2001
Journal article
Restricted
Generating random points in a tetrahedon
Rocchini C, Cignoni P
This paper proposes a simple and efficient technique to generae uniformly random point in a tetrahedron.Source: JOURNAL OF GRAPHICS TOOLS, vol. 5 (issue 4), pp. 9-12
Rocchini C, Cignoni P
This paper proposes a simple and efficient technique to generae uniformly random point in a tetrahedron.Source: JOURNAL OF GRAPHICS TOOLS, vol. 5 (issue 4), pp. 9-12
2008
Conference article
Restricted
3D enhanced model from multiple data sources for the analysis of the Cylinder seal of Ibni-Sharrum
Cignoni P, Pitzalis D, Menu M, Aitken G
In this paper we present the result of the integration of multiple data sources of different 3D acquisition techniques. These acquisitions have been done in order to create a new way to document works of art that have been applied to the "Cylinder seal of Ibni-Sharrum". X-ray tomography has been used to reveal the exact position of inclusions and the presence fissure in the mineral structure; optical micro topography gives the prints of the surface of the seal with a unparallelled precision of up to 0.1?m. Finally a lower resolution 3D model obtained via photogrammetry has been used as a starting point where the tomographic and micro topographic data sets have been superimposed and integrated without precision loss. Furthermore, the textures obtained from HDR photographs has been registered and merged onto the high resolution mesh. These methods have pros and cons that will be discussed and the final obtained model will be the sum of all the complementary cons. The final result of this interdisciplinary investigation will help the curator to better describe the fabrication tech- niques used in order to achieve the final object and a contemporary artist to do a reproduction of the cylinder at a scale of 1000:1.
Cignoni P, Pitzalis D, Menu M, Aitken G
In this paper we present the result of the integration of multiple data sources of different 3D acquisition techniques. These acquisitions have been done in order to create a new way to document works of art that have been applied to the "Cylinder seal of Ibni-Sharrum". X-ray tomography has been used to reveal the exact position of inclusions and the presence fissure in the mineral structure; optical micro topography gives the prints of the surface of the seal with a unparallelled precision of up to 0.1?m. Finally a lower resolution 3D model obtained via photogrammetry has been used as a starting point where the tomographic and micro topographic data sets have been superimposed and integrated without precision loss. Furthermore, the textures obtained from HDR photographs has been registered and merged onto the high resolution mesh. These methods have pros and cons that will be discussed and the final obtained model will be the sum of all the complementary cons. The final result of this interdisciplinary investigation will help the curator to better describe the fabrication tech- niques used in order to achieve the final object and a contemporary artist to do a reproduction of the cylinder at a scale of 1000:1.
See at:
diglib.eg.org 
| CNR IRIS | CNR IRIS
2005
Other
Open Access
A comparison of systems and tools for 3D scanning
Ter Haar F, Cignoni P, Min P, Veltkamp R
Many 3D scanning systems and software tools are currently available, but a comparative study of their actual precision and robustness still lacks. To this end, this paper presents a comparison of such systems, taking into consideration three alignment tools and two merging tools for the management of scanned data. The comparison will be based on the scanning and reconstruction of two relatively complex artistic sculptures and a number of 'ground truth' objects. The quality of the reconstructed 3D models is evaluated using both qualitative and quantitative measures. Quantitative evaluation is performed using Metro, a tool for computing differences between 3D meshes.
Ter Haar F, Cignoni P, Min P, Veltkamp R
Many 3D scanning systems and software tools are currently available, but a comparative study of their actual precision and robustness still lacks. To this end, this paper presents a comparison of such systems, taking into consideration three alignment tools and two merging tools for the management of scanned data. The comparison will be based on the scanning and reconstruction of two relatively complex artistic sculptures and a number of 'ground truth' objects. The quality of the reconstructed 3D models is evaluated using both qualitative and quantitative measures. Quantitative evaluation is performed using Metro, a tool for computing differences between 3D meshes.
See at:
CNR IRIS 
| ISTI Repository | CNR IRIS
2005
Contribution to book
Restricted
Generating random points in a tetrahedron
Cignoni P, Rocchini C
This paper proposes a simple and e±cient technique to generate uniformly random points in a tetrahedron. The technique generates random points in a cube, and folds the cube into the barycentric space of the tetrahedron in a way that preserves uniformity.
