the incident heat flux, and the depth in the char, but the median value of pore size (i.e. equivalent diameter) for all tested samples varies within a narrow range (0.352 mm to 0.424 mm). The qualitative morphological observations as well as the quantitative pore properties (i.e., 3D porosity, size distributions, and sphericity) are obtained. The present non-destructive structure analyses method is useful to assist in new formulation developments and to advance numerical modeling.

3D Technologies in the Production of Jewelry with Elements of Complicated Design

The article analyzes the objects of complicated shapes and technologies of their exact reproduction in jewelry which allow creating elements of complicated design at the stage of creation of master-models. The possibilities of applying 3D technologies are correlated with the sizes of objects that are complicated in design. The technologies allowing to most accurately convey the shape and texture of objects of complex shape - forming on a small-sized object with a complex design, using a ductile metallic mass and using a scanned 3D model of an object of a large shape with a complicated design - are considered in detail.

Mineral mapping by hyperspectral remote sensing in West Greenland using airborne, ship-based and terrestrial platforms

While multispectral images have been in regular use since the 1970s, the widespread use of hyperspectral images is a relatively recent trend. This technology comprises remote measurement of specific chemical and physical properties of surface materials through imaging spectroscopy. Regional geological mapping and mineral exploration are among the main applications that may benefit from hyperspectral technology. Minerals and rocks exhibit diagnostic spectral features throughout the electromagnetic spectrum that allow their chemical composition and relative abundance to be mapped. Most studies using hyperspectral data for geological applications have concerned areas with arid to semi-arid climates, and using airborne data collection. Other studies have investigated terrestrial outcrop sensing and integration with laser scanning 3D models in ranges of up to a few hundred metres, whereas less attention has been paid to ground-based imaging of more distant targets such as mountain ridges, cliffs or the walls of large pits. Here we investigate the potential of using such data in well-exposed Arctic regions with steep topography as part of regional geological mapping field campaigns, and to test how airborne hyperspectral data can be combined with similar data collected on the ground or from moving platforms such as a small ship. The region between the fjords Ikertoq and Kangerlussuaq (Søndre Strømfjord) in West Greenland was selected for a field study in the summer of 2016. This region is located in the southern part of the Palaeoproterozoic Nagssugtoqidian orogen and consists of high-grade metamorphic ortho- and paragneisses and metabasic rocks (see below). A regional airborne hyperspectral data set (i.e. HyMAP) was acquired here in 2002 (Tukiainen &amp; Thorning 2005), comprising 54 flight lines covering an area of c. 7500 km2; 19 of these flight lines were selected for the present study (Fig. 1). The target areas visited in the field were selected on the basis of preliminary interpretations of HyMap scenes and geology (Korstgård 1979). Two different sensors were utilised to acquire the new hyperspectral data, predominantly a Specim AisaFenix hyperspectral scanner due to its wide spectral range covering the visible to near infrared and shortwave infrared parts of the electromagnetic spectrum. A Rikola Hyperspectral Imager constituted a secondary imaging system. It is much smaller and lighter than the Fenix scanner, but is spectrally limited to the visible near infrared range. The results obtained from combining the airborne hyperspectral data and the Rikola instrument are presented in Salehi (2018), this volume. In addition, representative samples of the main rock types were collected for subsequent laboratory analysis. A parallel study was integrated with geological and 3D photogrammetric mapping in Karrat region farther north in West Greenland (Rosa et al. 2017; Fig. 1).

Validity and Reliability of Arch Size Measurements Using Laser Scanned 3D Model

Validity and Reliability of Arch Size Measurements Using Laser Scanned 3D Model

Area-based quality control of airborne laser scanning 3D models for different land classes using terrestrial laser scanning: sample survey in Houston, USA

Airborne laser scanning (ALS) is a remote-sensing technique that provides scale-accurate 3D models consisting of dense point clouds with x, y planimetric coordinates and altitude z. Using ALS, very high-resolution (VHR) digital surface models (DSMs) have been widely used for commercial and scientific applications since the early 1990s. Although there is widespread usage, there has been little comprehensive investigation of quality control for ALS DSMs in the literature, as most studies have been limited to assessing point-based vertical accuracy. This article is dedicated to investigating the quality of ALS DSMs for different land classes using statistical and visual approaches based on absolute and relative vertical accuracy metrics. Rather than a limited number of ground control points (GCP), the model-to-model-based approach is applied and DSMs derived from terrestrial laser scanning (TLS) point clouds that have around 5 mm absolute and 3 mm relative geolocation accuracy were used as the reference data for comparison. The results demonstrate that in open, grass, and building land classes, the ALS DSMs reached both standard deviation (σ) and normalized median absolute deviation (NMAD) of 3–5 cm after the elimination of any systematic biases. This result sufficiently satisfies the vertical accuracy requirements for 1/1000-scale topographic maps determined by National Digital Elevation Program (NDEP) specifications. In tall vegetation, a higher number of discrepancies larger than 0.5 m exist, reversing the relation between σ and NMAD. These vegetation errors also do not appear to be normally distributed. As an additional investigation, the performance of ALS DEMs under dense high-vegetation areas was assessed. These under-canopy ALS DEMs, created using only classified ground returns, offer both σ and NMAD of 12–14 cm, a performance level that is difficult to achieve under-canopy using photogrammetric techniques.