Graphical ModelsPub Date : 2024-06-01Epub Date: 2024-03-18DOI: 10.1016/j.gmod.2024.101216
Qun-Ce Xu , Yong-Liang Yang , Bailin Deng
{"title":"Point cloud denoising using a generalized error metric","authors":"Qun-Ce Xu , Yong-Liang Yang , Bailin Deng","doi":"10.1016/j.gmod.2024.101216","DOIUrl":"10.1016/j.gmod.2024.101216","url":null,"abstract":"<div><p>Effective removal of noises from raw point clouds while preserving geometric features is the key challenge for point cloud denoising. To address this problem, we propose a novel method that jointly optimizes the point positions and normals. To preserve geometric features, our formulation uses a generalized robust error metric to enforce piecewise smoothness of the normal vector field as well as consistency between point positions and normals. By varying the parameter of the error metric, we gradually increase its non-convexity to guide the optimization towards a desirable solution. By combining alternating minimization with a majorization-minimization strategy, we develop a numerical solver for the optimization which guarantees convergence. The effectiveness of our method is demonstrated by extensive comparisons with previous works.</p></div>","PeriodicalId":55083,"journal":{"name":"Graphical Models","volume":"133 ","pages":"Article 101216"},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1524070324000043/pdfft?md5=48a1964c4abbec912ee9a17b6f0212cf&pid=1-s2.0-S1524070324000043-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140151694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphical ModelsPub Date : 2024-06-01Epub Date: 2024-05-30DOI: 10.1016/j.gmod.2024.101219
Peisheng Zhuo , Zitong He , Hongwei Lin
{"title":"Persistent geometry-topology descriptor for porous structure retrieval based on Heat Kernel Signature","authors":"Peisheng Zhuo , Zitong He , Hongwei Lin","doi":"10.1016/j.gmod.2024.101219","DOIUrl":"10.1016/j.gmod.2024.101219","url":null,"abstract":"<div><p>Porous structures are essential in a variety of fields such as materials science and chemistry. To retrieve porous materials efficiently, novel descriptors are required to quantify the geometric and topological features. In this paper, we present a novel framework to create a descriptor that incorporates both topological and geometric information of a porous structure. To capture geometric information, we keep track of the <span><math><mrow><mi>b</mi><mi>i</mi><mi>r</mi><mi>t</mi><mi>h</mi><mspace></mspace><mspace></mspace><mi>t</mi><mi>i</mi><mi>m</mi><mi>e</mi></mrow></math></span> and <span><math><mrow><mi>d</mi><mi>e</mi><mi>a</mi><mi>t</mi><mi>h</mi><mspace></mspace><mspace></mspace><mi>t</mi><mi>i</mi><mi>m</mi><mi>e</mi></mrow></math></span> of the <span><math><mrow><mi>p</mi><mi>e</mi><mi>r</mi><mi>s</mi><mi>i</mi><mi>s</mi><mi>t</mi><mi>e</mi><mi>n</mi><mi>t</mi><mspace></mspace><mi>f</mi><mi>e</mi><mi>a</mi><mi>t</mi><mi>u</mi><mi>r</mi><mi>e</mi></mrow></math></span>s of a real-valued function on the surface that evolves with a parameter. Then, we generate the corresponding <span><math><mrow><mi>p</mi><mi>e</mi><mi>r</mi><mi>s</mi><mi>i</mi><mi>s</mi><mi>t</mi><mi>e</mi><mi>n</mi><mi>t</mi><mspace></mspace><mspace></mspace><mi>f</mi><mi>e</mi><mi>a</mi><mi>t</mi><mi>u</mi><mi>r</mi><mi>e</mi><mspace></mspace><mspace></mspace><mi>d</mi><mi>i</mi><mi>a</mi><mi>g</mi><mi>r</mi><mi>a</mi><mi>m</mi></mrow></math></span> (<span><math><mrow><mi>D</mi><mi>g</mi><msub><mrow><mi>m</mi></mrow><mrow><mi>P</mi><mi>F</mi></mrow></msub></mrow></math></span>) and convert it into a vector called <span><math><mrow><mi>p</mi><mi>e</mi><mi>r</mi><mi>s</mi><mi>i</mi><mi>s</mi><mi>t</mi><mi>e</mi><mi>n</mi><mi>c</mi><mi>e</mi><mspace></mspace><mspace></mspace><mi>f</mi><mi>e</mi><mi>a</mi><mi>t</mi><mi>u</mi><mi>r</mi><mi>e</mi><mspace></mspace><mspace></mspace><mi>d</mi><mi>e</mi><mi>s</mi><mi>c</mi><mi>r</mi><mi>i</mi><mi>p</mi><mi>t</mi><mi>o</mi><mi>r</mi></mrow></math></span> (PFD). To extract topological information, we sample points from the pore surface and compute the corresponding persistence diagram, which is then transformed into the Persistence B-Spline Grids (PBSG). Our proposed descriptor, namely <span><math><mrow><mi>p</mi><mi>e</mi><mi>r</mi><mi>s</mi><mi>i</mi><mi>s</mi><mi>t</mi><mi>e</mi><mi>n</mi><mi>t</mi><mspace></mspace><mspace></mspace><mi>g</mi><mi>e</mi><mi>o</mi><mi>m</mi><mi>e</mi><mi>t</mi><mi>r</mi><mi>y</mi><mo>−</mo><mi>t</mi><mi>o</mi><mi>p</mi><mi>o</mi><mi>l</mi><mi>o</mi><mi>g</mi><mi>y</mi><mspace></mspace><mspace></mspace><mi>d</mi><mi>e</mi><mi>s</mi><mi>c</mi><mi>r</mi><mi>i</mi><mi>p</mi><mi>t</mi><mi>o</mi><mi>r</mi></mrow></math></span> (PGTD), is obtained by concatenating PFD with PBSG. In our experiments, we use the heat kernel signature (HKS) as the real-valued function to compute the descriptor. We test the method on a synthetic porous dataset and a zeolite dataset and find that it is competitive compa","PeriodicalId":55083,"journal":{"name":"Graphical Models","volume":"133 ","pages":"Article 101219"},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1524070324000079/pdfft?md5=499cdacea6ff6d72e1f6c905040f66c2&pid=1-s2.0-S1524070324000079-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141232284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphical ModelsPub Date : 2024-06-01Epub Date: 2024-02-28DOI: 10.1016/j.gmod.2024.101214