Cignoni P, Rocchini C
This paper proposes a simple and e±cient technique to generate uniformly random points in a tetrahedron. The technique generates random points in a cube, and folds the cube into the barycentric space of the tetrahedron in a way that preserves uniformity.
2006
Other
Metadata Only Access
See at:
CNR IRIS
2006
Software
Metadata Only Access
QuteMol
Marco Tarini, Paolo Cignoni
QuteMol is an open source (GPL), interactive, high quality molecular visualization system. QuteMol exploits the current GPU capabilites through OpenGL shaders to offers an array of innovative visual effects. QuteMol visualization techniques are aimed at improving clarity and an easier understanding of the 3D shape and structure of large molecules or complex proteins.
Marco Tarini, Paolo Cignoni
QuteMol is an open source (GPL), interactive, high quality molecular visualization system. QuteMol exploits the current GPU capabilites through OpenGL shaders to offers an array of innovative visual effects. QuteMol visualization techniques are aimed at improving clarity and an easier understanding of the 3D shape and structure of large molecules or complex proteins.
See at:
CNR IRIS
2006
Software
Metadata Only Access
OctreeMerge2
Cignoni P, Fiorin V
Il prodotto software permette di estrarre superfici da un modello volumetrico ottenuto da dati grezzi di scansione 3D (range scan 3D).
Cignoni P, Fiorin V
Il prodotto software permette di estrarre superfici da un modello volumetrico ottenuto da dati grezzi di scansione 3D (range scan 3D).
See at:
CNR IRIS
2006
Software
Metadata Only Access
Metro
Cignoni P
Metro: strumento per il confronto geometrico di superfici triangolate basato sulla misura di Hausdorff. Il sistema è diventato lo strumento di riferimento, da quasi dieci anni, nell'ambito della comunità scientifica internazionale. Metro, aggiornato regolarmente, è attualmente utilizzato praticamente da tutti i maggiori centri di ricerca nel mondo per valutare in modo oggettivo la differenza tra due superfici triangolate. Più di 350 articoli scientifici ne citano esplicitamente il suo utilizzo. Sorgente e binari sono distribuiti liberamente sotto licenza GPL.
Cignoni P
Metro: strumento per il confronto geometrico di superfici triangolate basato sulla misura di Hausdorff. Il sistema è diventato lo strumento di riferimento, da quasi dieci anni, nell'ambito della comunità scientifica internazionale. Metro, aggiornato regolarmente, è attualmente utilizzato praticamente da tutti i maggiori centri di ricerca nel mondo per valutare in modo oggettivo la differenza tra due superfici triangolate. Più di 350 articoli scientifici ne citano esplicitamente il suo utilizzo. Sorgente e binari sono distribuiti liberamente sotto licenza GPL.
See at:
CNR IRIS
2016
Conference article
Restricted
Harvesting dynamic 3DWorlds from commodity sensor clouds
Boubekeur T, Cignoni P, Eisemann E
The EU FP7 FET-Open project "Harvest4D: Harvesting Dynamic 3D Worlds from Commodity Sensor Clouds" deals with the acquisition, processing, and display of dynamic 3D data. Technological progress is offering us a wide-spread availability of sensing devices that deliver different data streams, which can be easily deployed in the real world and produce streams of sampled data with increased density and easier iteration of the sampling process. These data need to be processed and displayed in a new way. The Harvest4D project proposes a radical change in acquisition and processing technology: instead of a goaldriven acquisition that determines the devices and sensors, its methods let the sensors and resulting available data determine the acquisition process. A variety of challenging problems need to be solved: huge data amounts, different modalities, varying scales, dynamic, noisy and colorful data. This short contribution presents a selection of the many scientific results produced by Harvest4D. We will focus on those results that could bring a major impact to the Cultural Heritage domain, namely facilitating the acquisition of the sampled data or providing advanced visual analysis capabilities.
