Hi ! Marco Attene
Istituto di Matematica Applicata e Tecnologie Informatiche
Consiglio Nazionale delle Ricerche
Via De Marini, 6 (Torre di Francia)
16149 Genoa - ITALY
Phone: +39-010-6475675
Fax: +39-010-6475660
E-mail: mymail

Biography
Recent_Work
Publications
Software
Activity
Biography

Marco Attene is a researcher at IMATI-GE / CNR, where he investigates new directions, paradigms and algorithms for 3D geometric modelling, processing and analysis. Marco has been the principal investigator at CNR for regional, national and international projects. He is evaluator for the Italian Ministry of Education and Research, and has been the promoter of key collaborations and joint research programs between IMATI and universities in Europe, USA, Asia and New Zaeland. Marco manages seven sourceforge software projects involving experts from the University of Genova and from IMATI. He published high-impact articles (> 1200 citations) on the most prestigious journals in the area (ACM TOG, TVCG, CGF, ...). He gave tutorials, plenary lectures and seminars at national and international schools, and presented his work at all the major computer graphics events including, among the others, ACM Siggraph and Eurographics. Marco contributed to the organization of several international conferences as program committee member, program chair, and organizing committee member. He is an associate editor of international journals in the area, and is the main editor of NoSMoG, the Newsletter of the Shape Modeling Group at IMATI-CNR.

Download a short CV here (last update Jan, 2014).
Recent Work
Polygon Mesh Repairing: an application perspective
Marco Attene, Marcel Campen and Leif Kobbelt
ACM Computing Surveys, Vol. 45, No. 2, Article 15 (33 pages), Feb 2013.

Abstract
Mesh defects Nowadays, digital 3D models are in widespread and ubiquitous use, and each specific application dealing with 3D geometry has its own quality requirements that restrict the class of acceptable and supported models. This article analyzes typical defects that make a 3D model unsuitable for key application contexts, and surveys existing algorithms that process, repair, and improve its structure, geometry, and topology to make it appropriate to case-by-case requirements. The analysis is focused on polygon meshes, which constitute by far the most common 3D object representation. In particular, this article provides a structured overview of mesh repairing techniques from the point of view of the application context. Different types of mesh defects are classified according to the upstream application that produced the mesh, whereas mesh quality requirements are grouped by representative sets of downstream applications where the mesh is to be used. The numerous mesh repair methods that have been proposed during the last two decades are analyzed and classified in terms of their capabilities, properties, and guarantees. Based on these classifications, guidelines can be derived to support the identification of repairing algorithms best-suited to bridge the compatibility gap between the quality provided by the upstream process and the quality required by the downstream applications in a given geometry processing scenario.

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(c) ACM 2013.
>>> Accompanying website
Geometric Models with Weighted Topology
Marco Attene and Silvia Biasotti
Computers and Graphics, Vol. 35, No. 3, June 2011, Pages 542-548. Online version

Blurred solid
Abstract
This paper introduces the concept of weighted topology to model a 3D object whose connectivity and metric depend on a novel notion of weighted arc-length. The weighted arc-length between any two points of the shape takes into account the fact that a part of the object may be either weakly or strongly connected to another part. The new model is useful to treat problems which are intrinsically not robust to small topological changes. We describe an example implementation of the model and show how it can be exploited to (1) extend the applicability domain of existing segmentation algorithms and (2) improve the performances of a shape descriptor in a 3D object retrieval scenario.

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(c)Elsevier 2011.

A lightweight approach to repairing digitized polygon meshes
Marco Attene
The Visual Computer, Vol. 26, N. 11, 1393-1406, 2010. Online version

Abstract
Fixed chair When designing novel algorithms for geometric processing and analysis, researchers often assume that the input conforms to several requirements. On the other hand, polygon meshes obtained from acquisition of real-world objects typically exhibit several defects, and thus are not appropriate for a widespread exploitation. In this paper, an algorithm is presented that strives to convert a low-quality digitized polygon mesh to a single manifold and watertight triangle mesh without degenerate or intersecting elements. Differently from most existing approaches that globally re-sample the model to produce a fixed version, the algorithm presented here attempts to modify the input mesh only locally within the neighborhood of undesired configurations. After having converted the input to a single combinatorial manifold, the algorithm proceeds iteratively by removing growing neighborhoods of undesired elements and by patching the resulting surface gaps until all the "defects" are removed. Though this heuristic approach is not guaranteed to converge, it was tested on more than 400 low-quality models and always succeeded. Furthermore, with respect to similar existing algorithms, it proved to be computationally efficient and to produce more accurate results while using fewer triangles.