Bowen Lyu , Li-Yong Shen , Chun-Ming Yuan
{"title":"IGF-Fit: Implicit gradient field fitting for point cloud normal estimation","authors":"Bowen Lyu , Li-Yong Shen , Chun-Ming Yuan","doi":"10.1016/j.gmod.2024.101214","DOIUrl":"https://doi.org/10.1016/j.gmod.2024.101214","url":null,"abstract":"<div><p>We introduce IGF-Fit, a novel method for estimating surface normals from point clouds with varying noise and density. Unlike previous approaches that rely on point-wise weights and explicit representations, IGF-Fit employs a network that learns an implicit representation and uses derivatives to predict normals. The input patch serves as both a shape latent vector and query points for fitting the implicit representation. To handle noisy input, we introduce a novel noise transformation module with a training strategy for noise classification and latent vector bias prediction. Our experiments on synthetic and real-world scan datasets demonstrate the effectiveness of IGF-Fit, achieving state-of-the-art performance on both noise-free and density-varying data.</p></div>","PeriodicalId":55083,"journal":{"name":"Graphical Models","volume":"133 ","pages":"Article 101214"},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S152407032400002X/pdfft?md5=49f2d24bca30ab2fb9811c74fa197c78&pid=1-s2.0-S152407032400002X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139993418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphical ModelsPub Date : 2024-06-01Epub Date: 2024-05-25DOI: 10.1016/j.gmod.2024.101220
Weiping Pan
{"title":"An exact algorithm for two-dimensional cutting problems based on multi-level pattern","authors":"Weiping Pan","doi":"10.1016/j.gmod.2024.101220","DOIUrl":"https://doi.org/10.1016/j.gmod.2024.101220","url":null,"abstract":"<div><p>A multi-level pattern is proposed for the unconstrained two-dimensional cutting problems of rectangular items, and an exact generation algorithm is constructed. The arrangement of rectangular items with the same type in multiple rows and columns is referred to as a 0-level pattern. An <em>n</em>-level pattern is the horizontal or vertical combination of an <em>n</em>-1 level pattern with a pattern whose level will not exceed <em>n</em>-1. The generation algorithm of multi-level pattern is constructed on the base of dynamic programming, and the multi-level patterns with various sizes are generated with increased level order. The normal size is chosen to reduce unnecessary computation in the algorithm. Three sets of benchmark instances and one set of random production instance from the literatures are used for comparison. Comparing to the exact algorithm in the literature, the results in this paper are equivalent, but the computation time is shorter. Comparing to heuristic algorithms in literatures, the results in this paper are better and the computation time is still good enough for practical applications.</p></div>","PeriodicalId":55083,"journal":{"name":"Graphical Models","volume":"133 ","pages":"Article 101220"},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1524070324000080/pdfft?md5=7ba46c24bfd0defb95fae7879ef5f757&pid=1-s2.0-S1524070324000080-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141095105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphical ModelsPub Date : 2024-06-01Epub Date: 2024-03-13DOI: 10.1016/j.gmod.2024.101215
Xiaokang Liu , Lin Lu , Lingxin Cao , Oliver Deussen , Changhe Tu
{"title":"Auxetic dihedral Escher tessellations","authors":"Xiaokang Liu , Lin Lu , Lingxin Cao , Oliver Deussen , Changhe Tu","doi":"10.1016/j.gmod.2024.101215","DOIUrl":"https://doi.org/10.1016/j.gmod.2024.101215","url":null,"abstract":"<div><p>The auxetic structure demonstrates an unconventional deployable mechanism, expanding in transverse directions while being stretched longitudinally (exhibiting a negative Poisson’s ratio). This characteristic offers advantages in diverse fields such as structural engineering, flexible electronics, and medicine. The rotating (semi-)rigid structure, as a typical auxetic structure, has been introduced into the field of computer-aided design because of its well-defined motion patterns. These structures find application as deployable structures in various endeavors aiming to approximate