3D Scanning Technology Research Articles

Customized Orthosis Design Based on Surface Reconstruction from 3D-Scanned Points

Limb disability is a frequent healthcare problem, especially for patients in primary care. Orthotic treatment has become the most common practice for either rehabilitation or permanent assistance, due to the emergence of 3D scanning and 3D printing technologies. A CAD model rebuilt from captured data is a key step in the rapid prototyping process of customized orthoses. An accurate and robust surface reconstruction technique remains a research challenge, aiming for a well-fitting design and the patient’s comfort. Thus, this paper presents of a new 3D curve-based reconstruction algorithm to obtain a precise 3D surface of an orthotic device from a scanned body part. Numerical experiments of two orthosis design case studies are shown to evaluate the reliability and accuracy of the proposed approach compared to other reconstruction methods.

The effect of bra design on wearing appearance

PurposeEsthetic trend changes with the development of society and cultural differences. A minimizer bra designed to make breasts appear smaller is now popular with large-breasted women in China. To conform to the requirements of modern aesthetics in China, this paper aims to investigate vital features of breast appearance that influence people’s subjective evaluation of breast size and analyze how bra design parameters affect breast shape and make breasts appear smaller.Design/methodology/approachThis study used 3D scanning technology and reverse engineering software to obtain objective breast measurements in detail. A subjective evaluation experiment was conducted to evaluate the overall performance of seven minimizer bras compared to a basic comparison bra. Around 20 design parameters of 8 sample bras were identified to make a further study about the correlation between bra design features and breast shaping effect. To gain a deeper understanding of how bras interact with breast tissue, this study presented heat maps of the breast surface to visualize the deformation of breast shape.FindingsNine breasts' characteristics, such as the distance between bust points, breast depth, outer breast curvature and slope, etc. have been determined to be highly correlated with the visual reduction effect of breasts. In addition, for the bras in this experiment, the high-performance bra for women with large breasts tends to have a wider side panel, a wider under band, higher gore and a stronger transverse rigidity of the bra cup. According to the observation of heat maps of the breast surface, soft full-figure bras provide a wider range of compression to the breasts and effectively flatten the breasts.Originality/valueThis paper first aimed at the need to shape the ideal breast appearance for large-breasted women and make a further study of several hot-selling minimizer bras in China. The suggestions given in this paper help lingerie manufacturers better understand how design features of bras can affect their shaping effect and improve the wearing effect of minimizer bras for large-breasted women.

Functional Analysis of psychological healing based on 3D omni-directional scanning method to simulate the design of natural textured fabrics

Abstract This paper is centered on applying 3D omnidirectional scanning technology to design natural textured fabrics to explore its functionality in psychological healing. The therapeutic potential of fabric art has been widely recognized due to the prevalence of psychological stress in modern society. This study uses 3D omnidirectional scanning technology to scan knitted textures, optimize fabric texture models, and conduct experimental research and material development using elevation and lighting angles. The size, Angle, color, and other factors that affect the experiment of knitted materials were tested, and eight convenient materials were selected for psychological experiments. A two-week experiment was conducted to record and analyze changes in the psychological state of 30 subjects (15 men and 15 women). It was obtained that the intervention group using simulated fabrics decreased from an average of 38.14 to 27.25 in the level of mental awareness, which was significantly higher than the control group (p<0.01). In terms of mental health indicators, the intervention group showed significant improvement in depression, anxiety, and other dimensions. Using 3D omnidirectional scanning technology to simulate natural texture fabric design positively enhances mental awareness and improves mental health, which has a promising potential for psychological healing.

