A Clustering-based Algorithm for Extracting the Centerlines of 2D and 3D Objects

2006 ◽  
Author(s):  
S. Ferchichi ◽  
Shengrui Wang
Keyword(s):  
3D Objects ◽  
2D And 3D

scholarly journals Voxelisation Algorithms and Data Structures: A Review

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8241
Author(s):  
Mitko Aleksandrov ◽  
Sisi Zlatanova ◽  
David J. Heslop
Keyword(s):  
Data Structure ◽  
Data Structures ◽  
State Of The Art ◽  
Algorithms And Data Structures ◽  
3D Objects ◽  
Digital Representations ◽  
Memory Footprint ◽  
Voxel Data ◽  
2D And 3D ◽  
Geometric Primitives

Voxel-based data structures, algorithms, frameworks, and interfaces have been used in computer graphics and many other applications for decades. There is a general necessity to seek adequate digital representations, such as voxels, that would secure unified data structures, multi-resolution options, robust validation procedures and flexible algorithms for different 3D tasks. In this review, we evaluate the most common properties and algorithms for voxelisation of 2D and 3D objects. Thus, many voxelisation algorithms and their characteristics are presented targeting points, lines, triangles, surfaces and solids as geometric primitives. For lines, we identify three groups of algorithms, where the first two achieve different voxelisation connectivity, while the third one presents voxelisation of curves. We can say that surface voxelisation is a more desired voxelisation type compared to solid voxelisation, as it can be achieved faster and requires less memory if voxels are stored in a sparse way. At the same time, we evaluate in the paper the available voxel data structures. We split all data structures into static and dynamic grids considering the frequency to update a data structure. Static grids are dominated by SVO-based data structures focusing on memory footprint reduction and attributes preservation, where SVDAG and SSVDAG are the most advanced methods. The state-of-the-art dynamic voxel data structure is NanoVDB which is superior to the rest in terms of speed as well as support for out-of-core processing and data management, which is the key to handling large dynamically changing scenes. Overall, we can say that this is the first review evaluating the available voxelisation algorithms for different geometric primitives as well as voxel data structures.

Patterned 2D and 3D Assemblies of Nanoparticles on Molecular Printboards

2006 ◽  
Vol 51 ◽  
pp. 105-114 ◽  
Author(s):  
Jurriaan Huskens
Keyword(s):  
Silica Nanoparticles ◽  
Nanoimprint Lithography ◽  
Three Dimensions ◽  
Host Recognition ◽  
Self Assembled Monolayers ◽  
Layer By Layer ◽  
3D Objects ◽  
Lbl Assembly ◽  
Assembled Monolayers ◽  
2D And 3D

Functionalized nanoparticles have powerful applications as intermediates between solution and surface chemistry and as tools for nanofabrication. Two main examples of these have been shown. The functionalization of 3 nm gold and 55 nm silica nanoparticles with cyclodextrin (CD) host sites has been achieved, which allows: (i) the controlled aggregation with guestfunctionalized dendrimers in solution, (ii) the specific adsorption onto dendrimer-patterned substrates, and (iii) the fabrication of larger architectures using the layer-by-layer methodology. Aggregation in solution was shown to proceed through specific host-guest recognition. The adsorption onto surfaces employed so-called “molecular printboards”, which are self-assembled monolayers with the same cyclodextrin host recognition sites which allow the stable assembly of molecules and nanoparticles through multivalent host-guest interactions. CD silica nanoparticles were shown to adsorb specifically onto areas of such molecular printboards which were patterned with adamantyl-functionalized dendrimers. The layer-by-layer (LBL) assembly of such dendrimers and CD gold nanoparticles led to a controllable multilayer architecture with a thickness increase of about 2 nm per bilayer. The combination of the (bottom-up) particle LBL assembly and top-down surface structuring, in particular nanoimprint lithography, was shown to result in the formation of 3D objects down to sub-100 nm in all three dimensions.

scholarly journals PROVIDING ADITTIONAL COTENT TO PRINT MEDIA USING AUGMENTED REALITY

2018 ◽  
pp. 180-189
Author(s):  
Julien Letellier ◽  
Jens Reinhardt ◽  
Peter Scholl ◽  
Jürgen Sieck ◽  
Michael Thiele-Maas
Keyword(s):  
Augmented Reality ◽  
High Performance ◽  
Interactive Media ◽  
Handheld Devices ◽  
Joint Project ◽  
3D Objects ◽  
Printed Media ◽  
Audio Video ◽  
Start Ups ◽  
2D And 3D

While not a new concept, Augmented Reality (AR) has gained increasing momentum in the last few years through the widespread propagation of high-performance mobile devices. These powerful handheld devices allow users to see the real world enhanced with computer-generated content anywhere at anytime. This has led to a massive rise of AR technology; large companies and start-ups are adding affordable AR accessories to their product portfolios. In this paper we describe a joint project between our research group and the Konzerthaus Berlin to use AR to enrich the Konzerthaus’ printed media. With the aid of AR, the readers of the seasonal brochure of the Konzerthaus Berlin are given the opportunity to access additional content complementing the brochure. These contents include images, illustrations, audio, video, simple 2D and 3D animations, interactive media as well as 3D objects. The application was implemented using Vuforia and Unity. This is an extended version of the paper presented at the Conference on Culture and Computer Science 2017 [17].

