CRS4 Libro, Contributo in un libro

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https://hdl.handle.net/11050/56

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Mostra il contenuto di CRS4 Libro, Contributo in un libro per Subject "3D animation"

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    An Integrated Environment to Visually Construct 3D Animations
    (ACM, 1995) Gobbetti, Enrico; Balaguer, Jean-Francis
    In this paper, we present an expressive 3D animation environment that enables users to rapidly and visually prototype animated worlds with a fully 3D user-interface. A 3D device allows the specification of complex 3D motion, while virtual tools are visible mediators that live in the same 3D space as application objects and supply the interaction metaphors to control them. In our environment, there is no intrinsic difference between user-interface and application objects. Multi-way constraints provide the necessary tight-coupling among components that makes it possible to seamlessly compose interactive and animated behaviors. By recording the effects of manipulations, all the expressive power of the 3D user-interface is exploited to define animations. Effective editing of recorded manipulations is made possible by compacting all continuous parameter evolutions with an incremental data-reduction algorithm, designed to preserve both geometry and timing. The automatic generation of editable representations of interactive performances overcomes one of the major limitations of current performance animation systems. Novel interactive solutions to animation problems are made possible by the tight integration of all system components. In particular, animations can be synchronized by using constrained manipulation during playback. The accompanying video tape illustrates our approach with interactive sequences showing the visual construction of 3D animated worlds. All the demonstrations were recorded live and were not edited.
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    Improving the digitization of shape and color of 3D artworks in a cluttered environment
    (IEEE, 2013-10) Bettio, Fabio; Gobbetti, Enrico; Merella, Emilio; Pintus, Ruggero
    We propose an approach for improving the digitization of shape and color of 3D artworks in a cluttered environment using 3D laser scanning and flash photography. In order to separate clutter from acquired material, semi-automated methods are employed to generate masks for segment the 2D range maps and the color photographs, removing unwanted 3D and color data prior to 3D integration. Sharp shadows generated by flash acquisition are trivially handled by this masking process, and color deviations introduced by the flash light are corrected at color blending time by taking into account the object geometry. The approach has been applied to, and evaluated on, a large scale acquisition campaign of the Mont'e Prama complex, an extraordinary collection of stone fragments from the Nuragic era, depicting larger-than-life archers, warriors, boxers, as well as small models of prehistoric nuraghe (cone-shaped stone towers). The acquisition campaign has covered 36 statues mounted on metallic supports, acquired at 0.25mm resolution, resulting in over 6200 range scans (over 1.3G valid samples) and 3426 10Mpixel photographs.
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    Supporting interactive animation using multi-way constraints
    (Springer, 1995) Balaguer, Jean-Francis; Gobbetti, Enrico
    This paper presents how the animation subsystem of an interactive environment for the visual construction of 3D animations has been modeled on top of an object-oriented constraint imperative architecture. In our architecture, there is no intrinsic difference between user-interface and application objects. Multi-way dataflow constraints provide the necessary tight coupling among components that makes it possible to seamlessly compose animated and interactive behaviors. Indirect paths allow an effective use of the constraint model in the context of dynamic applications. The ability of the underlying constraint solver to deal with hierarchies of multi-way, multi-output dataflow constraints, together with the ability of the central state manager to handle indirect constraints are exploited to define most of the behaviors of the modeling and animation components in a declarative way. The ease of integration between all system's components opens the door to novel interactive solution to modeling and animation problems. By recording the effects of the user's manipulations on the models, all the expressive power of the 3D user interface is exploited when defining animations. This performance-based approach complements standard key-framing systems by providing the ability to create animations with straight-ahead actions. At the end of the recording session, animation tracks are automatically updated to integrate the new piece of animation. Animation components can be easily synchronized using constrained manipulation during playback. The system demonstrates that, although they are limited to expressing acyclic conflict-free graphs, multi-way dataflow constraint are general enough to model a large variety of behaviors while remaining efficient enough to ensure the responsiveness of large interactive 3D graphics applications.
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    Virtual sardinia: a hypermedia fly-through with real data
    (1995) Gobbetti, Enrico; Leone, Andrea O.; Marini, Alberto
    The Virtual Sardinia project aims at collecting a large amount of heterogeneous data concerning the island of Sardinia and representing them in such a way that a casual user can easily navigate through them in a virtual trip. All these data are interconnected in an hypermedia way, browsable in the World-wide Web, ranging from geographic to archaeological data, from historical to touristical info, both in 2D and 3D. The central component of Virtual Sardinia is i3D, a high-speed 3D scene viewer for the World-wide Web. Using a Spaceball, the user can intuitively navigate with continuous viewpoint control inside three-dimensional data, while selecting 3D objects with the mouse triggers requests for access to remote media documents that can be distributed over the Internet. For the Virtual Sardinia project, the main 3D model that is explored by the users is a three-dimensional reconstruction of the island of Sardinia built from a digital terrain model texture-mapped with satellite images.