and rapidly fabricate doubly-curved surfaces, thereby mitigating the challenges associated with their production and transportation. Nevertheless, prior designs relying on basic geometric elements primarily concentrate on exploring the inherent nature of the structure and often lack aesthetic appeal. To address this limitation, we propose a novel design and generation method inspired by dihedral Escher tessellations. By introducing a new metric function, we achieve efficient evaluation of shape deployability as well as filtering of tessellations, followed by a two-step deformation and edge-deployability optimization process to ensure compliance with deployability constraints while preserving semantic meanings. Furthermore, we optimize the shape through physical simulation to guarantee deployability in actual manufacturing and control Poisson’s ratio to a certain extent. Our method yields structures that are both semantically meaningful and aesthetically pleasing, showcasing promising potential for auxetic applications.</p></div>","PeriodicalId":55083,"journal":{"name":"Graphical Models","volume":"133 ","pages":"Article 101215"},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1524070324000031/pdfft?md5=ee39dfa2350ffc88d6645119c393baed&pid=1-s2.0-S1524070324000031-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140122375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphical ModelsPub Date : 2024-04-01Epub Date: 2024-02-02DOI: 10.1016/j.gmod.2024.101213
Flávio Coutinho , Luiz Chaimowicz
{"title":"Pixel art character generation as an image-to-image translation problem using GANs","authors":"Flávio Coutinho , Luiz Chaimowicz","doi":"10.1016/j.gmod.2024.101213","DOIUrl":"10.1016/j.gmod.2024.101213","url":null,"abstract":"<div><p>Asset creation in game development usually requires multiple iterations until a final version is achieved. This iterative process becomes more significant when the content is pixel art, in which the artist carefully places each pixel. We hypothesize that the problem of generating character sprites in a target pose (e.g., facing right) given a source (e.g., facing front) can be framed as an image-to-image translation task. Then, we present an architecture of deep generative models that takes as input an image of a character in one domain (pose) and transfers it to another. We approach the problem using generative adversarial networks (GANs) and build on Pix2Pix’s architecture while leveraging some specific characteristics of the pixel art style. We evaluated the trained models using four small datasets (less than 1k) and a more extensive and diverse one (12k). The models yielded promising results, and their generalization capacity varies according to the dataset size and variability. After training models to generate images among four domains (i.e., front, right, back, left), we present an early version of a mixed-initiative sprite editor that allows users to interact with them and iterate in creating character sprites.</p></div>","PeriodicalId":55083,"journal":{"name":"Graphical Models","volume":"132 ","pages":"Article 101213"},"PeriodicalIF":1.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1524070324000018/pdfft?md5=d7948e383c160b41fc886121e68e438f&pid=1-s2.0-S1524070324000018-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139661295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphical ModelsPub Date : 2024-02-01Epub Date: 2024-01-03DOI: 10.1016/j.gmod.2023.101212
Gabriel Fonseca Silva, Paulo Ricardo Knob, Rubens Halbig Montanha, Soraia Raupp Musse
{"title":"Evaluating and comparing crowd simulations: Perspectives from a crowd authoring tool","authors":"Gabriel Fonseca Silva, Paulo Ricardo Knob, Rubens Halbig Montanha, Soraia Raupp Musse","doi":"10.1016/j.gmod.2023.101212","DOIUrl":"10.1016/j.gmod.2023.101212","url":null,"abstract":"<div><p>Crowd simulation is a research area widely used in diverse fields, including gaming and security, assessing virtual agent movements through metrics like time to reach their goals, speed, trajectories, and densities. This is relevant for security applications, for instance, as different crowd configurations can determine the time people spend in environments trying to evacuate them. In this work, we extend WebCrowds, an authoring tool for crowd simulation, to allow users to build scenarios and evaluate them through a set of metrics. The aim is to provide a quantitative metric that can, based on simulation data, select the best crowd configuration in a certain environment. We conduct experiments to validate our proposed metric in multiple crowd simulation scenarios and perform a comparison with another metric found in the literature. The results show that experts in the domain of crowd scenarios agree with our proposed quantitative metric.</p></div>","PeriodicalId":55083,"journal":{"name":"Graphical Models","volume":"131 ","pages":"Article 101212"},"PeriodicalIF":1.7,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1524070323000425/pdfft?md5=99cc8b127e117c8937d599aa1f5ebafe&pid=1-s2.0-S1524070323000425-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139084586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphical ModelsPub Date : 2023-12-01Epub Date: 2023-11-08DOI: 10.1016/j.gmod.2023.101208