Interface-Based Differences in Online Decision Making

2009 ◽  
pp. 769-775
Author(s):  
David Mazursky
Keyword(s):  
Decision Making ◽  
Web Sites ◽  
Web Site ◽  
3D Objects ◽  
Unique Experience ◽  
Pros And Cons ◽  
Online Decision Making ◽  
2D And 3D ◽  
Online Web ◽  
Site Managers

In recent years the online Web site interface format was found to have significant effects on attitudes toward the store and people’s actual experiences when visiting Web sites. In attempting to gain a competitive advantage, online site managers are adopting state-of-the-art technologies, aiming to create a unique experience and to capture more of people’s attention during their navigation. Using 3D technology interface gives site designers the opportunity to create a total experience. They are generally used in two formats. The first, more common format, is adopted for displaying 3D objects within a 2D interface site, and characterizes today’s numerous Web site stores (Nantel, 2004). The second format, which is still rare, is for creation of virtual reality environments (Figure 1). Converting a 2D interface site to a 3D interface site requires both technological investment, and gaining user confidence in the new environment. Therefore, site managers must weigh the pros and cons of each method before performing the conversion. The current analysis compares 2D and 3D interfaces, pointing out the advantages and shortcomings of each format.

Aesthetic Curves and Surfaces in Computer Aided Geometric Design

2014 ◽  
Vol 8 (3) ◽  
pp. 304-316 ◽  
Author(s):  
Kenjiro T. Miura ◽  
◽  
R. U. Gobithaasan ◽  
Keyword(s):  
Free Form ◽  
Design Quality ◽  
Aesthetic Design ◽  
3D Objects ◽  
Curves And Surfaces ◽  
Viable Solution ◽  
Main Components ◽  
2D And 3D ◽  
Free Form Surfaces ◽  
Complex Curvature

Aesthetic shapes are usually actualized as 3D objects represented by free-form surfaces. The main components used to achieve aesthetic surfaces are 2D and 3D curves, which are the elements most basic for determining the shapes and silhouettes of industrial products. Bézier, B-Spline and NURBS are types of flexible curves developed for various design intents. These curves, however produce complex curvature functions that may undermine the formulation of shape aesthetics. A viable solution to this problem is to formulate aesthetic curves and surfaces from well-defined curvatures to improve aesthetic design quality. This paper advocates formalizing aesthetic curve and surface theories to fill the gapmentioned above, which has existed since the 1970s. This paper begins by reviewing on fair curves and surfaces. It then extensively discusses on the technicalities of Log-Aesthetic (LA) curves and surfaces and touches on industrial design applications. These emerging LA curves have a high potential for being used as standards to generate, evaluate and reshape aesthetic curves and surfaces, thus revolutionizing efficiency in developing curve and shape aesthetics.

scholarly journals Virtual ground truth, and pre-selection of 3D interest points for improved repeatability evaluation of 2D detectors

2019 ◽  
Vol 277 ◽  
pp. 02032
Author(s):  
Simon R Lang ◽  
Martin H Luerssen ◽  
David M Powers
Keyword(s):  
Ground Truth ◽  
Virtual Space ◽  
Interest Points ◽  
3D Objects ◽  
3D Environments ◽  
Simple Features ◽  
Affine Transforms ◽  
2D And 3D ◽  
Selection Of

In Computer Vision, finding simple features is performed using classifiers called interest point (IP) detectors, which are often utilised to track features as the scene changes. For 2D based classifiers it has been intuitive to measure repeated point reliability using 2D metrics given the difficulty to establish ground truth beyond 2D. The aim is to bridge the gap between 2D classifiers and 3D environments, and improve performance analysis of 2D IP classification on 3D objects. This paper builds on existing work with 3D scanned and artificial models to test conventional 2D feature detectors with the assistance of virtualised 3D scenes. Virtual space depth is leveraged in tests to perform pre-selection of closest repeatable points in both 2D and 3D contexts before repeatability is measured. This more reliable ground truth is used to analyse testing configurations with a singular and 12 model dataset across affine transforms in x, y and z rotation, as well as x, y scaling with 9 well known IP detectors. The virtual scene's ground truth demonstrates that 3D preselection eliminates a large portion of false positives that are normally considered repeated in 2D configurations. The results indicate that 3D virtual environments can provide assistance in comparing the performance of conventional detectors when extending their applications to 3D environments, and can result in better classification of features when testing prospective classifiers' performance. A ROC based informedness measure also highlights tradeoffs in 2D/3D performance compared to conventional repeatability measures.

Geometric soft hash functions for 2D and 3D objects

2004 ◽  
Author(s):  
Emmanuel Fernandes ◽  
Jean-Francois Delaigle
Keyword(s):  
Hash Functions ◽  
3D Objects ◽  
2D And 3D

scholarly journals Formation of 2D and 3D multi-tori mesostructures via crystallization-driven self-assembly

2020 ◽  
Vol 6 (16) ◽  
pp. eaaz7301
Author(s):  
Gerald Guerin ◽  
Menandro Cruz ◽  
Qing Yu
Keyword(s):  
Self Assembly ◽  
Mixed Solvents ◽  
Three Dimensional ◽  
Solvent Mixture ◽  
Second Step ◽  
Spherical Shells ◽  
Topological Constraints ◽  
3D Objects ◽  
Multistep Process ◽  
2D And 3D

The fabrication of three-dimensional (3D) objects by polymer self-assembly in solution is extremely challenging. Here, multi-tori mesostructures were obtained from the crystallization-driven self-assembly of a coil-crystalline block copolymer (BCP) in mixed solvents. The formation of these structures follows a multistep process. First, the BCP self-assembles into amorphous micrometer-large vesicles. Then, the BCP confined in these mesosized vesicles crystallizes. This second step leads to the formation of objects with shapes ranging from closed 3D multi-tori spherical shells to 2D toroid mesh monolayers, depending on the solvent mixture composition. This approach demonstrates how topological constraints induced by the specific interactions between coil-crystalline BCP and solvents can be used to prepare mesostructures of complex morphologies.

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