2001
Conference article
Restricted
Animating cuts with on-the-fly re-meshing
Ganovelli F, Òsullivan C
The problem of defining a model for deformable objects which allows the user to perform cuts is still open. Generally speaking, the reason is that such a task affects the connectivity and the topology of the mesh, while the assumption that they never change is the basis of most algorithms for both computation of deformation and collision detection. The drawback of approaching this problem as one of cutting based on re-meshing, is that the mesh exhibits a higher density where it has been cut than elsewhere. This paper proposes an on-the-fly tetrahedral simplification scheme to cope with such a fragmentation problem.
Ganovelli F, Òsullivan C
The problem of defining a model for deformable objects which allows the user to perform cuts is still open. Generally speaking, the reason is that such a task affects the connectivity and the topology of the mesh, while the assumption that they never change is the basis of most algorithms for both computation of deformation and collision detection. The drawback of approaching this problem as one of cutting based on re-meshing, is that the mesh exhibits a higher density where it has been cut than elsewhere. This paper proposes an on-the-fly tetrahedral simplification scheme to cope with such a fragmentation problem.
2006
Software
Metadata Only Access
ArchiMesh
Ganovelli F, Spinelli A
Il pacchetto software permette di estrarre da un modello digitale 3D ottenuto con tecnologia 3D scanning informazioni sulle features presenti (spigoli, primitive, etc.).
Ganovelli F, Spinelli A
Il pacchetto software permette di estrarre da un modello digitale 3D ottenuto con tecnologia 3D scanning informazioni sulle features presenti (spigoli, primitive, etc.).
See at:
CNR IRIS 
2001
Conference article
Metadata Only Access
Collision handling for virtual environments
Dingliana J, Ganovelli F, Bradshaw G, Òsullivan Ca
An abstract is not available.
Dingliana J, Ganovelli F, Bradshaw G, Òsullivan Ca
An abstract is not available.
See at:
CNR IRIS
2000
Conference article
Open Access
Buckettree: improving collision detection between deformable objects
Ganovelli F, Dingliana J, Òsullivan C
In recent years, thanks to the increasing computational power available, real time computer animation has naturally evolved to model more complex and computationally expensive scenes. Consequently, all the problems concerning physical modelling need further research to tackle these new requirements, especially the problem of collision detection for deformable objects. Most existing solutions cannot not be trivially extended, because they are strongly based on the assumption that the shape of the object is fixed. In this paper we propose a general approach to reduce the cost of collision detection between deformable objects explicitly represented, regardless of the specific geometrical and physical manner in which they are modelled.
Ganovelli F, Dingliana J, Òsullivan C
In recent years, thanks to the increasing computational power available, real time computer animation has naturally evolved to model more complex and computationally expensive scenes. Consequently, all the problems concerning physical modelling need further research to tackle these new requirements, especially the problem of collision detection for deformable objects. Most existing solutions cannot not be trivially extended, because they are strongly based on the assumption that the shape of the object is fixed. In this paper we propose a general approach to reduce the cost of collision detection between deformable objects explicitly represented, regardless of the specific geometrical and physical manner in which they are modelled.
