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Now showing 1 - 6 of 6
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    Alain Fournier, 1943-2000 An Appreciation
    (Blackwell Publishers Ltd and the Eurographics Association., 2001) Fiume, E.
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    An Efficient Search Algorithm for Motion Data Using Weighted PCA
    (The Eurographics Association, 2005) Forbes, K.; Fiume, E.; D. Terzopoulos and V. Zordan and K. Anjyo and P. Faloutsos
    Good motion data is costly to create. Such an expense often makes the reuse of motion data through transformation and retargetting a more attractive option than creating new motion from scratch. Reuse requires the ability to search automatically and efficiently a growing corpus of motion data, which remains a difficult open problem. We present a method for quickly searching long, unsegmented motion clips for subregions that most closely match a short query clip. Our search algorithm is based on a weighted PCA-based pose representation that allows for flexible and efficient pose-to-pose distance calculations. We present our pose representation and the details of the search algorithm. We evaluate the performance of a prototype search application using both synthetic and captured motion data. Using these results, we propose ways to improve the application s performance. The results inform a discussion of the algorithm s good scalability characteristics.
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    A Temporal Scripting Language for Object-Oriented Animation
    (Eurographics Association, 1987) Fiume, E.; Tsichritzis, D.; Dami, L.
    Object orientation and concurrency are inherent to computer animation. Since the pieces of an animation can come from various media such as computer-generated imagery, video, and sound, the case for object orientation is all the stronger. However, languages for expressing the temporal co-ordination of animated objects have been slow in coming. We present such a language in this paper. Since the movements that an animated object can perform are also encapsulated as objects in our system, the scripting language can also be used to specify motion co-ordination. Such \u2018 motion objects\u201d can be applied to any animated object. The syntax, semantics, and implementation of this language will be described, and we shall show how to specify device-independent computer animation.
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    Sketch-Based Design for Bargello Quilts
    (The Eurographics Association, 2005) Coahran, M.; Fiume, E.; Joaquim Armando Pires Jorge and Takeo Igarashi
    Quilting is an art form in which amateur craftspeople explore geometry and color to create stunning designs. Bargello is a specific quilt style defined by a clever construction method that imposes constraints on the designs and gives them a characteristic appearance. Currently, Bargello patterns are typically designed manually, in a process that is laborious and time-consuming. We have developed a prototype system in which users can design Bargello quilts quickly and easily by sketching curves with a mouse. As a curve is drawn, the system transforms it into a graceful Bargello curve, composed of corner-connected axis-aligned rectangles, that respects both physical constraints and design constraints intrinsic to the Bargello style. We also provide a design setting that supports design variations typical of Bargello quilts and a set of tools to extend simple designs into complex ones. We conducted an informal evaluation of the system in a series of focus group sessions with potential users from the quilting community. Quilters were enthusiastic about the system and also provided suggestions for improvement.
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    Shadow Computation: A Unified Perspective
    (Eurographics Association, 2000) Ghali, S.; Fiume, E.; Seidel, H.-P.
    Methods for solving shadow problems by solving instances of visibility problems have long been known and exploited. There are, however, other potent uses of such a reduction of shadow problems, several of which we explore in this paper. Specifically, we describe algorithms that use a resolution–independent, or object–space, visibility structure for the computation of object–space shadows under point, linear, and area light sources. The connection between object–space visibility and shadow computation is well–known in computer graphics. We show how that fundamental observation can be recast and generalized within an object–space visibility structure. The edges in such a structure contain exactly the information needed to determine shadow edges under a point light source. Also, the locations along a linear or an area light source at which visibility changes (termed critical points and critical lines) provide the necessary information for computing shadow edges resulting from linear and area light sources. Not only are instances of all shadow problems thus reduced to visibility problems, but instances of shadow problems under linear and area light sources are also reduced to instances of shadow generation under point and linear light sources, respectively.
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    Conformal Texture Mapping
    (Eurographics Association, 1987) Fiume, E.; Fournier, A.; Canale, V.
    A new class of geometric mappings is introduced to computer graphics, and the utility of this class is illustrated by applying it to texture mapping. When mapping a texture onto a surface such as a polygon, the entire texture can rarely be mapped without some clipping or non-linear transformation. Is it possible to map a texture bijectively to an arbitrary polygon such that the entire texture is mapped? This paper presents a solution to this problem. A new class of mapping techniques based on conformal mapping is proposed. The technique allows one to construct a continuous, bijective map from a polygonal texture space (e.g., a square) to an arbitrary convex polygon. The resulting map is texture-independent. The theory and .an implementation of conformal texture mapping is discussed, and several simple filtering techniques to support it are outlined. Conformal mapping extends the range of geometric mapping techniques, and is pertinent to many areas of computer graphics. Other examples of the potential utility of conformal mappings are also discussed.