Three-Dimensional Measurement and Three-Dimensional Printing of Giant Coastal Rocks

In recent years, the use of three-dimensional (3D) measurement and printing technologies has become an effective means of analyzing and reproducing both physical and natural objects, regardless of size. However, in some complex environments, such as coastal environments, it is difficult to obtain the required data by conventional measurement methods. In this paper, we describe our efforts to archive and digitally reproduce a giant coastal rock formation known as Sanouiwa, a famous site off the coast of Miyako City, Iwate Prefecture, Japan. We used two different 3D measurement techniques. The first involved taking pictures using a drone-mounted camera, and the second involved the use of global navigation satellite system data. The point cloud data generated from the high-resolution camera images were integrated using 3D shape reconstruction software, and 3D digital models were created for use in tourism promotion and environmental protection awareness initiatives. Finally, we fabricated the 3D digital models of the rocks with 3D printers for use as museum exhibitions, school curriculum materials, and related applications.

Download Full-text

Algorithm for Generating 3D Geometric Representation Based on Indoor Point Cloud Data

Applied Sciences ◽

10.3390/app10228073 ◽

2020 ◽

Vol 10 (22) ◽

pp. 8073

Author(s):

Min Woo Ryu ◽

Sang Min Oh ◽

Min Ju Kim ◽

Hun Hee Cho ◽

Chang Baek Son ◽

...

Keyword(s):

Point Cloud ◽

Indoor Environment ◽

Three Dimensional ◽

Satellite System ◽

Normal Vector ◽

Geometric Representation ◽

Point Cloud Data ◽

Cloud Data ◽

Data Process ◽

Global Navigation Satellite

This study proposes a new method to generate a three-dimensional (3D) geometric representation of an indoor environment by refining and processing an indoor point cloud data (PCD) captured through backpack laser scanners. The proposed algorithm comprises two parts to generate the 3D geometric representation: data refinement and data processing. In the refinement section, the inputted indoor PCD are roughly segmented by applying random sample consensus (RANSAC) to raw data based on an estimated normal vector. Next, the 3D geometric representation is generated by calculating and separating tangent points on segmented PCD. This study proposes a robust algorithm that utilizes the topological feature of the indoor PCD created by a hierarchical data process. The algorithm minimizes the size and the uncertainty of raw PCD caused by the absence of a global navigation satellite system and equipment errors. The result of this study shows that the indoor environment can be converted into 3D geometric representation by applying the proposed algorithm to the indoor PCD.

Download Full-text

Three-Dimensional Measurement System Based on Micro Stereovision

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.609-610.1189 ◽

2014 ◽

Vol 609-610 ◽

pp. 1189-1194

Author(s):

Wei Pei ◽

Yong Ying Zhu ◽

S.X. Liu ◽

J.M. Wen

Keyword(s):

Nonlinear Model ◽

Stereo Vision ◽

Vision System ◽

Shape Reconstruction ◽

Coupling Mechanism ◽

3D Measurement ◽

Reconstruction Algorithms ◽

Micro Assembly ◽

Stereo Vision System ◽

3D Shape Reconstruction

With vision feedback the binocular micro stereovision system based on stereo light microscope (SLM) makes it possible to achieve 2D/3D high accuracy auto-positioning, 3D information extraction, 3D shape reconstruction and 3D measurement. Therefore, it is extensively used in micro robot navigation, micromanipulation, micro assembly and bioengineering, etc. To improve the key problems of low accuracy, refraction and occlusion in micro stereovision measurement, a novel micro stereo vision system is built based on optical theory and digital image processing. Then, the nonlinear correlation between optical paths of the micro stereo vision system is studied and the environment adaptive nonlinear model is established. On this basis, the coupling mechanism of multi-refraction and occlusion with micro-projection nonlinear model is proved, and multi-refraction variable refractive index correction and micro stereo occlusion reconstruction algorithms are developed. It realizes synchronization observation in larger field of view, rapid non-contact accuracy positioning and 3D measurement based on stereovision to solve the pivotal problems of accuracy positioning and measure in the chip encapsulation, micro assembly and the micro manipulation.