2014
Conference article
Restricted
Building an IT platform for strategic crisis management preparation
Boin A, Bynander F, Pintore G, Ganovelli F, Leventakis G, Ahmad A, Balet O
This paper presents the result of the work achieved in the frame of three successive European Projects, which aimed to build an innovative system to assist security managers in the crisis preparation, training and management phases. The iterative approach of the consortium is presented, as well as the results. A novel interactive and shared Common Operational Picture is proposed which has been validated by three large scale demonstrations. On-going and future work focusing on the security concepts and measures of building interiors is moreover presented.DOI: 10.1109/wimob.2014.6962144
Project(s): VASCO
Metrics:
Boin A, Bynander F, Pintore G, Ganovelli F, Leventakis G, Ahmad A, Balet O
This paper presents the result of the work achieved in the frame of three successive European Projects, which aimed to build an innovative system to assist security managers in the crisis preparation, training and management phases. The iterative approach of the consortium is presented, as well as the results. A novel interactive and shared Common Operational Picture is proposed which has been validated by three large scale demonstrations. On-going and future work focusing on the security concepts and measures of building interiors is moreover presented.DOI: 10.1109/wimob.2014.6962144
Project(s): VASCO
Metrics:
See at:
doi.org | CNR IRIS | CNR IRIS | CNR IRIS | www.scopus.com
2016
Conference article
Open Access
Assessing the security of buildings: a virtual studio solution
Ahmad A, Balet O, Boin A, Castet J, Donnelley M, Ganovelli F, Kokkinis G, Pintore G
This paper presents an innovative IT solution, a virtual studio, enabling security professionals to formulate, test and adjust security measures to enhance the security of critical buildings. The concept is to virtualize the environment, enabling experts to examine and assess and improve on a buildingâEUR(TM)s security in a cost-effective and risk-free way. Our virtual studio solution makes use of the latest advances in computer graphics to reconstruct accurate blueprints as well as 3D representations of entire buildings in a very short timeframe. In addition, our solution enables the creation and simulation of multiple threat situations, allowing users to assess security procedures and various responses. Furthermore, we present a novel device, tailored to support collaborative security planning needs. Security experts from various disciplines evaluated our virtual studio solution, and their analysis is presented in this paper.Project(s): VASCO
Ahmad A, Balet O, Boin A, Castet J, Donnelley M, Ganovelli F, Kokkinis G, Pintore G
This paper presents an innovative IT solution, a virtual studio, enabling security professionals to formulate, test and adjust security measures to enhance the security of critical buildings. The concept is to virtualize the environment, enabling experts to examine and assess and improve on a buildingâEUR(TM)s security in a cost-effective and risk-free way. Our virtual studio solution makes use of the latest advances in computer graphics to reconstruct accurate blueprints as well as 3D representations of entire buildings in a very short timeframe. In addition, our solution enables the creation and simulation of multiple threat situations, allowing users to assess security procedures and various responses. Furthermore, we present a novel device, tailored to support collaborative security planning needs. Security experts from various disciplines evaluated our virtual studio solution, and their analysis is presented in this paper.Project(s): VASCO
2016
Conference article
Restricted
Omnidirectional image capture on mobile devices for fast automatic generation of 2.5D indoor maps
Pintore G, Garro V, Ganovelli F, Gobbetti E, Agus M
We introduce a light-weight automatic method to quickly capture and recover 2.5D multi-room indoor environments scaled to real-world metric dimensions. To minimize the user effort required, we capture and analyze a single omni-directional image per room using widely available mobile devices. Through a simple tracking of the user movements between rooms, we iterate the process to map and reconstruct entire floor plans. In order to infer 3D clues with a minimal processing and without relying on the presence of texture or detail, we define a specialized spatial transform based on catadioptric theory to highlight the room's structure in a virtual projection. From this information, we define a parametric model of each room to formalize our problem as a global optimization solved by Levenberg-Marquardt iterations. The effectiveness of the method is demonstrated on several challenging real-world multi-room indoor scenes.DOI: 10.1109/wacv.2016.7477631
Project(s): VASCO
Metrics:
Pintore G, Garro V, Ganovelli F, Gobbetti E, Agus M
We introduce a light-weight automatic method to quickly capture and recover 2.5D multi-room indoor environments scaled to real-world metric dimensions. To minimize the user effort required, we capture and analyze a single omni-directional image per room using widely available mobile devices. Through a simple tracking of the user movements between rooms, we iterate the process to map and reconstruct entire floor plans. In order to infer 3D clues with a minimal processing and without relying on the presence of texture or detail, we define a specialized spatial transform based on catadioptric theory to highlight the room's structure in a virtual projection. From this information, we define a parametric model of each room to formalize our problem as a global optimization solved by Levenberg-Marquardt iterations. The effectiveness of the method is demonstrated on several challenging real-world multi-room indoor scenes.DOI: 10.1109/wacv.2016.7477631
Project(s): VASCO
Metrics:
See at:
doi.org | CNR IRIS | ieeexplore.ieee.org | CNR IRIS
1999
Other
Open Access
Models for deformable objects modeling thesis proposal
Ganovelli F
The evolution of Computer Graphics methodologies in the last two decades has been impressive, opening many opportunities to work on new problems and applications. Sophisticated techniques are available for visualizing complex scenes and to support user interaction and immersion with virtual worlds. An active research domain ls nowadays how to extend graphics technology to include in interactive and immersive graphic contexts those objects whose shape could be deformed depending on the forces that act on them. The problem becomes more difficult if we require that these deformations have to be physically based, i.e. coherent with some properties which the objects are supposed to have. The field of Soft Object Modeling or, more generally, Soft Object Animation has been investigated for the last ten years and a wide range of very different approaches has been proposed, with a main orientation to animation and offline simulation. Following this trend, we intend to introduce concepts and techniques strictly related to interactive graphics modeling and visualization in order to develop methods and data representations for Soft Object Modeling that could be used for immersive and interactive applications. In this field, the classical compromise is between real-time performance and accuracy. Our aim is not to search methodology that could improve simulation accuracy (in the sense of more sophisticated descriptions of deformation), but to search for feasible techniques that should produce realistic simulations with a much cheaper processing cost, to fulfill the constraint of interactive/real time feedback. The application domain where the methodologies proposed will be evaluated is the virtual simulation of soft tissue for medical applications. This choice will introduce a number of application-oriented constraints, but we plan to design highly general representation techniques and methodologies that should not be restricted to the test application domain.
