Papers by Szymon Rusinkiewicz
Abstract Line drawings can convey shape using remarkably minimal visual content. Suggestive conto... more Abstract Line drawings can convey shape using remarkably minimal visual content. Suggestive contours, which are lines drawn at certain types of view-dependent surface inflections, were proposed recently as a way of improving the effectiveness of computer-generated line drawings. This paper extends previous work on static suggestive contours to dynamic and real-time settings.
Abstract The digitization of the 3D shape of real objects is a rapidly expanding field, with appl... more Abstract The digitization of the 3D shape of real objects is a rapidly expanding field, with applications in entertainment, design, and archaeology. We propose a new 3D model acquisition system that permits the user to rotate an object by hand and see a continuously-updated model as the object is scanned. This tight feedback loop allows the user to find and fill holes in the model in real time, and determine when the object has been completely covered. Our system is based on a 60 Hz.
We explore the implications of reversing the process of shadow computation for real-time applicat... more We explore the implications of reversing the process of shadow computation for real-time applications that model complex reflectance and lighting (such as that specified by an environment map). Instead of adding illumination contributions at each pixel across various lights, we compute the complete, unshadowed local illumination at each pixel using approximations, then subtract the lighting contribution from each light for which the pixel is in shadow.
Abstract Recent work has shown that sparse lines defined on 3D shapes, including occluding contou... more Abstract Recent work has shown that sparse lines defined on 3D shapes, including occluding contours and suggestive contours, are effective at conveying shape. We introduce two new families of lines called suggestive highlights and principal highlights, based on definitions related to suggestive contours and geometric creases. We show that when these are drawn in white on a gray background they are naturally interpreted as highlight lines, and complement contours and suggestive contours.
Abstract Computing reflective symmetries of 2D and 3D shapes is a classical problem in computer v... more Abstract Computing reflective symmetries of 2D and 3D shapes is a classical problem in computer vision and computational geometry. Most prior work has focused on finding the main axes of symmetry, or determining that none exists. In this paper we introduce a new reflective symmetry descriptor that represents a measure of reflective symmetry for an arbitrary 3D model for all planes through the model's center of mass (even if they are not planes of symmetry).
Abstract We present a nonrigid alignment algorithm for aligning high-resolution range data in the... more Abstract We present a nonrigid alignment algorithm for aligning high-resolution range data in the presence of low-frequency deformations, such as those caused by scanner calibration error. Traditional iterative closest points (ICP) algorithms, which rely on rigid-body alignment, fail in these cases because the error appears as a nonrigid warp in the data.
Abstract We present a multiple-feature approach for determining matches between small fragments o... more Abstract We present a multiple-feature approach for determining matches between small fragments of archaeological artifacts such as Bronze-Age and Roman frescoes. In contrast with traditional 2D and 3D shape matching approaches, we introduce a set of feature descriptors that are based on not only color and shape, but also normal maps. These are easy to acquire and combine high data quality with discriminability and robustness to some types of deterioration.
Abstract This paper presents the results of a study in which artists made line drawings intended ... more Abstract This paper presents the results of a study in which artists made line drawings intended to convey specific 3D shapes. The study was designed so that drawings could be registered with rendered images of 3D models, supporting an analysis of how well the locations of the artists' lines correlate with other artists', with current computer graphics line definitions, and with the underlying differential properties of the 3D surface.
Abstract We introduce a layered, heterogeneous spectral reflectance model for human skin. The mod... more Abstract We introduce a layered, heterogeneous spectral reflectance model for human skin. The model captures the inter-scattering of light among layers, each of which may have an independent set of spatially-varying absorption and scattering parameters. For greater physical accuracy and control, we introduce an infinitesimally thin absorbing layer between scattering layers. To obtain parameters for our model, we use a novel acquisition method that begins with multi-spectral photographs.
Computing correspondences in geometric data sets
abstract={Shape registration and, more generally speaking, computing correspondence across shapes... more abstract={Shape registration and, more generally speaking, computing correspondence across shapes are fundamental problems in computer graphics and vision. Problems from this area show up in many different variants such as scan registration, deformable shapematching, animation reconstruction, or finding partial symmetries of objects.