Boubekeur T, Cignoni P, Eisemann E
The EU FP7 FET-Open project "Harvest4D: Harvesting Dynamic 3D Worlds from Commodity Sensor Clouds" deals with the acquisition, processing, and display of dynamic 3D data. Technological progress is offering us a wide-spread availability of sensing devices that deliver different data streams, which can be easily deployed in the real world and produce streams of sampled data with increased density and easier iteration of the sampling process. These data need to be processed and displayed in a new way. The Harvest4D project proposes a radical change in acquisition and processing technology: instead of a goaldriven acquisition that determines the devices and sensors, its methods let the sensors and resulting available data determine the acquisition process. A variety of challenging problems need to be solved: huge data amounts, different modalities, varying scales, dynamic, noisy and colorful data. This short contribution presents a selection of the many scientific results produced by Harvest4D. We will focus on those results that could bring a major impact to the Cultural Heritage domain, namely facilitating the acquisition of the sampled data or providing advanced visual analysis capabilities.
See at:
diglib.eg.org | CNR IRIS | CNR IRIS
2017
Conference article
Metadata Only Access
Tecnologie 3D per i beni culturali
Cignoni P
Le tecnologie digitali 3D stanno trasformando il modo in cui ricercatori, restauratori, curatori lavorano quotidianamente, fornendo nuovi modi per collaborare, documentare scavi e ritrovamenti e restaurare artefatti.
Cignoni P
Le tecnologie digitali 3D stanno trasformando il modo in cui ricercatori, restauratori, curatori lavorano quotidianamente, fornendo nuovi modi per collaborare, documentare scavi e ritrovamenti e restaurare artefatti.
See at:
CNR IRIS
2022
Journal article
Open Access
SkinMixer: blending 3D animated models
Nuvoli S., Pietroni N., Cignoni P., Scateni R., Tarini M.
We propose a novel technique to compose new 3D animated models, such as videogame characters, by combining pieces from existing ones. Our method works on production-ready rigged, skinned, and animated 3D models to reassemble new ones. We exploit mix-and-match operations on the skeletons to trigger the automatic creation of a new mesh, linked to the new skeleton by a set of skinning weights and complete with a set of animations. The resulting model preserves the quality of the input meshings (which can be quad-dominant and semi-regular), skinning weights (inducing believable deformation), and animations, featuring coherent movements of the new skeleton. Our method enables content creators to reuse valuable, carefully designed assets by assembling new ready-to-use characters while preserving most of the hand-crafted subtleties of models authored by digital artists. As shown in the accompanying video, it allows for drastically cutting the time needed to obtain the final result.Source: ACM TRANSACTIONS ON GRAPHICS, vol. 41 (issue 6), pp. 1-15
Nuvoli S., Pietroni N., Cignoni P., Scateni R., Tarini M.
We propose a novel technique to compose new 3D animated models, such as videogame characters, by combining pieces from existing ones. Our method works on production-ready rigged, skinned, and animated 3D models to reassemble new ones. We exploit mix-and-match operations on the skeletons to trigger the automatic creation of a new mesh, linked to the new skeleton by a set of skinning weights and complete with a set of animations. The resulting model preserves the quality of the input meshings (which can be quad-dominant and semi-regular), skinning weights (inducing believable deformation), and animations, featuring coherent movements of the new skeleton. Our method enables content creators to reuse valuable, carefully designed assets by assembling new ready-to-use characters while preserving most of the hand-crafted subtleties of models authored by digital artists. As shown in the accompanying video, it allows for drastically cutting the time needed to obtain the final result.Source: ACM TRANSACTIONS ON GRAPHICS, vol. 41 (issue 6), pp. 1-15
See at:
dl.acm.org | CNR IRIS | ISTI Repository | CNR IRIS | CNR IRIS | CNR IRIS
1998
Conference article
Open Access
1998
Other
Open Access
Scientific Visualization based on Simplicial Complexes
Cignoni P
The main objective of the thesis is the development of a complete and efficient set of solutions for the Scientific Visualization (SciViz), the computer science field which deals with the study, design and implementation of algorithms and data structures for the visualization of scientific data. We propose the adoption of the simplicial complexes as the unifying geometric structure and we show how the choice of this structure as kernel geometric primitive is effective both for the theoretical and practical aspects of SciViz. The contents of the thesis can be summarized as follows. We interpret the diversified SciViz process as a two-steps mapping problem: a modeling step, in which data are mapped into geometry with visual attributes, and a rendering step where geometry and visual attributes are transformed into images. As unifying geometric structure for the modeling step we propose the adoption of the simplicial complexes. To validate our approach we define new algorithms and data structures for the SciViz problems, based on the use of the simplicial complex as basic geometric representation scheme. In particular the thesis supplies original solutions and results to the following problems: 1. Visualization of scalar volume datasets: optimizing techniques for the extraction of isosurface and for the direct volume rendering; 2. Depth sorting of simplicial complexes (a fundamental topic for the efficient and correct use of direct volume rendering based on projective techniques); 3. Integration of isosurface extraction techniques and direct volume rendering techniques. Definition of the concept of discontinuous transfer functions; 4. Simplification of the geometric complexity of simplicial complexes (in order to speed up the visualization process) while minimizing the introduced error; 5. Multiresolution representation schemes for simplicial complexes. These schemes permit both the visualization of complexes at different levels of details and the visualization of a single complex in which different parts are at different resolution.
