. In this paper, an approach for integrating multiresolution representations of terrain geometry and terrain texture data is presented. A terrain is modeled by a regular grid, which can be partially refined by local TINs in order to represent morphologically complex terrain parts. The multiresolution models for terrain texture data and geometry data are closely related: The rendering algorithm selects geometry and texture patches based on screen-space error criteria. Multiple texture hierarchies, which may represent different thematic information layers, can be bound to one terrain model. Multiple textures lead to a drastic improvement of visual quality: Topographic textures can be used to provide pixel-precise shading, alpha textures can be used to restrict or to highlight thematic textures. Multiple textures facilitate the development of visual interaction tools such as magic lenses, and texture animations. Multitexturing permits an efficient implementation of these conce...

A color image with an associated normal stored for each pixel is a useful datatype. It improves on images since geometry information is also present while at the same time it avoids all the complexity present in a 3D mesh. In this report, we investigate editing these enhanced images. Local shape deformation operators are presented. Global operators are developed using texture synthesis methods. We also propose a new ltering technique.

Cultural Heritage scenes usually consist of very large and detailed 3D objects with high geometric complexity. Even the raw visualization of such 3D objects already involves a large amount of memory and computation time. When trying to improve the sense of immersion and realism by using, global illumination techniques the demand on these resources becomes prohibitive. Our approach uses regular grids combined with a vector-based representation to efficiently capture low-frequency indirect illumination. A fixed set of irradiance vectors is stored in 3D textures (for complex objects) and in 2D textures (for mostly planar objects). The vector-based representation offers additional robustness against local variations of the geometry. Consequently, the grid resolution can be set independently of geometric complexity, and the memory footprint can therefore be reduced. The irradiance vectors can be precomputed on a simplified geometry. For interactive rendering, we use an appearance-preserving simplification of the geometry. The indirect illumination within a grid cell is interpolated from its associated irradiance vectors, resulting in an everywheresmooth reconstruction.

Automatic simplification of polyhedral objects is a major topic in many computer graphics applications. In this work, simplification algorithms for the generation of a multiresolution family of solid representations from an initial polyhedral solid are discussed. We introduce the Discretized Polyhedra Simplification (DPS), a framework for polyhedra simplification using space decomposition models. DPS is based on a new error distance and provides a sound scheme for error-bounded, geometry and topology simplification while preserving the validity of the model. A method following this framework, trihedral DPS, is presented and discussed. Trihedral DPS uses an octree for topology simplification and error control, and generates valid solid representations. Our method is also able to generate approximations that do not interpenetrate the original model, either being completely contained in the input solid or bounding it. Unlike most of the current methods, restricted to triangle meshes, our ...

this paper is a new multiresolution texture atlas. It distributes all available texture samples in a nearly uniform distribution. This multiresolution texture atlas is the first of its kind to fully support MIP-mapped minification antialiasing and linear magnification filtering

This paper presents an efficient hardware-accelerated method for novel view synthesis from a set of images or videos. Our method is based on the photo hull representation, which is the maximal photo-consistent shape. We avoid the explicit reconstruction of photo hulls by adopting a view-dependent plane-sweeping strategy. From the target viewpoint slicing planes are rendered with reference views projected onto them. Graphics hardware is exploited to verify the photo-consistency of each rasterized fragment. Visibilities with respect to reference views are properly modeled, and only photo-consistent fragments are kept and colored in the target view. We present experiments with real images and animation sequences. Thanks to the more accurate shape of the photo hull representation, our method generates more realistic rendering results than methods based on visual hulls. Currently, we achieve rendering frame rates of 2-3 fps. Compared to a pure software implementation, the performance of our hardware-accelerated method is approximately 7 times faster.

Texturing using a set of two dimensional image maps is an established and widespread practice. However, it has many limitations. Parameterizing a model in texture space can be very difficult, particularly with representations such as implicit surfaces, subdivision surfaces, and very dense or detailed polygonal meshes. This paper proposes the use of a new kind of texture based on an octree, which needs no parameterization other than the surface itself, and yet has similar storage requirements to 2D maps. In addition, it offers adaptive detail, regular sampling over the surface, and continuity across surface boundaries. The paper addresses texture creation, painting, storage, processing, and rendering with octree textures.

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Abstract—Both texture maps and procedural shaders suffer from rendering artifacts during minification. Unlike texture maps, there exist no good automatic method to antialias procedural shaders. Given a procedural shader for a surface, we present a method that automatically creates an antialiased version of the procedural shader. The new procedural shader maintains the original shader’s details but reduces artifacts (aliasing or noise) due to minification. This new algorithm creates a pyramid similar to a MIP-Map in order to represent the shader. Instead of storing per-texel color, pyramid stores weighted sums of reflectance functions, allowing a wider range of effects to be antialiased. The stored reflectance functions are automatically selected based on an analysis of the different reflectances found over the surface. When the rendered surface is viewed at close range, the original shader is used, but as the texture footprint grows, the algorithm gradually replaces the shader’s result with an antialiased one. Index Terms—Antialiasing, texture, procedural shader, surface normal distribution. Ç

Abstract—We propose a method to edit RGBNs (images with a color and a normal channel). High resolution RGBNs are easy to obtain using photometric stereo. Free editing will result in normals which do not correspond to any realizable surface. Our normal operators guarantee the integrability of the results. Our method can filter normals with any linear kernel allowing high-pass and edge-enhancement filters. We have designed a normal linear combination method for adding details with frequency control. New geometric features can be created with a custom brush that warps deformations along its path. A nonlinear operator is also proposed. Its integrability is controlled with a two-band separation of frequencies: smooth shape and details. Keywords-RGBN, normal map, gradient reconstruction, normal processing, filtering, deformation I.