Abstract It is possible to compare the masses of single ions with an accuracy of one part in 1011... more Abstract It is possible to compare the masses of single ions with an accuracy of one part in 1011 (an order of magnitude better than the current state of the art) by comparing the cyclotron frequencies of two ions of different species confined simultaneously in a Penning trap. Computer simulations were used to study the motion of two simultaneously trapped ions in a trap with predicted, partially controllable, imperfections; the results were checked against theoretical predictions for ideal Penning traps.
A system for high-volume acquisition and matching of fresco fragments: Reassembling Theran wall paintings
Abstract Although mature technologies exist for acquiring images, geometry, and normals of small ... more Abstract Although mature technologies exist for acquiring images, geometry, and normals of small objects, they remain cumbersome and time-consuming for non-experts to employ on a large scale. In an archaeological setting, a practical acquisition system for routine use on every artifact and fragment would open new possibilities for archiving, analysis, and dissemination.
Abstract Computational highlight holography converts three-dimensional computer models into mecha... more Abstract Computational highlight holography converts three-dimensional computer models into mechanical" holograms" fabricated on (specular) reflective or refractive materials. The surface consists of small grooves with patches of paraboloids or hyperboloids, each of which produces a highlight when illuminated by a directional light. Each highlight appears in different places for different view directions, with the correct binocular and motion parallax corresponding to a virtual 3D point position.
Abstract We present a new image-based technique for enhancing the shape and surface details of an... more Abstract We present a new image-based technique for enhancing the shape and surface details of an object. The input to our system is a small set of photographs taken from a fixed viewpoint, but under varying lighting conditions. For each image we compute a multiscale decomposition based on the bilateral filter and then reconstruct an enhanced image that combines detail information at each scale across all the input images.
Abstract We introduce a theoretical framework and practical algorithms for replacing time-coded s... more Abstract We introduce a theoretical framework and practical algorithms for replacing time-coded structured light patterns with viewpoint codes, in the form of additional camera locations. Current structured light methods typically use log (N) light patterns, encoded over time, to unambiguously reconstruct N unique depths. We demonstrate that each additional camera location may replace one frame in a temporal binary code.
Abstract We describe a hardware and software system for digitizing the shape and color of large f... more Abstract We describe a hardware and software system for digitizing the shape and color of large fragile objects under non-laboratory conditions. Our system employs laser triangulation rangefinders, laser time-of-flight rangefinders, digital still cameras, and a suite of software for acquiring, aligning, merging, and viewing scanned data.
Abstract Many translucent materials exhibit heterogeneous subsurface scattering, which arises fro... more Abstract Many translucent materials exhibit heterogeneous subsurface scattering, which arises from complex internal structures. The acquisition and representation of these scattering functions is a complex problem that has been only partially addressed in previous techniques. Unlike homogeneous materials, the spatial component of heterogeneous subsurface scattering can vary arbitrarily over surface locations. Storing the spatial component without compression leads to impractically large datasets.
Abstract. This research and educational project aimed to create virtual 3-D walkthroughs of four ... more Abstract. This research and educational project aimed to create virtual 3-D walkthroughs of four principal buildings from the Princeton University excavations at Polis Chrysochous, Cyprus. The structures date from the Cypro-Archaic period beginning in the 7th century BCE to the Late Antique period of the 7th century CE. The project was conceived together with a special exhibition, a long-term exhibition in Cyprus, and a presentation on the web.
Abstract A key challenge in reconstructing high-quality 3D scans is registering data from differe... more Abstract A key challenge in reconstructing high-quality 3D scans is registering data from different viewpoints. Existing global (multiview) alignment algorithms are restricted to rigid-body transformations, and cannot adequately handle non-rigid warps frequently present in real-world datasets. Moreover, algorithms that can compensate for such warps between pairs of scans do not easily generalize to the multiview case.
Abstract Steady growth in the speeds of network links and graphics accelerator cards has brought ... more Abstract Steady growth in the speeds of network links and graphics accelerator cards has brought increasing interest in streaming transmission of three-dimensional data sets. We demonstrate how streaming visualization can be made practical for data sets containing hundreds of millions of samples. Our system is based on QSplat, a multiresolution rendering system for dense polygon meshes that employs a bounding sphere hierarchy data structure and splat rendering.
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Papers by Szymon Rusinkiewicz