Cignoni P
The main objective of the thesis is the development of a complete and efficient set of solutions for the Scientific Visualization (SciViz), the computer science field which deals with the study, design and implementation of algorithms and data structures for the visualization of scientific data. We propose the adoption of the simplicial complexes as the unifying geometric structure and we show how the choice of this structure as kernel geometric primitive is effective both for the theoretical and practical aspects of SciViz. The contents of the thesis can be summarized as follows. We interpret the diversified SciViz process as a two-steps mapping problem: a modeling step, in which data are mapped into geometry with visual attributes, and a rendering step where geometry and visual attributes are transformed into images. As unifying geometric structure for the modeling step we propose the adoption of the simplicial complexes. To validate our approach we define new algorithms and data structures for the SciViz problems, based on the use of the simplicial complex as basic geometric representation scheme. In particular the thesis supplies original solutions and results to the following problems: 1. Visualization of scalar volume datasets: optimizing techniques for the extraction of isosurface and for the direct volume rendering; 2. Depth sorting of simplicial complexes (a fundamental topic for the efficient and correct use of direct volume rendering based on projective techniques); 3. Integration of isosurface extraction techniques and direct volume rendering techniques. Definition of the concept of discontinuous transfer functions; 4. Simplification of the geometric complexity of simplicial complexes (in order to speed up the visualization process) while minimizing the introduced error; 5. Multiresolution representation schemes for simplicial complexes. These schemes permit both the visualization of complexes at different levels of details and the visualization of a single complex in which different parts are at different resolution.
See at:
CNR IRIS | ISTI Repository | CNR IRIS
2019
Journal article
Open Access
HexaLab.net: an online viewer for hexahedral meshes
Bracci M, Tarini M, Pietroni N, Livesu M, Cignoni P
We introduce HexaLab: a WebGL application for real time visualization, exploration and assessment of hexahedral meshes. HexaLab can be used by simply opening www.hexalab.net. Our visualization tool targets both users and scholars. Practitioners who employ hexmeshes for Finite Element Analysis, can readily check mesh quality and assess its usability for simulation. Researchers involved in mesh generation may use HexaLab to perform a detailed analysis of the mesh structure, isolating weak points and testing new solutions to improve on the state of the art and generate high quality images. To this end, we support a wide variety of visualization and volume inspection tools. Our system offers also immediate access to a repository containing all the publicly available meshes produced with the most recent techniques for hexmesh generation. We believe HexaLab, providing a common tool for visualizing, assessing and distributing results, will push forward the recent strive for replicability in our scientific community.Source: COMPUTER AIDED DESIGN, vol. 110, pp. 24-36
Project(s): CHANGE
Bracci M, Tarini M, Pietroni N, Livesu M, Cignoni P
We introduce HexaLab: a WebGL application for real time visualization, exploration and assessment of hexahedral meshes. HexaLab can be used by simply opening www.hexalab.net. Our visualization tool targets both users and scholars. Practitioners who employ hexmeshes for Finite Element Analysis, can readily check mesh quality and assess its usability for simulation. Researchers involved in mesh generation may use HexaLab to perform a detailed analysis of the mesh structure, isolating weak points and testing new solutions to improve on the state of the art and generate high quality images. To this end, we support a wide variety of visualization and volume inspection tools. Our system offers also immediate access to a repository containing all the publicly available meshes produced with the most recent techniques for hexmesh generation. We believe HexaLab, providing a common tool for visualizing, assessing and distributing results, will push forward the recent strive for replicability in our scientific community.Source: COMPUTER AIDED DESIGN, vol. 110, pp. 24-36
Project(s): CHANGE
See at:
CNR IRIS | ISTI Repository | www.sciencedirect.com | CNR IRIS | CNR IRIS
2020
Journal article
Open Access
LoopyCuts: practical feature-preserving block decomposition for strongly hex-dominant meshing
Livesu M., Pietroni N., Puppo E., Sheffer A., Cignoni P.
