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38
ShapeShop: SketchBased Solid Modeling with BlobTrees
, 2005
"... Various systems have explored the idea of inferring 3D models from sketched 2D outlines. In all of these systems the underlying modeling methodology limits the complexity of models that can be created interactively. The ShapeShop sketchbased modeling system utilizes Hierarchical Implicit Volume M ..."
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Cited by 53 (15 self)
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Various systems have explored the idea of inferring 3D models from sketched 2D outlines. In all of these systems the underlying modeling methodology limits the complexity of models that can be created interactively. The ShapeShop sketchbased modeling system utilizes Hierarchical Implicit Volume Models (BlobTrees) as an underlying shape representation. The BlobTree framework supports interactive creation of complex, detailed solid models with arbitrary topology. A new technique is described for inflating 2D contours into rounded threedimensional implicit volumes. Sketchbased modeling operations are defined that combine these basic shapes using standard blending and CSG operators. Since the underlying volume hierarchy is by definition a construction history, individual sketched components can be nonlinearly edited and removed. For example, holes can be interactively dragged through a shape. ShapeShop also provides 2D drawing assistance using a new curvesketching system based on variational contours. A wide range of models can be sketched with ShapeShop, from cartoonlike characters to detailed mechanical parts. Examples are shown which demonstrate significantly higher model complexity than existing systems.
Dual Marching Cubes: Primal Contouring of Dual Grids
 IN PG ’04: PROCEEDINGS OF THE COMPUTER GRAPHICS AND APPLICATIONS, 12TH PACIFIC CONFERENCE ON (PG’04
, 2004
"... We present a method for contouring an implicit function using a grid topologically dual to structured grids such as octrees. By aligning the vertices of the dual grid with the features of the implicit function, we are able to reproduce thin features without excessive subdivision required by methods ..."
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Cited by 40 (5 self)
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We present a method for contouring an implicit function using a grid topologically dual to structured grids such as octrees. By aligning the vertices of the dual grid with the features of the implicit function, we are able to reproduce thin features without excessive subdivision required by methods such as Marching Cubes or Dual Contouring. Dual Marching Cubes produces a crackfree, adaptive polygonalization of the surface that reproduces sharp features. Our approach maintains the advantage of using structured grids for operations such as CSG while being able to conform to the relevant features of the implicit function yielding much sparser polygonalizations than has been possible using structured grids.
Accurate Minkowski Sum Approximation of Polyhedral Models
 In Pacific Conference on Computer Graphics and Applications
, 2004
"... We present an algorithm to approximate the 3D Minkowski sum of polyhedral objects. Our algorithm decomposes the polyhedral objects into convex pieces, generates pairwise convex Minkowski sums and computes their union. We approximate the union by generating a voxel grid, computing signed distance on ..."
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Cited by 30 (3 self)
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We present an algorithm to approximate the 3D Minkowski sum of polyhedral objects. Our algorithm decomposes the polyhedral objects into convex pieces, generates pairwise convex Minkowski sums and computes their union. We approximate the union by generating a voxel grid, computing signed distance on the grid points and performing isosurface extraction from the distance field.
Robust feature classification and editing
 IEEE Trans. Visualization and Computer Graphics
"... Abstract—Sharp edges, ridges, valleys, and prongs are critical for the appearance and an accurate representation of a 3D model. In this paper, we propose a novel approach that deals with the global shape of features in a robust way. Based on a remeshing algorithm which delivers an isotropic mesh in ..."
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Cited by 19 (7 self)
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Abstract—Sharp edges, ridges, valleys, and prongs are critical for the appearance and an accurate representation of a 3D model. In this paper, we propose a novel approach that deals with the global shape of features in a robust way. Based on a remeshing algorithm which delivers an isotropic mesh in a featuresensitive metric, features are recognized on multiple scales via integral invariants of local neighborhoods. Morphological and smoothing operations are then used for feature region extraction and classification into basic types such as ridges, valleys, and prongs. The resulting representation of feature regions is further used for featurespecific editing operations.
FeatureSensitive Subdivision and Isosurface Reconstruction
 IN IEEE VISUALIZATION 2003
, 2003
"... We present improved subdivision and isosurface reconstruction algorithms for polygonizing implicit surfaces and performing accurate geometric operations. Our improved reconstruction algorithm uses directed distance fields [Kobbelt et al. 2001] to detect multiple intersections along an edge, separate ..."
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Cited by 19 (5 self)
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We present improved subdivision and isosurface reconstruction algorithms for polygonizing implicit surfaces and performing accurate geometric operations. Our improved reconstruction algorithm uses directed distance fields [Kobbelt et al. 2001] to detect multiple intersections along an edge, separates them into components and reconstructs an isosurface locally within each component using the dual contouring algorithm [Ju et al. 2002]. It can reconstruct thin features without creating handles and results in improved surface extraction from volumetric data. Our subdivision
Dynamic Remeshing and Applications
 Department, Stony Brook University. Her
, 2003
"... Triangle meshes are a flexible and generally accepted boundary representation for complex geometric shapes. In addition to their geometric qualities and topological simplicity, intrinsic qualities such as the shape of the triangles, their distribution on the surface and the connectivity are essentia ..."