Exploring a digital technology framework for building rural security transformation

The safety of the original old buildings in the upgrading and remodeling of traditional rural landscape has become a key aspect that cannot be ignored. In particular, the age-old traditional buildings belong to the typical master and apprentice inheritance system of construction mode, there is no remaining architectural archives, architectural information is unclear, especially the hidden genes, it is difficult to comprehensively control the rural landscape transformation, and there is an urgent need for an effective technical means to support. By applying 3D scanning and BIM technology, engineers and technicians are able to efficiently obtain the relevant information of traditional village landscape, discover potential safety risks in advance, and take timely measures. The practice has an important application prospect in village landscape upgrading and reconstruction. The combination of 3D scanning and BIM technology in “safety renovation” can improve the level and effect of the renovation, and provide strong technical support for the smooth implementation of the traditional rural landscape upgrading and renovation.

Conservation Study of Hakka Architecture Nanyuan Shidi Wailong House

In Chinese traditional culture, the Hakka spirit embedded in traditional Hakka buildings occupies an extremely important position, and if the protection method is not appropriate, it will damage the typical buildings inherited by the Hakka for centuries, which is not conducive to the cultural inheritance of the Hakka. Traditional restoration methods are difficult to accurately and completely restore the original buildings due to reasons such as low efficiency, aging equipment and thus inability to achieve the expected restoration results. Based on the point cloud data obtained from CAD processing by 3D scanning technology, a comprehensive 3D building model information is established to form a building structure database, which is helpful for the formation of the Hakka traditional building database.

Advanced surface roughness characterization using 3D scanning technologies and YOLOv4

In modern manufacturing, providing high-quality surface finishes to mechanical parts is critical to maintaining product integrity and optimizing the performance of mechanical systems. Surface roughness directly affects various aspects of part functionality, including friction, wear resistance, and overall durability. Therefore, accurate and efficient assessment of surface finish quality is of paramount importance to ensure the reliability and longevity of mechanical components. To meet this need, this study proposes an intelligent system that leverages the capabilities of deep learning and computer vision technologies to estimate the surface roughness of machined steel parts. By combining these advanced techniques, manufacturers can automate and improve the surface quality inspection process, resulting in increased productivity and reduced costs associated with manual inspection methods. This paper proposes an innovative method for determining surface roughness after machining by combining 3D scanning technologies with the deep learning algorithm YOLOv4.

Recent methods of visualization used in the diagnosis and consolidation of historic structures

The subject addresses heritage objects that are subject to degradation processes caused by both natural and anthropogenic factors. One of the current solutions is directed towards a varied range of scientific instruments, thus facilitating the analysis and diagnosis of the concerned buildings, contributing also to the identification of materials and techniques used and providing information about any previous interventions of conservation attempts. Recent visualization methods used in the diagnosis and consolidation of historic structures can utilize both three-dimensional laser scanning technology and laser interferometry as a diagnostic method, as well as alternative methods such electrometry, magnetometry and ground penetrating radar devices. The subject aims to address how heritage objects can be secured using 3D scanning technologies. The case studies were conducted on the Bezdin Monastery Complex, the ”Saint Martyr Gheorghe” Church, the ”Saint Martyr Filimon” Monastery and the former Metropolitan Summer Residence in Sibiu. The selected case studies illustrate the methodology for obtaining and processing field data, as well as the use of this data in the diagnosis process and in selecting appropriate consolidation options for these historical structures based on obtained results. These technologies have provided specialists with the possibility of extracting vital information both in the diagnostic phase and throughout the implementation of restoration works. Advanced scanning technologies of today have enabled the creation of a database with the capability of providing pertinent information about a building’s past, starting from its initial stage, up to the completion of execution works, which significantly aids in facilitating the process of diagnostic analysis and structural calculation.

A Systematic Review on Rigid Exoskeleton Robot Design for Wearing Comfort: Joint Self-Alignment, Attachment Interface, and Structure Customization.