Jan Martens, Jörg Blankenbach
{"title":"A decomposition scheme for continuous Level of Detail, streaming and lossy compression of unordered point clouds","authors":"Jan Martens, Jörg Blankenbach","doi":"10.1016/j.gmod.2023.101208","DOIUrl":"https://doi.org/10.1016/j.gmod.2023.101208","url":null,"abstract":"<div><p>Modern laser scanners, depth sensor devices and Dense Image Matching techniques allow for capturing of extensive point cloud datasets. While capturing has become more user-friendly, the size of registered point clouds results in large datasets which pose challenges for processing, storage and visualization. This paper presents a decomposition scheme using oriented KD trees and the wavelet transform for unordered point clouds. Taking inspiration from image pyramids, the decomposition scheme comes with a Level of Detail representation where higher-levels are progressively reconstructed from lower ones, thus making it suitable for streaming and continuous Level of Detail. Furthermore, the decomposed representation allows common compression techniques to achieve higher compression ratios by modifying the underlying frequency data at the cost of geometric accuracy and therefore allows for flexible lossy compression. After introducing this novel decomposition scheme, results are discussed to show how it deals with data captured from different sources.</p></div>","PeriodicalId":55083,"journal":{"name":"Graphical Models","volume":"130 ","pages":"Article 101208"},"PeriodicalIF":1.7,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1524070323000383/pdfft?md5=acb2ab838184d4b7e97e6052e64a6ea6&pid=1-s2.0-S1524070323000383-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92047097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphical ModelsPub Date : 2023-12-01Epub Date: 2023-10-07DOI: 10.1016/j.gmod.2023.101205
Hao Hua , Benjamin Dillenburger
{"title":"Packing problems on generalised regular grid: Levels of abstraction using integer linear programming","authors":"Hao Hua , Benjamin Dillenburger","doi":"10.1016/j.gmod.2023.101205","DOIUrl":"https://doi.org/10.1016/j.gmod.2023.101205","url":null,"abstract":"<div><p>Packing a designated set of shapes on a regular grid is an important class of operations research problems that has been intensively studied for more than six decades. Representing a <span><math><mi>d</mi></math></span>-dimensional discrete grid as <span><math><msup><mrow><mi>Z</mi></mrow><mrow><mi>d</mi></mrow></msup></math></span>, we formalise the generalised regular grid (GRG) as a surjective function from <span><math><msup><mrow><mi>Z</mi></mrow><mrow><mi>d</mi></mrow></msup></math></span> to a geometric tessellation in a physical space, for example, the cube coordinates of a hexagonal grid or a quasilattice. This study employs 0-1 integer linear programming (ILP) to formulate the polyomino tiling problem with adjacency constraints. Rotation & reflection invariance in adjacency are considered. We separate the formal ILP from the topology & geometry of various grids, such as Ammann-Beenker tiling, Penrose tiling and periodic hypercube. Based on cutting-edge solvers, we reveal an intuitive correspondence between the integer program (a pattern of algebraic rules) and the computer codes. Models of packing problems in the GRG have wide applications in production system, facility layout planning, and architectural design. Two applications in planning high-rise residential apartments are illustrated.</p></div>","PeriodicalId":55083,"journal":{"name":"Graphical Models","volume":"130 ","pages":"Article 101205"},"PeriodicalIF":1.7,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49889742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Editorial special issue on the 9th smart tools and applications in graphics conference (STAG 2022)","authors":"Daniela Cabiddu , Gianmarco Cherchi , Teseo Schneider","doi":"10.1016/j.gmod.2023.101203","DOIUrl":"10.1016/j.gmod.2023.101203","url":null,"abstract":"","PeriodicalId":55083,"journal":{"name":"Graphical Models","volume":"130 ","pages":"Article 101203"},"PeriodicalIF":1.7,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1524070323000334/pdfft?md5=5e8e5ee6713dd442b9a08e76744aae09&pid=1-s2.0-S1524070323000334-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135638180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}