Ganovelli F
The evolution of Computer Graphics methodologies in the last two decades has been impressive, opening many opportunities to work on new problems and applications. Sophisticated techniques are available for visualizing complex scenes and to support user interaction and immersion with virtual worlds. An active research domain ls nowadays how to extend graphics technology to include in interactive and immersive graphic contexts those objects whose shape could be deformed depending on the forces that act on them. The problem becomes more difficult if we require that these deformations have to be physically based, i.e. coherent with some properties which the objects are supposed to have. The field of Soft Object Modeling or, more generally, Soft Object Animation has been investigated for the last ten years and a wide range of very different approaches has been proposed, with a main orientation to animation and offline simulation. Following this trend, we intend to introduce concepts and techniques strictly related to interactive graphics modeling and visualization in order to develop methods and data representations for Soft Object Modeling that could be used for immersive and interactive applications. In this field, the classical compromise is between real-time performance and accuracy. Our aim is not to search methodology that could improve simulation accuracy (in the sense of more sophisticated descriptions of deformation), but to search for feasible techniques that should produce realistic simulations with a much cheaper processing cost, to fulfill the constraint of interactive/real time feedback. The application domain where the methodologies proposed will be evaluated is the virtual simulation of soft tissue for medical applications. This choice will introduce a number of application-oriented constraints, but we plan to design highly general representation techniques and methodologies that should not be restricted to the test application domain.
2019
Journal article
Open Access
Automatic modeling of cluttered multi-room floor plans from panoramic images
Pintore G, Ganovelli F, Villanueva Aj, Gobbetti E
We present a novel and light-weight approach to capture and reconstruct structured 3D models of multi-room floor plans. Starting from a small set of registered panoramic images, we automatically generate a 3D layout of the rooms and of all the main objects inside. Such a 3D layout is directly suitable for use in a number of real-world applications, such as guidance, location, routing, or content creation for security and energy management. Our novel pipeline introduces several contributions to indoor reconstruction from purely visual data. In particular, we automatically partition panoramic images in a connectivity graph, according to the visual layout of the rooms, and exploit this graph to support object recovery and rooms boundaries extraction. Moreover, we introduce a plane-sweeping approach to jointly reason about the content of multiple images and solve the problem of object inference in a top-down 2D domain. Finally, we combine these methods in a fully automated pipeline for creating a structured 3D model of a multi-room floor plan and of the location and extent of clutter objects. These contribution make our pipeline able to handle cluttered scenes with complex geometry that are challenging to existing techniques. The effectiveness and performance of our approach is evaluated on both real-world and synthetic models.Source: COMPUTER GRAPHICS FORUM (PRINT), vol. 38 (issue 7), pp. 347-358
DOI: 10.1111/cgf.13842
Metrics:
Pintore G, Ganovelli F, Villanueva Aj, Gobbetti E
We present a novel and light-weight approach to capture and reconstruct structured 3D models of multi-room floor plans. Starting from a small set of registered panoramic images, we automatically generate a 3D layout of the rooms and of all the main objects inside. Such a 3D layout is directly suitable for use in a number of real-world applications, such as guidance, location, routing, or content creation for security and energy management. Our novel pipeline introduces several contributions to indoor reconstruction from purely visual data. In particular, we automatically partition panoramic images in a connectivity graph, according to the visual layout of the rooms, and exploit this graph to support object recovery and rooms boundaries extraction. Moreover, we introduce a plane-sweeping approach to jointly reason about the content of multiple images and solve the problem of object inference in a top-down 2D domain. Finally, we combine these methods in a fully automated pipeline for creating a structured 3D model of a multi-room floor plan and of the location and extent of clutter objects. These contribution make our pipeline able to handle cluttered scenes with complex geometry that are challenging to existing techniques. The effectiveness and performance of our approach is evaluated on both real-world and synthetic models.Source: COMPUTER GRAPHICS FORUM (PRINT), vol. 38 (issue 7), pp. 347-358