Exoskeleton robots enable individuals with impaired physical functions to perform daily activities and maintain independence. However, the discomfort experienced by users when using these devices may limit the application scope of exoskeleton robots. Therefore, this paper systematically defines and analyzes the key design factors affecting the wearing comfort of rigid exoskeleton robots by differentiating and discussing the characteristics of traditional exoskeleton robots and exoskeleton robots equipped with the self-alignment mechanism based on addressing misalignment issues. Furthermore, the various structural configurations of the Physical Human-Robot Attachment Interface (PHRAI) and related quantitative evaluation indicators are explored in depth, and the advantages and limitations of structural customized design methods combining parametric design, Three-Dimensional (3D) scanning, and 3D printing technology are evaluated. Finally, the current concerns in the research field and potential solution strategies are proposed, aiming to provide directional guidance to optimize future exoskeleton robots. The research findings are of significant value for enhancing the comfort of wearing exoskeleton robots and provide valuable theoretical and practical references for future research.

Research on the evolution of aggregate skeleton characteristics of asphalt mixture under uniaxial compression loading

The aggregate skeleton is the intrinsic core of asphalt mixtures for load transfer, which is quite different under various gradations. For evaluating the loading characteristics of the aggregate skeleton, this research combined the 3D blue-ray scanning technology and discrete element method (DEM) to establish the numerical models of different graded asphalt mixtures considering the real aggregate morphology. A linear parallel bond model was used to simulate the adhesion effect of asphalt, and the uniaxial compression numerical simulation was verified by indoor tests. In addition, the contact force, contact number, anisotropy, and rotation angle were used to evaluate the aggregate skeleton evolution under uniaxial compression loading. Furthermore, the contribution of each grade aggregate in the gradation to the skeleton structure was analyzed. Results show that the average contact force is higher in large-size aggregates above 9.5 mm, which exhibit greater load transfer efficiency. Moreover, 4.75–9.5 mm size aggregates combine the functions of bearing and filling, and its role is significantly affected by the gradation. It is also found that the internal skeleton structure can be optimized and adjusted under stress. The contact numbers of different graded mixtures follow a close decrease, and the strong contacts are mostly provided by coarse aggregates above 4.75 mm. The anisotropy development of aggregate skeleton contact force is induced by the stress, and the deviator fabric of asphalt mixtures show a good linear positive correlation with the uniaxial compressive strength (UCS). Besides, fine aggregates exhibit greater cumulative rotation angle and instability effect, it is feasible to detect asphalt mixture deformation by the rotation angle of particles.

Simulation-based thermal analysis and validation of clothed thermal manikin

Human thermal comfort within various environmental conditions is of paramount importance in a wide range of industries, including clothing design, indoor climate control, and occupational safety. Researchers are always in search the sophisticated tools and techniques that simulate the thermal regulation of human body under different environmental conditions. The present research aims to present a precise methodology for the simulation of clothed thermal manikin in controlled environmental conditions. A comprehensive method is recommended that consists of the use of 3D body scanning technology, different 2D and 3D CAD as well as thermal simulation software. The results of the simulations are very satisfactory, which are later validated with the wear trials with the help of the same clothed thermal manikin and under the same environmental conditions. The comparative analysis shows some deviations that are discussed thoroughly and the need for further research is highlighted in the papers as well. Furthermore, the present research gives us a digital platform to understand the clothing's thermal comfort and the parameters that affect it with the consideration of the draping behavior of the clothing, microclimate, thermal properties, and surrounding environmental conditions.

Correlation between spatial characteristics and overflow rate of back alleys in high‐density city of Hong Kong

AbstractIn recent years, scholarly attention has shifted within urban informality research from informal settlements to the appropriation of public spaces in formal urban settings. Overflow, a common research subject within this context, has drawn particular interest. This study investigates overflow dynamics in a representative district of Hong Kong, utilizing the overflow rate as a measure of the extent to which overflow occurs. Three‐dimensional (3D) scanning technology was applied to collect spatial data from back alleys. Multiple linear regression analyses were conducted to identify the spatial characteristics of back alleys that influence overflow rates. The results revealed that back alleys with a flatter spatial interface, more overhead shelter, greater numbers of alley‐shops, and shorter overall length corresponded to a higher number of overflow occurrences. Two novel findings emerged: First, a negative correlation between spatial interface unevenness and overflow rates, and second, differential impacts of the shop density and number of alley‐shops on overflow rates. These findings may serve as a valuable reference for governmental policy formulation regarding overflow management and may offer architects workable insights for designing back alleys and street spaces conducive to public use.

