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Smooth ViewDependent LevelofDetail Control and Its Application to Terrain Rendering
"... The key to realtime rendering of largescale surfaces is to locally adapt surface geometric complexity to changing view parameters. Several schemes have been developed to address this problem of viewdependent levelofdetail control. Among these, the viewdependent progressive mesh (VDPM) framewor ..."
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Cited by 215 (1 self)
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The key to realtime rendering of largescale surfaces is to locally adapt surface geometric complexity to changing view parameters. Several schemes have been developed to address this problem of viewdependent levelofdetail control. Among these, the viewdependent progressive mesh (VDPM) framework represents an arbitrary triangle mesh as a hierarchy of geometrically optimized refinement transformations, from which accurate approximating meshes can be efficiently retrieved. In this paper we extend the general VDPM framework to provide temporal coherence through the runtime creation of geomorphs. These geomorphs eliminate "popping" artifacts by smoothly interpolating geometry. Their implementation requires new outputsensitive data structures, which have the added benefit of reducing memory use.
Computing and Rendering Point Set Surfaces
, 2002
"... We advocate the use of point sets to represent shapes. We provide a definition of a smooth manifold surface from a set of points close to the original surface. The definition is based on local maps from differential geometry, which are approximated by the method of moving least squares (MLS). The co ..."
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Cited by 170 (21 self)
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We advocate the use of point sets to represent shapes. We provide a definition of a smooth manifold surface from a set of points close to the original surface. The definition is based on local maps from differential geometry, which are approximated by the method of moving least squares (MLS). The computation of points on the surface is local, which results in an outofcore technique that can handle any point set.
Geometry clipmaps: terrain rendering using nested regular grids
 In SIGGRAPH ’04: ACM SIGGRAPH 2004 Papers
, 2004
"... Illustration using a coarse geometry clipmap (size n=31) View of the 216,000×93,600 U.S. dataset near Grand Canyon (n=255) Figure 1:Terrains rendered using geometry clipmaps, showing clipmap levels (size n×n) and transition regions (in blue on right). Rendering throughput has reached a level that en ..."
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Cited by 95 (2 self)
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Illustration using a coarse geometry clipmap (size n=31) View of the 216,000×93,600 U.S. dataset near Grand Canyon (n=255) Figure 1:Terrains rendered using geometry clipmaps, showing clipmap levels (size n×n) and transition regions (in blue on right). Rendering throughput has reached a level that enables a novel approach to levelofdetail (LOD) control in terrain rendering. We introduce the geometry clipmap, which caches the terrain in a set of nested regular grids centered about the viewer. The grids are stored as vertex buffers in fast video memory, and are incrementally refilled as the viewpoint moves. This simple framework provides visual continuity, uniform frame rate, complexity throttling, and graceful degradation. Moreover it allows two new exciting realtime functionalities: decompression and synthesis. Our main dataset is a 40GB height map of the United States. A compressed image pyramid reduces the size by a remarkable factor of 100, so that it fits entirely in memory. This compressed data also contributes normal maps for shading. As the viewer approaches the surface, we synthesize grid levels finer than the stored terrain using fractal noise displacement. Decompression, synthesis, and normalmap computations are incremental, thereby allowing interactive flight at 60 frames/sec.
Perceptually Guided Simplification of Lit Textured Meshes
 In Proceedings of the 2003 symposium on Interactive 3D graphics
, 2003
"... We present a new algorithm for besteffort simplification of polygonal meshes based on principles of visual perception. Building on previous work, we use a simple model of lowlevel human vision to estimate the perceptibility of local simplification operations in a viewdependent MultiTriangulation ..."
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Cited by 34 (0 self)
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We present a new algorithm for besteffort simplification of polygonal meshes based on principles of visual perception. Building on previous work, we use a simple model of lowlevel human vision to estimate the perceptibility of local simplification operations in a viewdependent MultiTriangulation structure. Our algorithm improves on prior perceptual simplification approaches by accounting for textured models and dynamic lighting effects. We also model more accurately the scale of visual changes resulting from simplification, using parametric texture deviation to bound the size (represented as spatial frequency) of features destroyed, created, or altered by simplifying the mesh. The resulting algorithm displays many desirable properties: it is viewdependent, sensitive to silhouettes, sensitive to underlying texture content, and sensitive to illumination (for example, preserving detail near highlight and shadow boundaries, while aggressively simplifying washedout regions). Using a unified perceptual model to evaluate these effects automatically accounts for their relative importance and balances between them, overcoming the need for ad hoc or handttmed heuristics.
Variable Resolution Triangulations
, 1998
"... A comprehensive study of multiresolution decompositions of planar domains into triangles is given. A general model is introduced, called a MultiTriangulation (MT), which is based on a collection of fragments of triangulations arranged into a directed acyclic graph. Different decompositions of a dom ..."
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Cited by 33 (1 self)
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A comprehensive study of multiresolution decompositions of planar domains into triangles is given. A general model is introduced, called a MultiTriangulation (MT), which is based on a collection of fragments of triangulations arranged into a directed acyclic graph. Different decompositions of a domain can be obtained by combining different fragments of the model. Theoretical results on the expressive power of the MT are given. An efficient algorithm is proposed that can extract a triangulation from the MT, whose level of detail is variable over the domain according to a given threshold function. The algorithm works in linear time, and the extracted representation has minimum size among all possible triangulations that can be built from triangles in the MT, and that satisfy the given level of detail. Major applications of these results are in realtime rendering of complex surfaces, such as topographic surfaces in flight simulation. Keywords: multiresolution decomposition, triangulatio...