Download Full-text

Promoting a More Interactive Public Archaeology

Advances in Archaeological Practice ◽

10.7183/2326-3768.3.3.235 ◽

2015 ◽

Vol 3 (3) ◽

pp. 235-248 ◽

Cited By ~ 15

Author(s):

Bernard K. Means

Keyword(s):

Narrow Band ◽

Three Dimensional ◽

Laser Scanner ◽

Public Archaeology ◽

Archaeological Sites ◽

Digital Models ◽

The Past ◽

Fresh Perspective ◽

Virginia Commonwealth University ◽

3D Digital Models

AbstractStewards of the tangible past are increasingly embracing technologies that enable digital preservation of rare and fragile finds. The Virtual Curation Laboratory (VCL) at Virginia Commonwealth University (VCU) partners with museums, cultural heritage locations, and collections repositories to create three-dimensional (3D) digital models of artifacts from archaeological sites distributed across the globe. In the VCL, undergraduate VCU students bring a fresh perspective unburdened by archaeological orthodoxy as they use a laser scanner to record artifact details, edit the resulting digital models, and print plastic replicas that are painted to resemble the original items. The 3D digital models and printed replicas allow for new ways of visualizing the past, while preserving the actual artifacts themselves. These forms of archaeological visualization enable the broader public and not just a narrow band of researchers to dynamically and meaningfully interact with rare and fragile objects in ways that would otherwise not be possible, empowering their own contributions to interpreting, understanding, and reimagining the past. We must embrace co-creation through virtual artifact curation and recognize that, while we sacrifice some control over the stories that are told about the past, more stories will be told and shared as pieces of the past become more accessible.

Download Full-text

TRIANGULATION AND TIME-OF-FLIGHT BASED 3D DIGITISATION TECHNIQUES OF CULTURAL HERITAGE STRUCTURES

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xliii-b2-2021-825-2021 ◽

2021 ◽

Vol XLIII-B2-2021 ◽

pp. 825-830

Author(s):

C. Altuntas

Keyword(s):

Cultural Heritage ◽

Laser Scanning ◽

Low Cost ◽

Measurement Techniques ◽

Three Dimensional ◽

Laser Scanner ◽

Time Of Flight ◽

Cost Effective ◽

Cloud Data ◽

Dense Point

Abstract. This study aims to introduce triangulation and ToF measurement techniques used in three-dimensional modelling of cultural heritages. These measurement techniques are traditional photogrammetry, SfM approach, laser scanning and time-of-flight camera. The computer based approach to photogrammetric measurement that is named SfM creates dense point cloud data in a short time. It is low-cost and very easy to application. However traditional photogrammetry needs a huge effort for creating 3D wire-frame model. On the other hand active measurement techniques such as terrestrial laser scanner and time-of-flight camera have also been used in three-dimensional modelling for more than twenty years. Each one has specific accuracy and measurement effectiveness. The large or small structures have different characters, and require proper measurement configurations. In this study, after these methods are introduced, their superior and weak properties in cultural heritage modelling to make high accuracy, high density and labour and cost effective measurement.

Download Full-text

3D Object Shape Reconstruction from Underwater Multibeam Data and Over Ground Lidar Scanning

Polish Maritime Research ◽

10.2478/pomr-2018-0053 ◽

2018 ◽

Vol 25 (2) ◽

pp. 47-56 ◽

Cited By ~ 2

Author(s):

Marek Kulawiak ◽

Zbigniew Łubniewski

Keyword(s):