We present a new fully automatic block-decomposition algorithm for feature preserving, strongly hex-dominant meshing, that yields results with a drastically larger percentage of hex elements than prior art. Our method is guided by a surface field that conforms to both surface curvature and feature lines, and exploits an ordered set of cutting loops that evenly cover the input surface, defining an arrangement of loops suitable for hex-element generation. We decompose the solid into coarse blocks by iteratively cutting it with surfaces bounded by these loops. The vast majority of the obtainedblocks can be turned into hexahedral cells via simple midpoint subdivision. Our method produces pure hexahedral meshes in approximately 80% of the cases, and hex-dominant meshes with less than 2% non-hexahedral cells in the remaining cases. We demonstrate the robustness of our method on70+ models, including CAD objects with features of various complexity, organic and synthetic shapes, and provide extensive comparisons to prior art, demonstrating its superiority.Source: ACM TRANSACTIONS ON GRAPHICS, vol. 39 (issue 4), pp. 1-17
Livesu M., Pietroni N., Puppo E., Sheffer A., Cignoni P.
We present a new fully automatic block-decomposition algorithm for feature preserving, strongly hex-dominant meshing, that yields results with a drastically larger percentage of hex elements than prior art. Our method is guided by a surface field that conforms to both surface curvature and feature lines, and exploits an ordered set of cutting loops that evenly cover the input surface, defining an arrangement of loops suitable for hex-element generation. We decompose the solid into coarse blocks by iteratively cutting it with surfaces bounded by these loops. The vast majority of the obtainedblocks can be turned into hexahedral cells via simple midpoint subdivision. Our method produces pure hexahedral meshes in approximately 80% of the cases, and hex-dominant meshes with less than 2% non-hexahedral cells in the remaining cases. We demonstrate the robustness of our method on70+ models, including CAD objects with features of various complexity, organic and synthetic shapes, and provide extensive comparisons to prior art, demonstrating its superiority.Source: ACM TRANSACTIONS ON GRAPHICS, vol. 39 (issue 4), pp. 1-17
See at:
dl.acm.org | CNR IRIS | CNR IRIS | CNR IRIS
2020
Journal article
Restricted
DHFSlicer: Double Height-Field Slicing for Milling Fixed-Height Materials
Yang J, Araujo C, Vining N, Ferguson Z, Rosales E, Panozzo D, Lefevbre S, Cignoni P, Sheffer A
3-axis milling enables cheap and precise fabrication of target objects from precut slabs of materials such as wood or stone. However, the space of directly millable shapes is limited since a 3-axis mill can only carve a height-field (HF) surface during each milling and their size is bounded by the slab dimensions, one of which, the height, is typically significantly smaller than the other two for many typical materials. Extending 3-axis milling of precut slabs to general arbitrarily-sized shapes requires decomposing them into bounded-height 3-axis millable parts, or slices, which can be individually milled and then assembled to form the target object. We present DHFSlicer, a novel decomposition method that satisfies the above constraints and significantly reduces both milling time and material waste compared to alternative approaches. We satisfy the fabrication constraints by partitioning target objects into double height-field (DHF) slices, which can be fabricated using two