Simple quad domains for field aligned mesh parametrization
Tarini M., Puppo E., Panozzi, D., Pietroni N., Cignoni P.
We present a method for the global parametrization of meshes that
preserves alignment to a cross field in input while obtaining a parametric
domain made of few coarse axis-aligned rectangular patches,
which form an abstract base complex without T-junctions. The
method is based on the topological simplification of the cross field
in input, followed by global smoothing.Source: SIGGRAPH Asia Conference, SA'11, Hog Kong, China, 12-15 December 2011
Archivio istituzionale della ricerca - Università dell'Insubria | ACM Transactions on Graphics | academic.microsoft.com | ACM Transactions on Graphics | air.unimi.it | core.ac.uk | dblp.uni-trier.de | dl.acm.org | ACM Transactions on Graphics | ACM Transactions on Graphics | dl.acm.org | doi.acm.org | doi.org | nyuscholars.nyu.edu | CNR ExploRA | www.scopus.com
Visual computing library
Cignoni P., Ganovelli F., Ponchio F., Pietroni N., Corsini M., Ranzuglia G., Di Benedetto M., Tarini M., Dellepiane M.
The VCG library is a portable C++ templated library for manipulation, processing and displaying with OpenGL polygon meshes. The library, released under the GPL license is the result of the collaborative efforts of the Visual Computing Lab ( VCGLab ) of the ISTI - institute of the Italian National Research Council. The new release includes new data structures to handle half edges and generic polygonal meshes and includes the Eigen2 library for math support.
Global parametrization of range image sets
Pietroni N., Tarini M., Sorkine O., Zorin D.
We present a method to globally parameterize a surface represented by height maps over a set of planes (range images). In contrast to other parametrization techniques, we do not start with a manifold mesh. The parametrization we compute defines a manifold structure, it is seamless and globally smooth, can be aligned to geometric features and shows good quality in terms of angle and area preservation, comparable to current parametrization techniques for meshes. Computing such global seamless parametrization makes it possible to perform quad remeshing, texture mapping and texture synthesis and many other types of geometry processing operations. Our approach is based on a formulation of the Poisson equation on a manifold structure defined for the surface by the range images. Construction of such global parametrization requires only a way to project surface data onto a set of planes, and can be applied directly to implicit surfaces, nonmanifold surfaces, very large meshes, and collections of range scans. We demonstrate application of our technique to all these geometry types.Source: ACM transactions on graphics (Online) 30 (2011). doi:10.1145/2070781.2024183
Project(s): HCC: Medium: Robust and Accurate Modeling with Multifield Geometry , V-MUST.NET
Archivio istituzionale della ricerca - Università dell'Insubria | ACM Transactions on Graphics | academic.microsoft.com | ACM Transactions on Graphics | air.unimi.it | core.ac.uk | dblp.uni-trier.de | ACM Transactions on Graphics | ACM Transactions on Graphics | dl.acm.org | doi.acm.org | nyuscholars.nyu.edu | CNR ExploRA | www.scopus.com
An interactive local flattening operator to support digital investigations on artwork surfaces
Pietroni N., Corsini M., Cignoni P., Scopigno R.