DOI: 10.1111/cgf.13842
Metrics:
See at:
CNR IRIS 
| onlinelibrary.wiley.com | ISTI Repository | Computer Graphics Forum | CNR IRIS | CNR IRIS
2020
Other
Open Access
Automatic 3D Reconstruction of Structured Indoor Environments
Pintore G, Mura C, Ganovelli F, Fuentesperez L, Pajarola R, Gobbetti E
Creating high-level structured 3D models of real-world indoor scenes from captured data is a fundamental task which has important applications in many fields. Given the complexity and variability of interior environments and the need to cope with noisy and partial captured data, many open research problems remain, despite the substantial progress made in the past decade. In this tutorial, we provide an up-to-date integrative view of the field, bridging complementary views coming from computer graphics and computer vision. After providing a characterization of input sources, we define the structure of output models and the priors exploited to bridge the gap between imperfect sources and desired output. We then identify and discuss the main components of a structured reconstruction pipeline, and review how they are combined in scalable solutions working at the building level. We finally point out relevant research issues and analyze research trends.DOI: 10.1145/3388769.3407469
DOI: 10.5167/uzh-190473
Project(s): EVOCATION, ENCORE
Metrics:
Pintore G, Mura C, Ganovelli F, Fuentesperez L, Pajarola R, Gobbetti E
Creating high-level structured 3D models of real-world indoor scenes from captured data is a fundamental task which has important applications in many fields. Given the complexity and variability of interior environments and the need to cope with noisy and partial captured data, many open research problems remain, despite the substantial progress made in the past decade. In this tutorial, we provide an up-to-date integrative view of the field, bridging complementary views coming from computer graphics and computer vision. After providing a characterization of input sources, we define the structure of output models and the priors exploited to bridge the gap between imperfect sources and desired output. We then identify and discuss the main components of a structured reconstruction pipeline, and review how they are combined in scalable solutions working at the building level. We finally point out relevant research issues and analyze research trends.DOI: 10.1145/3388769.3407469
DOI: 10.5167/uzh-190473
Project(s): EVOCATION
, ENCORE Metrics:
See at:
CRS4 Open Archive | Zurich Open Repository and Archive | www.zora.uzh.ch | dl.acm.org | doi.org | doi.org | CNR IRIS | CNR IRIS
2020
Journal article
Open Access
State-of-the-art in Automatic 3D Reconstruction of Structured Indoor Environments
Pintore G, Mura C, Ganovelli F, Fuentesperez L, Pajarola R, Gobbetti E
Creating high-level structured 3D models of real-world indoor scenes from captured data is a fundamental task which has important applications in many fields. Given the complexity and variability of interior environments and the need to cope with noisy and partial captured data, many open research problems remain, despite the substantial progress made in the past decade. In this survey, we provide an up-to-date integrative view of the field, bridging complementary views coming from computer graphics and computer vision. After providing a characterization of input sources, we define the structure of output models and the priors exploited to bridge the gap between imperfect sources and desired output. We then identify and discuss the main components of a structured reconstruction pipeline, and review how they are combined in scalable solutions working at the building level. We finally point out relevant research issues and analyze research trends.Source: COMPUTER GRAPHICS FORUM (PRINT), vol. 39 (issue 2), pp. 667-699
DOI: 10.1111/cgf.14021
DOI: 10.5167/uzh-190475
Project(s): EVOCATION, ENCORE
Metrics:
Pintore G, Mura C, Ganovelli F, Fuentesperez L, Pajarola R, Gobbetti E
