4,909 research outputs found

    Interactive Sketching of Mannequin Poses

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    It can be easy and even fun to sketch humans in different poses. In contrast, creating those same poses on a 3D graphics 'mannequin' is comparatively tedious. Yet 3D body poses are necessary for various downstream applications. We seek to preserve the convenience of 2D sketching while giving users of different skill levels the flexibility to accurately and more quickly pose/refine a 3D mannequin. At the core of the interactive system, we propose a machine-learning model for inferring the 3D pose of a CG mannequin from sketches of humans drawn in a cylinder-person style. Training such a model is challenging because of artist variability, a lack of sketch training data with corresponding ground truth 3D poses, and the high dimensionality of human pose-space. Our unique approach to synthesizing vector graphics training data underpins our integrated ML-and-kinematics system. We validate the system by tightly coupling it with a user interface, and by performing a user study, in addition to quantitative comparisons

    LiveCap: Real-time Human Performance Capture from Monocular Video

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    We present the first real-time human performance capture approach that reconstructs dense, space-time coherent deforming geometry of entire humans in general everyday clothing from just a single RGB video. We propose a novel two-stage analysis-by-synthesis optimization whose formulation and implementation are designed for high performance. In the first stage, a skinned template model is jointly fitted to background subtracted input video, 2D and 3D skeleton joint positions found using a deep neural network, and a set of sparse facial landmark detections. In the second stage, dense non-rigid 3D deformations of skin and even loose apparel are captured based on a novel real-time capable algorithm for non-rigid tracking using dense photometric and silhouette constraints. Our novel energy formulation leverages automatically identified material regions on the template to model the differing non-rigid deformation behavior of skin and apparel. The two resulting non-linear optimization problems per-frame are solved with specially-tailored data-parallel Gauss-Newton solvers. In order to achieve real-time performance of over 25Hz, we design a pipelined parallel architecture using the CPU and two commodity GPUs. Our method is the first real-time monocular approach for full-body performance capture. Our method yields comparable accuracy with off-line performance capture techniques, while being orders of magnitude faster

    Embodied Interactions for Spatial Design Ideation: Symbolic, Geometric, and Tangible Approaches

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    Computer interfaces are evolving from mere aids for number crunching into active partners in creative processes such as art and design. This is, to a great extent, the result of mass availability of new interaction technology such as depth sensing, sensor integration in mobile devices, and increasing computational power. We are now witnessing the emergence of maker culture that can elevate art and design beyond the purview of enterprises and professionals such as trained engineers and artists. Materializing this transformation is not trivial; everyone has ideas but only a select few can bring them to reality. The challenge is the recognition and the subsequent interpretation of human actions into design intent

    Sketch-based skeleton-driven 2D animation and motion capture.

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    This research is concerned with the development of a set of novel sketch-based skeleton-driven 2D animation techniques, which allow the user to produce realistic 2D character animation efficiently. The technique consists of three parts: sketch-based skeleton-driven 2D animation production, 2D motion capture and a cartoon animation filter. For 2D animation production, the traditional way is drawing the key-frames by experienced animators manually. It is a laborious and time-consuming process. With the proposed techniques, the user only inputs one image ofa character and sketches a skeleton for each subsequent key-frame. The system then deforms the character according to the sketches and produces animation automatically. To perform 2D shape deformation, a variable-length needle model is developed, which divides the deformation into two stages: skeleton driven deformation and nonlinear deformation in joint areas. This approach preserves the local geometric features and global area during animation. Compared with existing 2D shape deformation algorithms, it reduces the computation complexity while still yielding plausible deformation results. To capture the motion of a character from exiting 2D image sequences, a 2D motion capture technique is presented. Since this technique is skeleton-driven, the motion of a 2D character is captured by tracking the joint positions. Using both geometric and visual features, this problem can be solved by ptimization, which prevents self-occlusion and feature disappearance. After tracking, the motion data are retargeted to a new character using the deformation algorithm proposed in the first part. This facilitates the reuse of the characteristics of motion contained in existing moving images, making the process of cartoon generation easy for artists and novices alike. Subsequent to the 2D animation production and motion capture,"Cartoon Animation Filter" is implemented and applied. Following the animation principles, this filter processes two types of cartoon input: a single frame of a cartoon character and motion capture data from an image sequence. It adds anticipation and follow-through to the motion with related squash and stretch effect