Laser Scanning ◽

Spatial Information ◽

Dimensional Space ◽

Three Dimensional ◽

Measurement Data ◽

Point Clouds ◽

Shape Reconstruction ◽

Reconstruction Algorithms ◽

Processing Scheme ◽

3D Shape Reconstruction

Abstract The technologies of sonar and laser scanning are an efficient and widely used source of spatial information with regards to underwater and over ground environment respectively. The measurement data are usually available in the form of groups of separate points located irregularly in three-dimensional space, known as point clouds. This data model has known disadvantages, therefore in many applications a different form of representation, i.e. 3D surfaces composed of edges and facets, is preferred with respect to the terrain or seabed surface relief as well as various objects shape. In the paper, the authors propose a new approach to 3D shape reconstruction from both multibeam and LiDAR measurements. It is based on a multiple-step and to some extent adaptive process, in which the chosen set and sequence of particular stages may depend on a current type and characteristic features of the processed data. The processing scheme includes: 1) pre-processing which may include noise reduction, rasterization and pre-classification, 2) detection and separation of objects for dedicated processing (e.g. steep walls, masts), and 3) surface reconstruction in 3D by point cloud triangulation and with the aid of several dedicated procedures. The benefits of using the proposed methods, including algorithms for detecting various features and improving the regularity of the data structure, are presented and discussed. Several different shape reconstruction algorithms were tested in combination with the proposed data processing methods and the strengths and weaknesses of each algorithm were highlighted.

Download Full-text

Digital Shape Reconstruction of a Micro-Sized Machining Tool Using Light-Field Microscopy

International Journal of Automation Technology ◽

10.20965/ijat.2016.p0172 ◽

2016 ◽

Vol 10 (2) ◽

pp. 172-178 ◽

Cited By ~ 5

Author(s):

Shin Usuki ◽

◽

Masaru Uno ◽

Kenjiro T. Miura ◽

◽

...

Keyword(s):

Light Field ◽

Three Dimensional ◽

Microlens Array ◽

Axial Direction ◽

Shape Reconstruction ◽

Reconstruction Method ◽

Actual Length ◽

3D Shape ◽

Depth Images ◽

3D Shape Reconstruction

In this paper, we propose a digital shape reconstruction method for micro-sized 3D (three-dimensional) objects based on the shape from silhouette (SFS) method that reconstructs the shape of a 3D model from silhouette images taken from multiple viewpoints. In the proposed method, images used in the SFS method are depth images acquired with a light-field microscope by digital refocusing (DR) of a stacked image along the axial direction. The DR can generate refocused images from an acquired image by an inverse ray tracing technique using a microlens array. Therefore, this technique provides fast image stacking with different focal planes. Our proposed method can reconstruct micro-sized object models including edges, convex shapes, and concave shapes on the surface of an object such as micro-sized defects so that damaged structures in the objects can be visualized. Firstly, we introduce the SFS method and the light-field microscope for 3D shape reconstruction that is required in the field of micro-sized manufacturing. Secondly, we show the developed experimental equipment for microscopic image acquisition. Depth calibration using a USAF1951 test target is carried out to convert relative value into actual length. Then 3D modeling techniques including image processing are implemented for digital shape reconstruction. Finally, 3D shape reconstruction results of micro-sized machining tools are shown and discussed.

Download Full-text

A Fast Mask Projection Stereolithography Process for Fabricating Digital Models in Minutes

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4007465 ◽

2012 ◽

Vol 134 (5) ◽

Cited By ~ 79

Author(s):

Yayue Pan ◽

Chi Zhou ◽

Yong Chen

Keyword(s):

High Speed ◽

Experimental Studies ◽

Three Dimensional ◽

Thin Layers ◽

Digital Models ◽

Projection System ◽

Order Of Magnitude ◽

Projection Stereolithography ◽

Direct Digital Manufacturing ◽

3D Digital Models

The purpose of this paper is to present a direct digital manufacturing (DDM) process that is an order of magnitude faster than other DDM processes that are currently available. The developed process is based on a mask-image-projection-based stereolithography (MIP-SL) process, in which a digital micromirror device (DMD) controls projection light to selectively cure liquid photopolymer resin. In order to achieve high-speed fabrication, we investigate the bottom-up projection system in the MIP-SL process. A two-way linear motion approach has been developed for the quick spreading of liquid resin into uniform thin layers. The system design and related settings for achieving a fabrication speed of a few seconds per layer are presented. Additionally, the hardware, software, and material setups for fabricating three-dimensional (3D) digital models are presented. Experimental studies using the developed testbed have been performed to verify the effectiveness and efficiency of the presented fast MIP-SL process. The test results illustrate that the newly developed process can build a moderately sized part within minutes instead of hours that are typically required.