Creating high-level structured 3D models of real-world indoor scenes from captured data is a fundamental task which has important applications in many fields. Given the complexity and variability of interior environments and the need to cope with noisy and partial captured data, many open research problems remain, despite the substantial progress made in the past decade. In this survey, we provide an up-to-date integrative view of the field, bridging complementary views coming from computer graphics and computer vision. After providing a characterization of input sources, we define the structure of output models and the priors exploited to bridge the gap between imperfect sources and desired output. We then identify and discuss the main components of a structured reconstruction pipeline, and review how they are combined in scalable solutions working at the building level. We finally point out relevant research issues and analyze research trends.Source: COMPUTER GRAPHICS FORUM (PRINT), vol. 39 (issue 2), pp. 667-699
DOI: 10.1111/cgf.14021
DOI: 10.5167/uzh-190475
Project(s): EVOCATION
, ENCORE Metrics:
See at:
CRS4 Open Archive | CNR IRIS | onlinelibrary.wiley.com | Computer Graphics Forum | Zurich Open Repository and Archive | CNR IRIS
2007
Journal article
Restricted
Texturing internal surfaces from a few cross sections
Pietroni N, Otaduy M, Bickel B, Ganovelli F, Gross M
We introduce a new appearance-modeling paradigm for synthesizing the internal structure of a 3D model from photographs of a few cross-sections of a real object. When the internal surfaces of the 3D model are revealed as it is cut, carved, or simply clipped, we synthesize their texture from the input photographs. Our texture synthesis algorithm is best classified as a morphing technique, which efficiently outputs the texture attributes of each surface point on demand. For determining source points and their weights in the morphing algorithm, we propose an interpolation domain based on BSP trees that naturally resembles planar splitting of real objects. In the context of the interpolation domain, we define efficient warping and morphing operations that allow for real-time synthesis of textures. Overall, our modeling paradigm, together with its realization through our texture synthesis algorithm, allow users to author 3D models that reveal highly realistic internal surfaces in a variety of artistic flavors.Source: COMPUTER GRAPHICS FORUM (PRINT), vol. 26 (issue 3), pp. 637-644
DOI: 10.1111/j.1467-8659.2007.01087.x
Metrics:
Pietroni N, Otaduy M, Bickel B, Ganovelli F, Gross M
We introduce a new appearance-modeling paradigm for synthesizing the internal structure of a 3D model from photographs of a few cross-sections of a real object. When the internal surfaces of the 3D model are revealed as it is cut, carved, or simply clipped, we synthesize their texture from the input photographs. Our texture synthesis algorithm is best classified as a morphing technique, which efficiently outputs the texture attributes of each surface point on demand. For determining source points and their weights in the morphing algorithm, we propose an interpolation domain based on BSP trees that naturally resembles planar splitting of real objects. In the context of the interpolation domain, we define efficient warping and morphing operations that allow for real-time synthesis of textures. Overall, our modeling paradigm, together with its realization through our texture synthesis algorithm, allow users to author 3D models that reveal highly realistic internal surfaces in a variety of artistic flavors.Source: COMPUTER GRAPHICS FORUM (PRINT), vol. 26 (issue 3), pp. 637-644
DOI: 10.1111/j.1467-8659.2007.01087.x
Metrics:
See at:
diglib.eg.org | Computer Graphics Forum | CNR IRIS | CNR IRIS
2009
Journal article
Restricted
eNVyMyCar: a multiplayer car racing game for teaching computer graphics
Ganovelli F, Corsini M
The development of a computer game is widely used as a way of conveying concepts regarding Computer Science. There are several reasons for this: it stimulates creativity, it provides an immediate sense of achievement (when the code works), it typically covers all the aspects of an introductory course, and it is easy to find ideas just by looking around and finding stimulation from one's environment and from fellow students. In this paper we present eNVyMyCar, a framework for the collaborative/competitive development of a computer game, and report the experience of its use in two Computer Graphics courses held in 2007. We developed a multiplayer car racing game where the student's task is just to implement the rendering of the scene, while all the other aspects, communication and synchronization are implemented in the framework and are transparent to the developer. The innovative feature of our framework is that all on-line users can see the views produced by their fellow students. This motivates students to improve their work by comparing it with other students and picking up ideas from them. It also gives students an opportunity to show off to their classmates.Source: COMPUTER GRAPHICS FORUM (PRINT), vol. 28 (issue 8), pp. 2025-2032
