@article {irs17-07, title = {VVS medical workflows: Definition of a static workflow for part-based annotation of wrist bones and web service oriented architecture for executable workflows}, number = {17-07}, year = {2017}, month = {March}, pages = {41 p.}, publisher = {CNR-IMATI}, type = {Working paper}, address = {Genova}, abstract = {

The report describes the extension of the Digital Shape Workbench version 5 (DSW5) for the inclusion of workflows for the analysis and processing of 3D models obtained from medical imaging data. The VVS Workflow Repository (WR) manages the creation, visualization and execution of shape processing workflows. The considered workflows are of two main categories: static and executable. The first category refers a kind of tutorial workflow/pipeline and is used for sharing expert knowledge e.g. for explaining the steps needed when dealing with a specific process. The second one represents chain of executable web services performing specific pipelines of geometric processing functions. The document describes the adopted architecture and structure for their specification and execution.

}, keywords = {On-line repositories, Semantic web, Shape processing}, url = {http://archives.imati.cnr.it/reports/irs17-07}, author = {F. Giannini and M. Pitikakis} } @article {ipa|Conceptual design of shapes in Virtual Environments through the re-use of heterogeneous data|2016, title = {Conceptual design of shapes in Virtual Environments through the re-use of heterogeneous data}, year = {2016}, month = {November}, pages = {23 p.}, institution = {CNR-IMATI}, address = {Genova}, abstract = {

Today, digital data such as 2D images, 3D meshes and 3D point clouds are widely used to design Virtual Environments (VE). Most of the time, only one type of those multimodal data is used to describe and specify the shapes of the objects. However, a single object can be seen as a combination of components linked with constraints specifying the relationships and the rigid transformations defining their arrangement. Thus, the definition of news methods able to combine any kind of multimodal data in an easy way would allow nonexperts of VE to rapidly mock-up objects and scenes. In this paper, we propose a new shape description model together with its associated constraints toolbox enabling the description of complex shapes from multimodal data. Not only rigid transformations are considered but also scale modifications according to the specified context of the constraint setting. The heterogeneous virtual objects (i.e. composed by scalable multimodal components) then result from the resolution of a constraint satisfaction problem through an optimization approach. The proposed approach is illustrated with examples obtained with our prototype software.

}, keywords = {Virtual Reality}, url = {http://irs.imati.cnr.it/reports/irs16-17}, author = {J-P. Pernot and B. Falcidieno and F. Giannini and Z. Li and P. V{\'e}ron} } @article {ipa|Identification of patterns of repeated parts in solid objects|2016, title = {Identification of patterns of repeated parts in solid objects}, year = {2016}, month = {November}, pages = {128 p.}, institution = {CNR-IMATI}, address = {Genova}, abstract = {

The feature-based modeling approach for designing a mechanical component has been widely adopted by most CAD modelers to maintain the design intent on models. A set of higher level information is requested to enrich the usual geometrical and topological data, in terms of feature information. A well known example of semantically significant data of this type is represented by the knowledge of the existence of symmetrical arrangements of repeated subparts in CAD models. Because of the information transferring, repeated modifications of the models and different tolerances used by the various CAD systems, these specific data can be lost. In this report, after having provided the necessary mathematical background and the state of art of the existing symmetry detection methods, we propose an approach for retrieving symmetries involving a set of user-selected sub-parts in a given BRep part model. The approach is based on a preliminary analysis of the position of points (centroids), each of them representing one repeated feature; a further examination on the faces of the sub-parts is performed to confirm the existence of symmetric arrangements. We have provided the description for the detection of linear translational, reflectional, and circular translational patterns of repeated sub-parts.

}, keywords = {shape analysis}, url = {http://irs.imati.cnr.it/reports/irs16-14}, author = {L. Chiang and F. Giannini and M. Monti} } @article {ipa|Identification of patterns of repeated parts in solid objects - Part II|2016, title = {Identification of patterns of repeated parts in solid objects - Part II}, year = {2016}, month = {November}, pages = {54 p.}, institution = {CNR-IMATI}, type = {Working paper}, address = {Genova}, abstract = {

The work described in this report extends the methods described in the report "Identification of Patterns of Repeated Parts in Solid Objects" ([2]) to deal with CAD assemblies and to the detection of additional types of patterns. Specifically rotational and compound patterns of repeated elements are treated. Therefore, references of all notations, definitions and terms of the objects cited in this report can be found in [2]. The Chapter 1 describes the proposed approach to detect rotational patterns of repeated entities in part model, extending the set of types of patterns considered in [1], [2]. Chapter 2 contains the method proposed for assembly models for the detection of symmetric arrangements on components, considering as repeated elements of the patterns the instances of a part or assembly file. Chapter 3 is dedicated to the introduction of the concept of compound pattern, intended as an improvement of the quality of the symmetry information of a model, obtained by combining the information referred to the patterns of repeated elements. The approach has been described and provided either for part and assembly models.

}, keywords = {shape analysis}, url = {http://irs.imati.cnr.it/reports/irs16-15}, author = {L. Chiang and F. Giannini and M. Monti} } @article {ipa|Mapping aesthetic properties to 3D free form shapes through the use of a machine learning based framework|2016, title = {Mapping aesthetic properties to 3D free form shapes through the use of a machine learning based framework}, year = {2016}, month = {November}, pages = {27 p.}, institution = {CNR-IMATI}, type = {Working paper}, address = {Genova}, abstract = {

Current production is moving from the mass production concept to the product customization and personalization. Customers are not anymore only buyers. Not only they are becoming actors within the Product Development Process (PDP) but, thanks to new production technologies like 3D printers, they can be both designers and producers. In this scenario, the development of user-friendly design tools is crucial. Declarative approaches are suitable and can address such requirements. They exploit generally understood and shared concepts closer to the way people perceive shapes than to the way shapes are modeled with complex geometric models. To this aim, this paper presents a generic framework for understanding the shape characteristics associated to perceptual/aesthetic properties of 3D free form shapes. This framework is used to investigate whether there is a common judgment to characterize the flatness of surfaces and which are the surface shape characteristics affecting the flatness perception? From the experiments, it results that the size and transition of the surrounding influence the perception of the flatness of a given surface strengthening the classification consistency.

}, keywords = {Machine Learning Application}, url = {http://irs.imati.cnr.it/reports/irs16-16}, author = {A. Petrov and J-P. Pernot and F. Giannini and B. Falcidieno} }