A Framework Study on the Application of AIGC Technology in the Digital Reconstruction of Cultural Heritage

Abstract AIGC is currently a hot field and a future trend in AI applications, and addressing the challenge of digitally reconstructing cultural heritage under the influence of AI technology is a pressing issue that requires immediate resolution. The article proposes an application framework for AIGC technology that is based on refining its meaning and designing a specific process for applying it to the digital reconstruction of cultural heritage. A high-definition camera is used to acquire relevant images of cultural heritage. The image features are extracted by the SIFT algorithm optimized by the PROSAC algorithm. The color features are acquired by combining the color histogram, color moment, and color correlation diagram. The 3D laser scanning technology is used to obtain the 3D point cloud data of the cultural heritage; the KD-tree improved ICP algorithm is introduced to improve the efficiency of point cloud alignment; the dense reconstruction of the 3D point cloud data of the cultural heritage is realized based on CMVS/PMVS; and the immersive 3D experience system of the cultural heritage is constructed by combining with platforms such as Unity3D. The average matching rate of the optimized SITF algorithm to the image features of cultural heritage is about 74.91%, and the maximum alignment time of the ICP algorithm to the cultural heritage point cloud data based on KD-tree is 9.241 s. The cultural heritage immersive 3D experience system has a satisfaction rate of 56.75%, and the density reconstructed model’s surface has an average deviation of only 0.34 mm from the real surface. The user satisfaction rating for the immersive 3D experience system for cultural heritage is 56.75%. Based on AIGC technology, it can revitalize cultural heritage and achieve digital reconstruction and inheritance innovation of cultural heritage.

A Novel SMFL‐Based Assessment Method for Corrosion Nonuniformity of Rebar and Its Application in Reliability Analysis of Corroded RC Beam

The reliability of corroded reinforced concrete (RC) structures relies on the accurate minimum cross‐sectional area of corroded rebar. In this study, the accurate morphologies and self‐magnetic flux leakage (SMFL) field strengths of twenty‐eight non‐uniformly corroded rebars were obtained using 3D structural light scanning and micromagnetic detection technologies, based on which three indices of the SMFL field variation ratio dH, the corrosion non‐uniformity degree dSn, and the cross‐sectional area ratio K0.25 are proposed. The statistical results show that the probability densities of dSn and K0.25 obey the Weibull distribution and Gamma distribution at the 95% confidence level, respectively, and their distribution parameters are linearly or inversely proportional to dH. The probability density distribution of the minimum cross‐sectional area of corroded rebar can be determined using indices dSn and K0.25, based on which a feasible SMFL‐based reliability assessment method of corroded RC structures is proposed. The case study of a real specific corroded RC beam shows that the reliability assessment error of the SMFL‐based method is only 1.2%, which is much lower than the 20.7% error of the existing method. This SMFL‐based method provides a novel idea that can automatically and accurately assess the effect of rebars’ corrosion non‐uniformity on the reliability of specific in‐serviceRC structures.