DOI: 10.1111/j.1467-8659.2009.01425.x
Metrics:
Ganovelli F, Corsini M
The development of a computer game is widely used as a way of conveying concepts regarding Computer Science. There are several reasons for this: it stimulates creativity, it provides an immediate sense of achievement (when the code works), it typically covers all the aspects of an introductory course, and it is easy to find ideas just by looking around and finding stimulation from one's environment and from fellow students. In this paper we present eNVyMyCar, a framework for the collaborative/competitive development of a computer game, and report the experience of its use in two Computer Graphics courses held in 2007. We developed a multiplayer car racing game where the student's task is just to implement the rendering of the scene, while all the other aspects, communication and synchronization are implemented in the framework and are transparent to the developer. The innovative feature of our framework is that all on-line users can see the views produced by their fellow students. This motivates students to improve their work by comparing it with other students and picking up ideas from them. It also gives students an opportunity to show off to their classmates.Source: COMPUTER GRAPHICS FORUM (PRINT), vol. 28 (issue 8), pp. 2025-2032
DOI: 10.1111/j.1467-8659.2009.01425.x
Metrics:
See at:
Computer Graphics Forum | CNR IRIS | CNR IRIS | onlinelibrary.wiley.com
2003
Journal article
Restricted
Fast tetrahedron-tetrahedron overlap algorithm
Ganovelli F, Ponchio F, Rocchini C
We present an algorithm to test two tetrahedra for overlap. The algorithm is based on a dimension reduction technique that allows to apply the Separating Axis Theorem avoiding part of the computation needed to perform the Separating Axis Test. Source code is available online.Source: ACM TRANSACTIONS ON INTELLIGENT SYSTEMS AND TECHNOLOGY (PRINT), vol. 7, pp. 17-26
Ganovelli F, Ponchio F, Rocchini C
We present an algorithm to test two tetrahedra for overlap. The algorithm is based on a dimension reduction technique that allows to apply the Separating Axis Theorem avoiding part of the computation needed to perform the Separating Axis Test. Source code is available online.Source: ACM TRANSACTIONS ON INTELLIGENT SYSTEMS AND TECHNOLOGY (PRINT), vol. 7, pp. 17-26
2005
Conference article
Restricted
Robust segmentation of anatomical structures with deformable surfaces and marching cubes
Pietroni N, Giachetti A, Ganovelli F
Computer assisted medical applications require often the reconstruction of anatomical structures to compute parameters useful for diagnosis or interventional planning. From CT and MRI datasets it is possible to obtain surface models of the organs of interest with a variety of algorithms, like Marching Cubes, level sets or deformable parametric surfaces. Each technique has advantages but also drawbacks like noise sensitivity (isosurface extraction), risk of leakages (level sets), oversmoothing and impossible handling of topological changes (Deformable models). To obtain a good trade-off between robustness, shape constraints and topological control, we propose a 3D balloon/isosurface method joining the advantages in curvature control, leakage penalization and efficiency of parametric surfaces with a fast re-parametrization handling topological changes. It is based on the control of surface self-intersections, freezing of the intersected nodes and replacement of the final mesh with an isosurface computed on a field representing the signed distance from the true surface.
Pietroni N, Giachetti A, Ganovelli F
Computer assisted medical applications require often the reconstruction of anatomical structures to compute parameters useful for diagnosis or interventional planning. From CT and MRI datasets it is possible to obtain surface models of the organs of interest with a variety of algorithms, like Marching Cubes, level sets or deformable parametric surfaces. Each technique has advantages but also drawbacks like noise sensitivity (isosurface extraction), risk of leakages (level sets), oversmoothing and impossible handling of topological changes (Deformable models). To obtain a good trade-off between robustness, shape constraints and topological control, we propose a 3D balloon/isosurface method joining the advantages in curvature control, leakage penalization and efficiency of parametric surfaces with a fast re-parametrization handling topological changes. It is based on the control of surface self-intersections, freezing of the intersected nodes and replacement of the final mesh with an isosurface computed on a field representing the signed distance from the true surface.