Analyzing either high-frequency shape detail or any other 2D fields (scalar or vector) embedded over a 3D geometry is a complex task, since detaching the detail from the overall shape can be tricky. An alternative approach is to move to the 2D space, resolving shape reasoning to easier image processing techniques. In this paper we propose a novel framework for the analysis of 2D information distributed over 3D geometry, based on a locally smooth parametrization technique that allows us to treat local 3D data in terms of image content. The proposed approach has been implemented as a sketch-based system that allows to design with a few gestures a set of (possibly overlapping) parameterizations of rectangular portions of the surface. We demonstrate that, due to the locality of the parametrization, the distortion is under an acceptable threshold, while discontinuities can be avoided since the parametrized geometry is always homeomorphic to a disk. We show the effectiveness of the proposed technique to solve specific Cultural Heritage (CH) tasks: the analysis of chisel marks over the surface of a unfinished sculpture and the local comparison of multiple photographs mapped over the surface of an artwork. For this very difficult task, we believe that our framework and the corresponding tool are the first steps toward a computer-based shape reasoning system, able to support CH scholars with a medium they are more used to.Source: IEEE transactions on visualization and computer graphics (Online) 17 (2011): 1986–1989. doi:10.1109/TVCG.2011.165
IEEE Transactions on Visualization and Computer Graphics | IEEE Transactions on Visualization and Computer Graphics | IEEE Transactions on Visualization and Computer Graphics | IEEE Transactions on Visualization and Computer Graphics | IEEE Transactions on Visualization and Computer Graphics | IEEE Transactions on Visualization and Computer Graphics | IEEE Transactions on Visualization and Computer Graphics | CNR ExploRA | IEEE Transactions on Visualization and Computer Graphics | IEEE Transactions on Visualization and Computer Graphics | IEEE Transactions on Visualization and Computer Graphics | IEEE Transactions on Visualization and Computer Graphics | IEEE Transactions on Visualization and Computer Graphics
New techniques for computer-based simulation in surgical training
Turini Giuseppe, Pietroni Nico, Megali Giuseppe, Ganovelli Fabio, Pietrabissa Andrea, Mosca Franco
In the recent decades robotics and computer science have been gaining more and more relevance in all aspects of our lives. In surgery, for example, they gave birth to procedures, impossible to perform otherwise, like the tele-surgery or the nano-surgery. On this regard, these applied sciences already play an important role in assisting the surgeon both in the operative room and, as a support, in the education of young surgeons, but much work has still to be done. In fact in these last years we have seen an extreme change in the traditional training in surgery and the computer-based simulation is one of the main reason of this shift. The spread of Minimally Invasive Surgery (MIS) has brought major improvements in the quality of healthcare, but it has also increased the complexity of the surgical procedures requiring advanced and highly specialized training systems. Moreover these training procedures need to be reiterated during the operational life of surgeons. Therefore, considering the limited availability of cadavers and the public concern with the non-ethical treatment of animals, the traditional approaches to surgical training are drastically limited encouraging the use of surgical simulators based on virtual environments. Healthcare industries and the scientific community in medicine agree indicating the disruptive potential of the application of Virtual Reality (VR) to the training in the medical field. Therefore the next step is the development of surgical simulators with an high level of realism in order to practice complex procedures in a safe environment. Moreover it is decisive that this evolution is done integrating advanced medical imaging and processing, allowing surgeons to practice simulated interventions on patient specific dataset. The increasing importance of MIS techniques will cause a drastic change in pre-operation planning and basic surgical training. In fact, the features of this kind of surgical approach (the workspace limitation, the 2D vision through a laparoscopic camera and the indirect physical interaction with the patient body) make it possible to use a surgical simulator to train, plan or simulate an intervention, reproducing the visual and tactile feedback of the real surgical procedure on a real patient. This paper presents some research and applicative results on Computer Assisted Surgery (CAS) achieved in the framework of EndoCAS, a newly founded Center of Excellence in Pisa. The research has involved: the development of segmentation algorithms for volumetric datasets, the simulation of bone drilling procedures, the modeling of deformable object cuts and deformations and the simulation of rope interactions during a suture procedure in MIS. All these projects were been developed using a new open source library to support the implementation of techniques for simulating deformable objects. Our purpose is to enhance the surgical training with new improved techniques applied both to the medical imaging and to the computer-based simulation in order to carry the surgical training to a next level of realism.Source: International journal of biomedical engineering and technology (Print) 5 (2011): 303–316. doi:10.1504/IJBET.2011.039923
International Journal of Biomedical Engineering and Technology | International Journal of Biomedical Engineering and Technology | International Journal of Biomedical Engineering and Technology | CNR ExploRA | International Journal of Biomedical Engineering and Technology | www.inderscience.com | International Journal of Biomedical Engineering and Technology