Optimization of Land Area Mapping and Volume Calculations using Drone Lidar Livox Mid-40 Data with the Downsampling Method

One reason for the growing acceptance of 3D point cloud-based research and applications is the quick advancement of 3D scanning technologies. However, there are still a number of serious issues that have an impact on point cloud utilization performance. Among these difficulties are controlling the quantity of points, irregular point density, and a deficiency of location proximity data. In this study, we use Livox Mid-40 Drone Lidar Data and a downsampling technique to compute land area and volume. However, it can be highly challenging and time-consuming to extract usable information from enormous amounts of gathered data. Motivated by these results, this study recommends using downsampling approaches to minimize the size of the final data set while preserving data integrity, which will facilitate and expedite. The Livox Mid-40 Lidar Drone data was optimal at 00:00:30 with a flying height of 75,719 meters and a measurement diameter of 50.3 meters. By using downsampling techniques, the number of points can be reduced by up to 40 percent from the previous number of data points. Meanwhile, the data size can be 10 percent smaller than the original data. To calculate the area of land of the same size, there is a difference of 0.53 square meters. Meanwhile, for the calculation of cubic volume, there is a difference of 1.63 cubic meters.

Digital technologies as a tool for identification the authorship of sacred sculpture

Latvian sculptures created before the mid-19th century are located mainly in churches, not in museum collections. The most serious obstacle to research of Latvian art in the given period is lack of pertinent documentary material. As a result, Latvian art historians have mostly studied the sculptures for which written sources are available. This article will offer solutions for further research in cases when written sources are limited or altogether unavailable. How much and what can be discovered using digitisation solutions? The study of the sculptures of the Biķernieki Church in Riga provides a paradigmatic case for further research with the help of digitisation. In 1967, when the congregation of the Biķernieki Church was forced to abandon the church, the sculptures were transferred to museums. Today they can be seen in the exhibition of the Rundāle Palace Museum. The scant extant documentary evidence does not allow us to establish the authorship of the sculptures or the time of their creation with certainty. The study discussed in the article shows the importance of digitisation in art history research. The current research is based on 3D models of the sculptures of the Biķernieki Church obtained using 3D scanning technology. Supplementing them with high-resolution photographs and other digital solutions can confirm or, on the contrary, refute assumptions about their authorship and creation made by historians so far. The article outlines the methods used to identify stylistic influences on the sculptures of the Biķernieki Church, suggesting that they may have been modelled after similar sculptures in Gdańsk (Danzig) and Dresden and even after certain antique sculptures. The graphic methods used in the research have made it possible to precisely identify the style of execution of a single sculptor in several churches in Riga.

COMPUTATIONAL WEARABLES DESIGN: SHOE SOLE MODELING AND PROTOTYPING

Computational wearables design is based on the integration of algorithms into the design process. The use of computational design tools offers a series of advantages in the wearable product design modelling because a complete family of products can be produced with a limited effort from the designer, while at the same time geometries with high complexity can be dealt with a manageable way. The present paper aims to create the appropriate code for modelling shoe soles. The use of a visual programming language leads to a better understanding of the produced code and aims in controlling and optimising the output models. Following the proposed methodology, 3D scanning technologies and plantar pressure diagrams are used for introducing the sole customised geometry, and then the proposed algorithm creates a variety of alternatives of the final shoe sole geometry. As a result, both the customisation and the high number of alternative designs lead to increased creativity and customer satisfaction. Due to the complexity of the geometry produced, 3D printing technologies are incorporated for the prototype implementation.

Study on the Digital Reassembly of Yoni Monument Excavated from Cella of Hong Nang Sida, Lao PDR

During the dismantling of the cella of the Hong Nang Sida temple in Laos, 100 highly significant Yoni-monument members were recovered as fragmented individual stones. To restore the Hong Nang Sida temple to its former glory, it is necessary to restore the fragmented Yoni-monument members to their original positions. However, the high weight and low mobility of the stones make it difficult to physically reassemble the story members. Therefore, this study utilized three-dimensional (3D) scanning, modeling, and printing technologies to digitally reassemble the Yoni monument. To achieve this goal, optimization modeling was performed to connect the three-dimensional (3D) scanning data of individual fragmented stones, after which each story member was reduced to a 1/5 of its original size and printed by sand printing to evaluate the feasibility of physical assembly. Finally, 3D scans of the Yoni monument assembled using the sand-printing outputs were taken, and all the story members were virtually aligned based on the scan data to complete the digital reassembly. We believe that the results of this study will improve the feasibility and completeness of the physical reassembly by allowing for a full preliminary examination of stone blocks, which would otherwise be difficult to achieve because of the risk of secondary damage or weight limitation. In particular, it is possible to objectively and visually illustrate the geometric relationship between the members of each story, which can be extended to similar stone-based cultural heritage sites. To broaden the utility of the digital-reassembly model, it must be evolved into a historic building information model that links the unstructured data, including documents, photos, and images, obtained throughout the process life cycle.