2006
Conference article
Restricted
Simulating drilling on tetrahedral meshes
Turini G, Ganovelli F, Montani C
Bone drilling is a fundamental task in several surgical procedures, including mastoidectomy, cochlear implantation, orbital surgery. It consists in eroding the part of the bone in contact with the tip of the surgical tool when a sufficient pressure is exerted. Since the bone is an almost rigid material, the bone drilling simulations usually employ voxel-based representations of the bone, so that it is easy to show material removal by playing with material density in the voxels. Unfortunately, there are cases in which drilling is only a part of the task, and parts of the same object are also cut away or, worse, the bone is slightly deformable and therefore voxel-based representations do not work well. We propose a novel method to simulate drilling on objects represented explicitly by means of a tetrahedral mesh. The key idea of our method is to create an alternative representation of the tetrahedron when it is partially eroded. Such representation consists of a set of smaller tetrahedra obtained by a hierarchical decomposition of the original one, and combined to represent the current status of the erosion.
Turini G, Ganovelli F, Montani C
Bone drilling is a fundamental task in several surgical procedures, including mastoidectomy, cochlear implantation, orbital surgery. It consists in eroding the part of the bone in contact with the tip of the surgical tool when a sufficient pressure is exerted. Since the bone is an almost rigid material, the bone drilling simulations usually employ voxel-based representations of the bone, so that it is easy to show material removal by playing with material density in the voxels. Unfortunately, there are cases in which drilling is only a part of the task, and parts of the same object are also cut away or, worse, the bone is slightly deformable and therefore voxel-based representations do not work well. We propose a novel method to simulate drilling on objects represented explicitly by means of a tetrahedral mesh. The key idea of our method is to create an alternative representation of the tetrahedron when it is partially eroded. Such representation consists of a set of smaller tetrahedra obtained by a hierarchical decomposition of the original one, and combined to represent the current status of the erosion.
2007
Conference article
Open Access
Techniques for Computer Assisted Surgery
Turini G, Pietroni N, Ganovelli F, Scopigno R
In the recent decades robotic 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 that would be impossible to perform otherwise (e.g. tele-surgery, 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. This paper presents some research and applicative results on Computer Assisted Surgery achieved in the framework of Endocas, a newly founded Center of Excellence in Pisa: A method for segmentation of anatomic parts from 3D dataset able to recover shapes from noisy 3D dataset; A technique for simulating bone drilling using a adaptive decomposition of tetrahedral meshes; A new open source library to support the implementation of techniques for simulating deformable objects
Turini G, Pietroni N, Ganovelli F, Scopigno R
In the recent decades robotic 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 that would be impossible to perform otherwise (e.g. tele-surgery, 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. This paper presents some research and applicative results on Computer Assisted Surgery achieved in the framework of Endocas, a newly founded Center of Excellence in Pisa: A method for segmentation of anatomic parts from 3D dataset able to recover shapes from noisy 3D dataset; A technique for simulating bone drilling using a adaptive decomposition of tetrahedral meshes; A new open source library to support the implementation of techniques for simulating deformable objects
2007
Conference article
Restricted
A robust method for real-time thread simulation
Kubiak B, Pietroni N, Ganovelli F, Fratarcangeli M
We present a physically based model for real-time simulation of thread dynamics. Our model captures all the relevant aspects of the physics of the thread, including quasi-zero elasticit, bending, torsion and self-collision, and it provides output forces for the haptic feedback. The physical properties are modeled in terms of constraints that are iteratively satisfied while the numerical integration is carried out through a Verlet scheme. This approach leads to an unconditionally stable, controllable and computationally light simulation. Our results demonstrate the effectiveness of our model, showing the interaction of the thread with other objects in real time and the creation of complex knots.