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Cited by 17 (4 self)
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Triangle meshes are a flexible and generally accepted boundary representation for complex geometric shapes. In addition to their geometric qualities and topological simplicity, intrinsic qualities such as the shape of the triangles, their distribution on the surface and the connectivity are essential for many algorithms working on them. In this paper we present a flexible and efficient remeshing framework that improves these intrinsic properties while keeping the mesh geometrically close to the original surface. We use a particle system approach and combine it with an incremental connectivity optimization process to trim the mesh towards the requirements imposed by the user. The particle system uniformly distributes the vertices on the mesh, whereas the connectivity optimization is done by means of Dynamic Connectivity Meshes, a combination of local topological operators that lead to a fairly regular connectivity. A dynamic skeleton ensures that our approach is able to preserve surface features, which are particularly important for the visual quality of the mesh. None of the algorithms requires a global parameterization or patch layouting in a preprocessing step but uses local parameterizations only. We also show how this general framework can be put into practice and sketch several application scenarios. In particular we will show how the users can adapt the involved algorithms in a way that the resulting remesh meets their personal requirements.
An ImplicitBased Haptic Rendering Technique
 In Proceeedings of the IEEE/RSJ International Conference on Intelligent Robots
, 2002
"... We present a novel haptic rendering technique. Based on previous work, we propose a haptic model based on a volumetric description of the geometry of an object. Unlike previous volumetric approaches, we also find a virtual contact point on the surface in order to derive a penalty force that is consi ..."
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Cited by 15 (1 self)
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We present a novel haptic rendering technique. Based on previous work, we propose a haptic model based on a volumetric description of the geometry of an object. Unlike previous volumetric approaches, we also find a virtual contact point on the surface in order to derive a penalty force that is consistent with the real geometry of the object, without introducing force discontinuity. We also demonstrate that other surface properties such as friction and texture can be added elegantly. The resulting technique is fast(a constant 1000 Hz refresh rate) and can handle large geometry models on lowend computers.
Streaming simplification of tetrahedral meshes
 IEEE Transactions on Visualization and Computer Graphics
, 2005
"... Abstract—Unstructured tetrahedral meshes are commonly used in scientific computing to represent scalar, vector, and tensor fields in three dimensions. Visualization of these meshes can be difficult to perform interactively due to their size and complexity. By reducing the size of the data, we can ac ..."
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Cited by 13 (6 self)
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Abstract—Unstructured tetrahedral meshes are commonly used in scientific computing to represent scalar, vector, and tensor fields in three dimensions. Visualization of these meshes can be difficult to perform interactively due to their size and complexity. By reducing the size of the data, we can accomplish realtime visualization necessary for scientific analysis. We propose a twostep approach for streaming simplification of large tetrahedral meshes. Our algorithm arranges the data on disk in a streaming, I/Oefficient format that allows coherent access to the tetrahedral cells. A quadricbased simplification is sequentially performed on small portions of the mesh incore. Our output is a coherent streaming mesh which facilitates future processing. Our technique is fast, produces high quality approximations, and operates outofcore to process meshes too large for main memory. Index Terms—Computational geometry and object modeling, outofcore algorithms, streaming algorithms, mesh simplification, large meshes, tetrahedral meshes. 1
Dual contouring with topologypreserving simplification using enhanced cell representation
 in VIS ’04: Proceedings of the conference on Visualization ’04
, 2004
"... Figure 1: Simplifying the zeroisosurface of a directed distance volume of 256 3 using our topologypreserving isosurface simplification algorithm. Although the cylinders and the box are very close to each other, they don’t touch, and thus there are several disconnected surface components in this vo ..."
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Cited by 13 (1 self)
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Figure 1: Simplifying the zeroisosurface of a directed distance volume of 256 3 using our topologypreserving isosurface simplification algorithm. Although the cylinders and the box are very close to each other, they don’t touch, and thus there are several disconnected surface components in this volume. Note that disconnected surface components are assigned different materials and are clustered independently. (a) δ 2 = 0 and t = 97K. (b)δ 2 = 10 −6 and t = 23K. (c)δ 2 = 10 −4 and t = 2494. (δ 2: quadric error threshold, t: triangle count.) We present a fast, topologypreserving approach for isosurface simplification. The underlying concept behind our approach is to preserve the disconnected surface components in cells during isosurface simplification. We represent isosurface components in a novel representation, called enhanced cell, where each surface component in a cell is represented by a vertex and its connectivity information. A topologypreserving vertex clustering algorithm is applied to build a vertex octree. An enhanced dual contouring algorithm is applied to extract errorbounded multiresolution isosurfaces from the vertex octree while preserving the finest resolution isosurface topology. Cells containing multiple vertices are properly handled during contouring. Our approach demonstrates better results than existing octreebased simplification techniques.
Manifold dual contouring
 IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS
, 2007
"... Dual Contouring (DC) is a featurepreserving isosurfacing method that extracts crackfree surfaces from both uniform and adaptive octree grids. We present an extension of DC that further guarantees that the mesh generated is a manifold even under adaptive simplification. Our main contribution is an ..."
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Cited by 11 (2 self)
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Dual Contouring (DC) is a featurepreserving isosurfacing method that extracts crackfree surfaces from both uniform and adaptive octree grids. We present an extension of DC that further guarantees that the mesh generated is a manifold even under adaptive simplification. Our main contribution is an octreebased topologypreserving vertexclustering algorithm for adaptive contouring. The contoured surface generated by our method contains only manifold vertices and edges, preserves sharp features, and possesses much better adaptivity than those generated by other isosurfacing methods under topologically safe simplification.