MultiResolution Dynamic Meshes with Arbitrary Deformations
 IN PROCEEDINGS OF THE CONFERENCE ON VISUALIZATION 2000
, 2000
"... Multiresolution techniques and models have been shown to be effective for the display and transmission of large static geometric object. Dynamic environments with internally deforming objects pose similar challenges in terms of time and space and need the development of similar solutions. We pres ..."
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Cited by 29 (3 self)
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Multiresolution techniques and models have been shown to be effective for the display and transmission of large static geometric object. Dynamic environments with internally deforming objects pose similar challenges in terms of time and space and need the development of similar solutions. We present the TDAG, an adaptive multiresolution representation for dynamic meshes with arbitrary deformations including attribute, position, connectivity and topology changes. We also provide an online algorithm for constructing the TDAG, enabling the traversal and use of the multiresolution model for partial playback while still constructing it.
QuickVDR: Interactive viewdependent rendering of massive models
 IEEE VISUALIZATION
, 2004
"... We present a novel approach for interactive viewdependent rendering of massive models. Our algorithm combines viewdependent simplification, occlusion culling, and outofcore rendering. We represent the model as a clustered hierarchy of progressive meshes (CHPM). We use the cluster hierarchy for c ..."
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Cited by 29 (7 self)
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We present a novel approach for interactive viewdependent rendering of massive models. Our algorithm combines viewdependent simplification, occlusion culling, and outofcore rendering. We represent the model as a clustered hierarchy of progressive meshes (CHPM). We use the cluster hierarchy for coarsegrained selective refinement and progressive meshes for finegrained local refinement. We present an outofcore algorithm for computation of a CHPM that includes cluster decomposition, hierarchy generation, and simplification. We make use of novel cluster dependencies in the preprocess to generate crackfree, drastic simplifications at runtime. The clusters are used for occlusion culling and outofcore rendering. We add a frame of latency to the rendering pipeline to fetch newly visible clusters from the disk and to avoid stalls. The CHPM reduces the refinement cost for viewdependent rendering by more than an order of magnitude as compared to a vertex hierarchy. We have implemented our algorithm on a desktop PC. We can render massive CAD, isosurface, and scanned models, consisting of tens or a few hundreds of millions of triangles at 10−35 frames per second with little loss in image quality.
Navigating through Triangle Meshes Implemented as Linear Quadtrees
 ACM Transactions on Graphics
, 1998
"... Techniques are presented for navigating between adjacent triangles of greater or equal size in a hierarchical triangle mesh where the triangles are obtained by a recursive quadtreelike subdivision of the underlying space into four equilateral triangles. These techniques are useful in a number of ap ..."
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Cited by 27 (1 self)
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Techniques are presented for navigating between adjacent triangles of greater or equal size in a hierarchical triangle mesh where the triangles are obtained by a recursive quadtreelike subdivision of the underlying space into four equilateral triangles. These techniques are useful in a number of applications including finite element analysis, ray tracing, and the modeling of spherical data. The operations are implemented in a manner analogous to that used in a quadtree representation of data on the twodimensional plane where the underlying space is tessellated into a square mesh. A new technique is described for labeling the triangles which is useful in implementing the quadtree triangle mesh as a linear quadtree (i.e., a pointerless quadtree); the navigation can then take place in this linear quadtree. When the neighbors are of equal size, the algorithms take constant time. The algorithms are very efficient, as they make use of just a few bit manipulation operations and can be impl...
Multiresolution Mesh Representation: Models and Data Structures
 Tutorials on Multiresolution in Geometric Modelling
, 2002
"... Multiresolution meshes are a common basis for building representations of a geometric shape at dierent levels of detail. The use of the term multiresolution depends on the remark that the accuracy (or, level of detail) of a mesh in approximating a shape is related to the mesh resolution, i.e., to t ..."
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Cited by 24 (17 self)
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Multiresolution meshes are a common basis for building representations of a geometric shape at dierent levels of detail. The use of the term multiresolution depends on the remark that the accuracy (or, level of detail) of a mesh in approximating a shape is related to the mesh resolution, i.e., to the density (size and number) of its cells. A multiresolution mesh provides several alternative meshbased approximations of a spatial object (e.g., a surface describing the boundary of a solid object, or the graph of a scalar eld).
Applications of Computational Geometry to Geographic Information Systems
"... Contents 1 Introduction 2 2 Map Data Modeling 4 2.1 TwoDimensional Spatial Entities and Relationships . . . . . . . . . . . . . . . . . . . . . 4 2.2 Raster and Vector Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3 Subdivisions as Cell Complexes . . . . . . . ..."
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Cited by 21 (1 self)
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Contents 1 Introduction 2 2 Map Data Modeling 4 2.1 TwoDimensional Spatial Entities and Relationships . . . . . . . . . . . . . . . . . . . . . 4 2.2 Raster and Vector Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3 Subdivisions as Cell Complexes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.4 Topological Data Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.5 Multiresolution Data Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3 Map data processing 8 3.1 Spatial Queries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.2 Map Overlay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.3 Geometric Problems in Map Generalization . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.4 Map Labeling . . . . . . . . . . . . . . . . . . . . . . . . . . .