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(c) Springer 2010.

>>> Download Software
Characterization of 3D shape parts for semantic annotation
Marco Attene, Francesco Robbiano, Michela Spagnuolo and Bianca Falcidieno
Computer-Aided Design, Vol. 41, No. 10, pp. 756-763, 2009. Online version.

Abstract
ShapeAnnotator 3D content stored in big databases or shared on the Internet is a precious resource for several applications, but unfortunately it risks being underexploited due to the difficulty of retrieving it efficiently. In this paper we describe a system called the ShapeAnnotator through which it is possible to perform non-trivial segmentations of 3D surface meshes and annotate the detected parts through concepts expressed by an ontology. Each part is connected to an instance that can be stored in a knowledge base to ease the retrieval process based on semantics. Through an intuitive interface, users create such instances by simply selecting proper classes in the ontology; attributes and relations with other instances can be computed automatically based on a customizable analysis of the underlying topology and geometry of the parts. We show how our part-based annotation framework can be used in two scenarios, namely for the creation of avatars in emerging Internet-based virtual worlds, and for product design in e-manufacturing.

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(c) Elsevier 2009.

>>> ShapeAnnotator Web Page
Hierarchical Convex Approximation of 3D Shapes for Fast Region Selection
Marco Attene, Michela Mortara, Michela Spagnuolo and Bianca Falcidieno
Computer Graphics Forum, Vol. 27, No. 5, pp. 1323-1333, 2008.

Abstract
HCA Given a 3D solid model S represented by a tetrahedral mesh, we describe a novel algorithm to compute a hierarchy of convex polyhedra that tightly enclose S. The hierarchy can be browsed at interactive speed on a modern PC and it is useful for implementing an intuitive feature selection paradigm for 3D editing environments.
Convex parts often coincide with perceptually relevant shape components and, for their identification, existing methods rely on the boundary surface only. In contrast, we show that the notion of part concavity can be expressed and implemented more intuitively and efficiently by exploiting a tetrahedrization of the shape volume.
The method proposed is completely automatic, and generates a tree of convex polyhedra in which the root is the convex hull of the whole shape, and the leaves are the tetrahedra of the input mesh. The algorithm proceeds bottomup by hierarchically clustering tetrahedra into nearly convex aggregations, and the whole process is significantly fast. We prove that, in the average case, for a mesh of n tetrahedra O(n log^2 n) operations are sufficient to compute the whole tree.

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(c) EUROGRAPHCS / Blackwell Publishing.
Hierarchical Mesh Segmentation based on Fitting Primitives
Marco Attene, Bianca Falcidieno and Michela Spagnuolo
The Visual Computer 22(3): 181-193, 2006.

Abstract
HFP In this paper we describe a hierarchical face clustering algorithm for triangle meshes based on fitting primitives belonging to an arbitrary set. The method proposed is completely automatic, and generates a binary tree of clusters, each of which fitted by one of the primitives employed. Initially, each triangle represents a single cluster; at every iteration, all the pairs of adjacent clusters are considered, and the one that can be better approximated by one of the primitives forms a new single cluster. The approximation error is evaluated using the same metric for all the primitives, so that it makes sense to choose which is the most suitable primitive to approximate the set of triangles in a cluster. Based on this approach, we implemented a prototype which uses planes, spheres and cylinders, and have experimented that for meshes made of 100k faces, the whole binary tree of clusters can be built in about 8 seconds on a standard PC. The framework here described has natural application in reverse engineering processes, but it has been also tested for surface de-nosing, feature recovery and character skinning.

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(c) Springer 2006.