milling passes: the HF surface accessible from one side is milled first, the slice is then flipped using appropriate fixtures, and then the second, remaining, HF surface is milled. DHFSlicer uses an efficient coarse-to-fine decomposition process: It first partitions the inputs into maximally coarse blocks that satisfy a local DHF criterion with respect to per-block milling axes, and then cuts each block into well-sized DHF slices. It minimizes milling time and material waste by keeping the slice count small, and maximizing slice height. We validate our method by embedding it within an end-to-end DHF milling pipeline and fabricating objects from slabs of foam, wood, and MDF; demonstrate that using the obtained slices reduces milling time and material waste by 42% on average compared to existing automatic alternatives; and highlight the benefits of DHFSlicer via extensive ablation studies.Source: ACM TRANSACTIONS ON GRAPHICS, vol. 39 (issue 6)
Yang J, Araujo C, Vining N, Ferguson Z, Rosales E, Panozzo D, Lefevbre S, Cignoni P, Sheffer A
3-axis milling enables cheap and precise fabrication of target objects from precut slabs of materials such as wood or stone. However, the space of directly millable shapes is limited since a 3-axis mill can only carve a height-field (HF) surface during each milling and their size is bounded by the slab dimensions, one of which, the height, is typically significantly smaller than the other two for many typical materials. Extending 3-axis milling of precut slabs to general arbitrarily-sized shapes requires decomposing them into bounded-height 3-axis millable parts, or slices, which can be individually milled and then assembled to form the target object. We present DHFSlicer, a novel decomposition method that satisfies the above constraints and significantly reduces both milling time and material waste compared to alternative approaches. We satisfy the fabrication constraints by partitioning target objects into double height-field (DHF) slices, which can be fabricated using two milling passes: the HF surface accessible from one side is milled first, the slice is then flipped using appropriate fixtures, and then the second, remaining, HF surface is milled. DHFSlicer uses an efficient coarse-to-fine decomposition process: It first partitions the inputs into maximally coarse blocks that satisfy a local DHF criterion with respect to per-block milling axes, and then cuts each block into well-sized DHF slices. It minimizes milling time and material waste by keeping the slice count small, and maximizing slice height. We validate our method by embedding it within an end-to-end DHF milling pipeline and fabricating objects from slabs of foam, wood, and MDF; demonstrate that using the obtained slices reduces milling time and material waste by 42% on average compared to existing automatic alternatives; and highlight the benefits of DHFSlicer via extensive ablation studies.Source: ACM TRANSACTIONS ON GRAPHICS, vol. 39 (issue 6)
See at:
dl.acm.org | CNR IRIS | CNR IRIS
2021
Contribution to book
Open Access
Documentazione digitale avanzata in emergenza
Cignoni P
Il contributo descrive la campagna di acquisizione condotta nel maggio 2020 in seguito al ritrovamento di una serie di sepolture di epoca romana durante alcuni scavi per manutenzione delle condotte idriche.
Cignoni P
Il contributo descrive la campagna di acquisizione condotta nel maggio 2020 in seguito al ritrovamento di una serie di sepolture di epoca romana durante alcuni scavi per manutenzione delle condotte idriche.