Kubiak B, Pietroni N, Ganovelli F, Fratarcangeli M
We present a physically based model for real-time simulation of thread dynamics. Our model captures all the relevant aspects of the physics of the thread, including quasi-zero elasticit, bending, torsion and self-collision, and it provides output forces for the haptic feedback. The physical properties are modeled in terms of constraints that are iteratively satisfied while the numerical integration is carried out through a Verlet scheme. This approach leads to an unconditionally stable, controllable and computationally light simulation. Our results demonstrate the effectiveness of our model, showing the interaction of the thread with other objects in real time and the creation of complex knots.
See at:
dl.acm.org | CNR IRIS | CNR IRIS
2008
Conference article
Restricted
EnVyMyCar: a multi-player car racing game for teaching computer graphics
Ganovelli F, Corsini M
The development of a computer game is widely used as a means to convey Computer Sciences concepts. There are several reasons for that: it is stimulates creativity, it provides an immediate sense of achievement when the code works, it typically covers all the aspects of an introductory course, it is easy to find ideas just looking around. In this paper we present NVMC (EnVy My Car), a framework for collaborative/competitive development of a computer game and report the experience in using it in two computer graphics courses held in the year 2007 by the authors. We developed a multiplayer car racing game where the student is only asked to implement the rendering of the scene, while all the other aspects, communication and synchronization are implemented in the framework and transparent to the developer. The novelty of our framework is that all the clients on-line are able to see the views provided by the other clients, which serves to motivate the students to improve their work by comparing it with the other clients, as a means to pick up ideas from the others and finally to show off with their classmates.DOI: 10.2312/eged.20081000
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Ganovelli F, Corsini M
The development of a computer game is widely used as a means to convey Computer Sciences concepts. There are several reasons for that: it is stimulates creativity, it provides an immediate sense of achievement when the code works, it typically covers all the aspects of an introductory course, it is easy to find ideas just looking around. In this paper we present NVMC (EnVy My Car), a framework for collaborative/competitive development of a computer game and report the experience in using it in two computer graphics courses held in the year 2007 by the authors. We developed a multiplayer car racing game where the student is only asked to implement the rendering of the scene, while all the other aspects, communication and synchronization are implemented in the framework and transparent to the developer. The novelty of our framework is that all the clients on-line are able to see the views provided by the other clients, which serves to motivate the students to improve their work by comparing it with the other clients, as a means to pick up ideas from the others and finally to show off with their classmates.DOI: 10.2312/eged.20081000
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2005
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Robust segmentation of anatomical structures with deformable surfaces and marching cubes
Pietroni N, Ganovelli F, Giachetti A
Computer assisted medical applications require often the reconstruction of anatomical structures to compute parameters useful for diagnosis or interventional planning. From CT and MRI datasets it is possible to obtain surface models of the organs of interest with a variety of algorithms, like Marching Cubes, level sets or deformable parametric surfaces. Each technique has advantages but also drawbacks like noise sensitivity (isosurface extraction), risk of leakages (level sets), oversmoothing and impossible handling of topological changes (Deformable models). To obtain a good trade-off between robustness, shape constraints and topological control, we propose a 3D balloon/isosurface method joining the advantages in curvature control, leakage penalization and efficiency of parametric surfaces with a fast re-parametrization handling topological changes. It is based on the control of surface self-intersections, freezing of the intersected nodes and replacement of the final mesh with an isosurface computed on a field representing the signed distance from the true surface.
Pietroni N, Ganovelli F, Giachetti A
Computer assisted medical applications require often the reconstruction of anatomical structures to compute parameters useful for diagnosis or interventional planning. From CT and MRI datasets it is possible to obtain surface models of the organs of interest with a variety of algorithms, like Marching Cubes, level sets or deformable parametric surfaces. Each technique has advantages but also drawbacks like noise sensitivity (isosurface extraction), risk of leakages (level sets), oversmoothing and impossible handling of topological changes (Deformable models). To obtain a good trade-off between robustness, shape constraints and topological control, we propose a 3D balloon/isosurface method joining the advantages in curvature control, leakage penalization and efficiency of parametric surfaces with a fast re-parametrization handling topological changes. It is based on the control of surface self-intersections, freezing of the intersected nodes and replacement of the final mesh with an isosurface computed on a field representing the signed distance from the true surface.