>>> Download Software
Sharpen&Bend:
Recovering curved sharp edges in triangle meshes produced by feature-insensitive sampling
Marco Attene, Bianca Falcidieno, Jarek Rossignac and Michela Spagnuolo
IEEE Transactions on Visualization and Computer Graphics, 11(2): pp. 181-192, 2005.

Abstract
S&B Various acquisition, analysis, visualization and compression approaches sample surfaces of 3D shapes in a uniform fashion, without any attempt to align the samples with sharp edges or to adapt the sampling density to the surface curvature. Consequently, triangle meshes that interpolate these samples usually chamfer sharp features and exhibit a relatively large error in their vicinity. We present two new filters that improve the quality of these re-sampled models. EdgeSharpener restores the sharp edges by splitting the chamfer edges and forcing the new vertices to lie on intersections of planes extending the smooth surfaces incident upon these chamfers. Bender refines the resulting triangle mesh using an interpolating subdivision scheme that preserves the sharpness of the recovered sharp edges while bending their polyline approximations into smooth curves. A combined Sharpen&Bend post-processing significantly reduces the error produced by feature-insensitive sampling processes. For example, we have observed that the mean-squared distortion introduced by the SwingWrapper remeshing-based compressor can often be reduced by 80% executing EdgeSharpener alone after decompression. For models with curved regions, this error may be further reduced by an additional 60% if we follow the EdgeSharpening phase by Bender.

PDF Download PDF (2.38 Mb)  (c) IEEE 2005.
SwingWrapper:
Retiling Triangle Meshes for Better EdgeBreaker Compression
Marco Attene, Bianca Falcidieno, Michela Spagnuolo and Jarek Rossignac
ACM Transactions on Graphics, 22(4): pp. 982-996, 2003.

Abstract
SwingWrapper We focus on the lossy compression of manifold triangle meshes. Our SwingWrapper approach partitions the surface of an original mesh M into simply connected regions, called triangloids. From these, we generate a new mesh M'. Each triangle of M' is an approximation of a triangloid of M. By construction, the connectivity of M' is fairly regular and can be compressed to less than a bit per triangle using EdgeBreaker or one of the other recently developed schemes. The locations of the vertices of M' are compactly encoded with our new prediction technique, which uses a single correction parameter per vertex. SwingWrapper strives to reach a user-defined output file size rather than to guarantee a given error bound. For a variety of popular models, a rate of 0.4 bits/triangle yields an L2 distortion of about 0.01% of the bounding box diagonal. The proposed solution may also be used to encode crude meshes for adaptive transmission or for controlling subdivision surfaces.

PDF Download PDF (777 Kb)  (c) ACM 2003.

Publications (selected)
Complete list in the CV.

ISI Journals
Other International Journals & Book Chapters
Refereed Conference Proceedings
Software
ReMesh is an editor for manifold triangle meshes. Most operations can be performed interactively through mouse-clicks on the mesh. Both low-level (edge-flip, vertex-insert, ...) and high-level (simplification, subdivision, ...) operations are supported.
Go to the official sourceforge project page for further details and download.

MeshFix takes as input a raw digitized polygon mesh and produces a copy of the input where all the occurrences of a specific set of "defects" are corrected. Algorithm based on ideas of "A lightweight approach to repairing digitized polygon meshes" (The Visual Computer, 2010).
Download at sourceforge.net.

ShapeAnnotator is an open source software project based on the paper "Semantic Annotation of 3D Surface Meshes based on Feature Characterization" (LNCS, SAMT 2007 Procs).
Go to the official sourceforge project page for further details and download.

JMeshLib is a C++ API to manage manifold triangle meshes.
Download JMeshLib here.

EfPiSoft is an implementation of the hierarchical segmentation algorithm.
Download EfPiSoft here.

TriMesh2MT is a software tool that converts a surface mesh to a multitriangulation.
Download TriMesh2MT here.

Simplicial is a C++ framework to manage simplicial meshes in arbitrary dimensions.
Download Simplicial here.

Scientific Activity

For boards, committees, editorships, etc. please look at the complete CV.