See at:
CNR IRIS | ISTI Repository | CNR IRIS | CNR IRIS
2021
Journal article
Open Access
Texture Defragmentation for Photo-Reconstructed 3D Models
Maggiordomo A, Cignoni P, Tarini M
We propose a method to improve an existing parametrization (UV-map layout) of a textured 3D model, targeted explicitly at alleviating typical defects afflicting models generated with automatic photo-reconstruction tools from real-world objects. This class of 3D data is becoming increasingly important thanks to the growing popularity of reliable, ready-to-use photogrammetry software packages. The resulting textured models are richly detailed, but their underlying parametrization typically falls short of many practical requirements, particularly exhibiting excessive fragmentation and consequent problems. Producing a completely new UV-map, with standard parametrization techniques, and then resampling a new texture image, is often neither practical nor desirable for at least two reasons: first, these models have characteristics (such as inconsistencies, high resolution) that make them unfit for automatic or manual parametrization; second, the required resampling leads to unnecessary signal degradation because this process is unaware of the original texel densities. In contrast, our method improves the existing UV-map instead of replacing it, balancing the reduction of the map fragmentation with signal degradation due to resampling, while also avoiding oversampling of the original signal. The proposed approach is fully automatic and extensively tested on a large benchmark of photo-reconstructed models; quantitative evaluation evidences a drastic and consistent improvement of the mappingsSource: COMPUTER GRAPHICS FORUM (ONLINE), vol. 40 (issue 2), pp. 65-78
Project(s): ARIADNEplus
Maggiordomo A, Cignoni P, Tarini M
We propose a method to improve an existing parametrization (UV-map layout) of a textured 3D model, targeted explicitly at alleviating typical defects afflicting models generated with automatic photo-reconstruction tools from real-world objects. This class of 3D data is becoming increasingly important thanks to the growing popularity of reliable, ready-to-use photogrammetry software packages. The resulting textured models are richly detailed, but their underlying parametrization typically falls short of many practical requirements, particularly exhibiting excessive fragmentation and consequent problems. Producing a completely new UV-map, with standard parametrization techniques, and then resampling a new texture image, is often neither practical nor desirable for at least two reasons: first, these models have characteristics (such as inconsistencies, high resolution) that make them unfit for automatic or manual parametrization; second, the required resampling leads to unnecessary signal degradation because this process is unaware of the original texel densities. In contrast, our method improves the existing UV-map instead of replacing it, balancing the reduction of the map fragmentation with signal degradation due to resampling, while also avoiding oversampling of the original signal. The proposed approach is fully automatic and extensively tested on a large benchmark of photo-reconstructed models; quantitative evaluation evidences a drastic and consistent improvement of the mappingsSource: COMPUTER GRAPHICS FORUM (ONLINE), vol. 40 (issue 2), pp. 65-78
Project(s): ARIADNEplus
See at:
diglib.eg.org | CNR IRIS | ISTI Repository | CNR IRIS
2023
Journal article
Open Access
Texture inpainting for photogrammetric models
Maggiordomo A, Cignoni P, Tarini M
We devise a technique designed to remove the texturing artefacts that are typical of 3D models representing real-world objects, acquired by photogrammetric techniques. Our technique leverages the recent advancements in inpainting of natural colour images, adapting them to the specific context. A neural network, modified and trained for our purposes, replaces the texture areas containing the defects, substituting them with new plausible patches of texels, reconstructed from the surrounding surface texture. We train and apply the network model on locally reparametrized texture patches, so to provide an input that simplifies the learning process, because it avoids any texture seams, unused texture areas, background, depth jumps and so on. We automatically extract appropriate training data from real-world datasets. We show two applications of the resulting method: one, as a fully automatic tool, addressing all problems that can be detected by analysing the UV-map of the input model; and another, as an interactive semi-automatic tool, presented to the user as a 3D 'fixing' brush that has the effect of removing artefacts from any zone the users paints on. We demonstrate our method on a variety of real-world inputs and provide a reference usable implementation.Source: COMPUTER GRAPHICS FORUM (PRINT)
Maggiordomo A, Cignoni P, Tarini M
We devise a technique designed to remove the texturing artefacts that are typical of 3D models representing real-world objects, acquired by photogrammetric techniques. Our technique leverages the recent advancements in inpainting of natural colour images, adapting them to the specific context. A neural network, modified and trained for our purposes, replaces the texture areas containing the defects, substituting them with new plausible patches of texels, reconstructed from the surrounding surface texture. We train and apply the network model on locally reparametrized texture patches, so to provide an input that simplifies the learning process, because it avoids any texture seams, unused texture areas, background, depth jumps and so on. We automatically extract appropriate training data from real-world datasets. We show two applications of the resulting method: one, as a fully automatic tool, addressing all problems that can be detected by analysing the UV-map of the input model; and another, as an interactive semi-automatic tool, presented to the user as a 3D 'fixing' brush that has the effect of removing artefacts from any zone the users paints on. We demonstrate our method on a variety of real-world inputs and provide a reference usable implementation.Source: COMPUTER GRAPHICS FORUM (PRINT)
See at:
CNR IRIS | onlinelibrary.wiley.com | ISTI Repository | CNR IRIS