    Robust Temporally Coherent Laplacian Protrusion Segmentation of 3D Articulated Bodies

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    In motion analysis and understanding it is important to be able to fit a suitable model or structure to the temporal series of observed data, in order to describe motion patterns in a compact way, and to discriminate between them. In an unsupervised context, i.e., no prior model of the moving object(s) is available, such a structure has to be learned from the data in a bottom-up fashion. In recent times, volumetric approaches in which the motion is captured from a number of cameras and a voxel-set representation of the body is built from the camera views, have gained ground due to attractive features such as inherent view-invariance and robustness to occlusions. Automatic, unsupervised segmentation of moving bodies along entire sequences, in a temporally-coherent and robust way, has the potential to provide a means of constructing a bottom-up model of the moving body, and track motion cues that may be later exploited for motion classification. Spectral methods such as locally linear embedding (LLE) can be useful in this context, as they preserve "protrusions", i.e., high-curvature regions of the 3D volume, of articulated shapes, while improving their separation in a lower dimensional space, making them in this way easier to cluster. In this paper we therefore propose a spectral approach to unsupervised and temporally-coherent body-protrusion segmentation along time sequences. Volumetric shapes are clustered in an embedding space, clusters are propagated in time to ensure coherence, and merged or split to accommodate changes in the body's topology. Experiments on both synthetic and real sequences of dense voxel-set data are shown. This supports the ability of the proposed method to cluster body-parts consistently over time in a totally unsupervised fashion, its robustness to sampling density and shape quality, and its potential for bottom-up model constructionComment: 31 pages, 26 figure

    Sixth annual conference on alaskan placer mining

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    An abridged format of papers, presentations and addresses given during the 1984 conference held on March 28-29, 1984, compiled and edited by Daniel E. Walsh and M. Susan Wray

    Diagnosing Anencephaly In Archaeology: A Comparative Analysis Of Nine Clinical Specimens From The Smithsonian Institution Nation

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    The inclusion of human fetal skeletons in the archaeological record can reveal much about past cultures\u27 perception of life and death. The preservation of fetal remains in the archaeological record is a rarity, and the discovery of pathological skeletons is even rarer. A fetal skeleton from a Roman period cemetery (c. 31BC - 303AD) in the Dakhleh Oasis, Egypt, displays what are thought to be classic skeletal indicators of the neural tube defect, anencephaly. The published literature concerning the skeletal diagnosis of anencephaly is scant so in order to diagnose this individual it is pertinent to create a diagnostic standard. The purpose of this thesis is twofold - first to create a quantitative standard from which researchers can determine the presence of anencephaly in the archaeological record, thus ruling out trauma or taphonomic processes as reasons for missing cranial elements. The second objective of this research is to conduct a qualitative comparison in order to diagnose the individual from the Dakhleh Oasis. A comparative analysis of nine documented anencephalic skeletal remains housed at the Smithsonian Institute was conducted to create a diagnostic standard for the skeletal characteristics of anencephaly. The comparative analysis of the Dakhleh specimen supports the diagnosis of anencephaly

    Comparative sedimentology and paleoecology of fossil giant oyster beds in some tertiary strata of New Zealand and Argentina