Download Full-text

3D Printing of Human Microbiome Constituents to Understand Spatial Relationships & Shape Parameters in Bacteriology

The American Biology Teacher ◽

10.1525/abt.2021.83.3.188 ◽

2021 ◽

Vol 83 (3) ◽

pp. 188-190

Author(s):

Jacques Izard ◽

Teklu Kuru Gerbaba ◽

Shara R. P. Yumul

Keyword(s):

Computer Aided Design ◽

Three Dimensional ◽

Human Microbiome ◽

Digital Models ◽

Ecological Relationships ◽

Wide Range ◽

3D Printers ◽

Visuospatial Information ◽

Aided Design ◽

3D Digital Models

Effective laboratory and classroom demonstration of microbiome size and shape, diversity, and ecological relationships is hampered by a lack of high-resolution, easy-to-use, readily accessible physical or digital models for use in teaching. Three-dimensional (3D) representations are, overall, more effective in communicating visuospatial information, allowing for a better understanding of concepts not directly observable with the unaided eye. Published morphology descriptions and microscopy images were used as the basis for designing 3D digital models, scaled at 20,000×, using computer-aided design software (CAD) and generating printed models of bacteria on mass-market 3D printers. Sixteen models are presented, including rod-shaped, spiral, flask-like, vibroid, and filamentous bacteria as well as different arrangements of cocci. Identical model scaling enables direct comparison as well as design of a wide range of educational plans.

Download Full-text

Three-Dimensional Needle Steering Using Automated Breast Volume Scanner (ABVS)

Journal of Medical Robotics Research ◽

10.1142/s2424905x16400055 ◽

2016 ◽

Vol 01 (01) ◽

pp. 1640005 ◽

Cited By ~ 3

Author(s):

Momen Abayazid ◽

Pedro Moreira ◽

Navid Shahriari ◽

Anastasios Zompas ◽

Sarthak Misra

Keyword(s):

Soft Tissue ◽

Three Dimensional ◽

Reconstruction Algorithm ◽

Needle Insertion ◽

Steering System ◽

Shape Reconstruction ◽

Ultrasound Transducer ◽

Breast Volume ◽

Automated Breast Volume Scanner ◽

3D Shape Reconstruction

Robot-assisted and ultrasound-guided needle insertion systems assist in achieving high targeting accuracy for different applications. In this paper, we introduce the use of Automated Breast Volume Scanner (ABVS) for scanning different soft tissue phantoms. The ABVS is a commercial ultrasound transducer used for clinical breast scanning. A preoperative scan is performed for three-dimensional (3D) target localization and shape reconstruction. The ultrasound transducer is also adapted to be used for tracking the needle tip during steering toward the localized targets. The system uses the tracked needle tip position as a feedback to the needle control algorithm. The bevel-tipped flexible needle is steered under ABVS guidance toward a target while avoiding an obstacle embedded in soft tissue phantom. We present experimental results for 3D reconstruction of different convex and non-convex objects with different sizes. Mean Absolute Distance (MAD) and Dice’s coefficient methods are used to evaluate the 3D shape reconstruction algorithm. The results show that the mean MAD values are 0.30[Formula: see text][Formula: see text]0.13[Formula: see text]mm and 0.34[Formula: see text][Formula: see text]0.17[Formula: see text]mm for convex and non-convex shapes, respectively, while mean Dice values are 0.87[Formula: see text]0.06 (convex) and 0.85[Formula: see text]0.06 (non-convex). Three experimental cases are performed to validate the steering system. Mean targeting errors of 0.54[Formula: see text][Formula: see text]0.24, 1.50[Formula: see text][Formula: see text]0.82 and 1.82[Formula: see text][Formula: see text]0.40[Formula: see text]mm are obtained for steering in gelatin phantom, biological tissue and a human breast phantom, respectively. The achieved targeting errors suggest that our approach is sufficient for targeting lesions of 3[Formula: see text]mm radius that can be detected using clinical ultrasound imaging systems.

Download Full-text