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Item Editorial(Blackwell Publishers Ltd and the Eurographics Association, 1997) Coquillart, Sabine; Seidel, Hans-PeterItem Editorial(Blackwell Publishers Ltd and the Eurographics Association, 1997) Seidel, Hans-Peter; Coquillart, SabineItem Using Subdivision on Hierarchical Data to Reconstruct Radiosity Distribution(Blackwell Publishers Ltd and the Eurographics Association, 1997) Kobbelt, Leif; Stamminger, Marc; Seidel, Hans-PeterComputing global illumination by finite element techniques usually generates a piecewise constant approximation of the radiosity distribution on surfaces. Directly displaying such scenes generates artefacts due to discretization errors. We propose to remedy this drawback by considering the piecewise constant output to be samples of a (piecewise) smooth function in object space and reconstruct this function by applying a binary subdivision scheme. We design custom taylored subdivision schemes with quadratic precision for the efficient refinement of cell- or pixel-type data. The technique naturally allows to reconstruct functions from non-uniform samples which result from adaptive binary splitting of the original domain (quadtree). This type of output is produced, e.g., by hierarchical radiosity algorithms. The result of the subdivision process can be mapped as a texture on the respective surface patch which allows to exploit graphics hardware for considerably accelerating the display.Item Editorial(Blackwell Publishers Ltd and the Eurographics Association, 1997) Coquillart, Sabine; Seidel, Hans-PeterItem Bounded Radiosity - Illumination on General Surfaces and Clusters(Blackwell Publishers Ltd and the Eurographics Association, 1997) Stamminger, Marc; Slusallek, Philipp; Seidel, Hans-PeterTraditionally, Radiosity algorithms have been restricted to scenes made from planar patches. Most algorithms for computing form factors and the subdivision criterion for hierarchical methods implicitly assume planar patches. In this paper, we present a new radiosity algorithm that is solely based on simple geometric information about surface elements, namely their bounding boxes and cone of normals. Using this information allows to compute efficient error bounds that can be used for the subdivision oracle and for computing the energy transfer. Due to the simple interface to geometric objects, our algorithm not only allows for computing illumination on general curved surfaces, but it can also be directly applied to a hieararchy of clusters. Several examples demonstrate the advantages of the new approach.Item Editorial(Blackwell Publishers Ltd and the Eurographics Association, 1997) Coquillart, Sabine; Seidel, Hans-Peter