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    Shell concentrations are useful indicators of relative sea-level changes, systems tracts, and depositional sequence and boundary surfaces. Shellbeds can equally act as archives of paleoenvironmental information and aid in the reconstruction of past environmental and ecological conditions. These considerations are applied in this study to occurrences of giant oyster reefs and shellbeds in Tertiary sequences in North Island, New Zealand, and in Patagonia, southern Argentina. Large recliner morphotype Flemingostreini Stenzel oysters are common in the Oligocene Orahiri Limestone in the vicinity of Waitomo, New Zealand. The oysters occur in tabular beds typically 0.5-2 m, but up to 9 m thick within highly indurated biomicritic limestone. Individual valves reach 15 cm in length, 10 cm in width and 2.5 to 5 cm in thickness. The occurences at Waitomo are characteristic of multi-event shellbeds and can be interpreted as onlap (transgressive lag) and backlap shellbeds within a transgressive systems tract. Shell delta18O (-2.1 to 1.4 per mille) and delta13C (0.4 and 2.5 per mille) values, and minimal seasonal isotopic ranges with little variability, confirm that these oysters lived in a fully marine environment. The environment of Oligocene Flemingstreini Stenzel was probably similar to modern Ostrea chilensis from Foveaux Strait off southern New Zealand, living on coarse shelly and gravelly tide swept substrates in 18-40 m water depth, under normal marine salinity conditions and temperatures around 13oC, forming in situ biostromes of haphazardly packed oyster shells. Specimens of Ostrea patagonica in the Late Miocene Puerto Madryn Formation, Pen nsula Vald s, Patagonia, are held in a weakly calcareous fine sand host. They reach 20 cm in length, 5 cm thick and weigh as much as 3 kg. The reef has a lens (or bioherm) geometry and is composed of articulated, well preserved oysters set in a fine sand matrix. The reef is interpreted as a downlap shellbed within a highstand systems tract. Oyster shell delta18O (-4.4 to -3.2 per mille) and delta13C (-2.0 to -3.2 per mille) values are low and show large seasonal isotopic ranges, with a large amount of variability, collectively supporting a marginal marine setting receiving extensive freshwater input and mixing. The environment of these oysters is comparable with modern Crassostrea gigas reefs at San Blas, Patagonia. Ostrea patagonica occupied a low energy intertidal zone in water depths of only 1-2 m. Temperatures ranged from 20degreesC (summer maximum) to 8degreesC (winter minimum). The oysters were not cemented firmly to the substrate, but reclined on the muddy sediment and formed an in situ bioherm of loosely packed oysters, with the living animals concentrated over time to the outside of the accumulation. The Pliocene Wilkies Shellbed in the Wanganui Basin, New Zealand, comprises oyster accumulations up to 15 m thick involving the extinct oyster Crassostrea ingens. Individuals are up to 30 cm long, 7 cm thick and weigh as much as 2 kg. The shellbed consists of a lower onlap shellbed (transgressive lag) and an overlying backlap shellbed (biostrome). The widespread shell delta18O (-3.0 to 3.0 per mille) and delta13C (-2.6 to 1.8 per mille) isotopic values support a range of marginal marine to marine environmental conditions. The lower onlap shellbed had estuarine influence, while the upper part had affinities with a nearshore (less than 40 m) marine setting of more normal salinity. As the thick backlap shellbed migrated shoreward a depth was maintained in which Crassostrea could live in situ within a weakly calcareous very fine muddy sand in favourable conditions of low turbidity and sedimentation. All species of fossil oysters in this study are easily distinguished by the large size and thickness of their valves. The 'reefs' formed by these oysters provided hard substrata for a diverse community of encrusting and boring organisms which includes the likes of Gastrochaenolites (bivalve), Maeandropolydora (polychaete), Clionolithes (boring algae), Entobia (sponge), Leptichnus (bryozoan) and Radulichnus (gastropod). These communities are comparable to those seen on extant oyster reefs. They can thus be termed autogenic ecosystem engineers. Non-random distribution of euendoliths and epiliths on oyster valves may be accounted for by different survival adaptations of larvae. Shell morphotypes and exterior architectures are inferred to have prompted active rugophilic (groove-seeking), geophobic (anti-gravity) and rheophilic (current-seeking) behaviour of larvae, which enhanced their survival rate. Preference for the external surface of shells suggests that traces were created during the life time of the oysters, while most internal traces are post-mortem features

    Sketch-Based Animation Tool for Character Animation Intergrating into a Production Pipeline

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    Creating appealing character poses can be time-consuming in an animation production pipeline incorporating skeletal-based character rigs. Animators utilize point-and- click input devices such as a mouse and keyboard to manipulate the character pose, rather than interacting intuitively as they would in a hand-drawn medium. This paper describes a sketch-based animation tool integrated into Autodesk Maya, enabling nondestructive and spatially accurate control over the animation of the line of action of arms, legs and spines. The tool provides a faster and more natural method for animators to pose and animate CG characters compared to mouse and keyboard input
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