PointSGRADE: Sparse learning with graph representation for anomaly detection by using unstructured 3D point cloud data

Surface anomaly detection by using 3D point cloud data has recently received significant attention. To completely measure the common free-form surfaces without loss of details, advanced 3D scanning technologies, such as 3D laser scanners, can be applied and will produce an unstructured point cloud. However, this irregular data structure poses challenges to anomaly detection, in that the existing methods based on regular data, e.g., 2D image, cannot be directly applied. This article proposes a sparse learning framework with a graph representation of the unstructured point cloud for anomaly detection (PointSGRADE). Specifically, the free-form surface is assumed to be smooth. Then, the associated point cloud can be represented as a graph. Subsequently, considering the sparse anomalies, we propose a sparse learning framework and formulate the anomaly detection problem as a penalized optimization problem, which is further solved by a computationally efficient majorization-minimization framework. Case studies demonstrate the accuracy and robustness of the proposed method. This article proposes a novel methodology for sparse anomaly detection on smooth free-form surfaces represented by unstructured point cloud, which is critical for quality inspection in manufacturing and other application areas.

Optimising Amber Processing Using 3D Scanning: New Perspectives in Cultural Heritage

This article aims to present the practical and functional application of advanced 3D scanning technologies in the process of designing products made of amber. The processing of amber is complex and expensive because mass or serial production is not possible. Moreover, processing is challenging because each product is treated as unique and requires individual handling. The optimisation process is illustrated using the example of amber blocks that were scanned to obtain virtual 3D models. The scope of this work includes the characterisation of three-dimensional jewellery design processes, along with a description of a wide range of methods and functions used in computer-aided jewellery design. The use of computer-aided design software for developing virtual models of decorative products used in goldsmithing is described in this paper. The obtained sets of models underwent engineering analysis using Boolean algebra and data science calculations. In this way, a design methodology was developed regarding the selection of input material as the unprocessed stone for jewellery modelling. The developed method allows for the minimisation of material waste, which is associated with reducing costs in the processing of amber. This article also describes the differences between previous traditional methods and the authors’ proprietary method. The proposed methodology can be implemented in jewellery workshops specialising in the processing of materials.

Effect of roughness on shear behavior of interface between cemented paste backfill and rock

The interaction between cemented paste backfill (CPB) and rock at their interface plays a crucial role in the stability of underground backfill structures. Considering the interface roughness could have a significant influence on the shear behavior and mechanical properties of the interface, a series of laboratory direct shear tests were carried out on the CPB-rock interface with various roughnesses. The results indicates that the interface roughness and normal stresses have a remarkable effect on the interfacial shear behavior, with typical stress-shear displacement curves that could be classified into three types depending on the peak and post-peak characteristics. Compared to the smooth interface, the shear strength increases with increasing roughness, owing to the enhancing interlocking effect, which is confirmed by digital image correlation (DIC) in micro views. In addition, the shear contraction observed at the smooth interface changes to shear dilatation at the rough interface, which is caused by wider distribution and higher adhesion of CPB asperities, as observes by using 3D laser scanning technology. Furthermore, a theoretical model for the shear strength, taking into account the influence of interface roughness, is developed to assess its effect on shear strength. The experimental results and the theoretical model presented in this paper will contribute to better understand the interaction mechanism and predict the shear strength of the interface.