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Although deforming surfaces are frequently used in numerous domains, only few works have been proposed until now for simplifying such data. In this paper, we propose a new method for generating progressive deforming meshes based on shape feature analysis and deformation area preservation. By computing the curvature and torsion of each vertex in the original model, we add the shape feature factor to its quadric error metric when calculating each QEM edge collapse cost. In order to preserve the areas with large deformation, we add deformation degree weight to the aggregated quadric errors when computing the unified edge contraction sequence. Finally, the edge contraction order is slightly adjusted to further reduce the geometric distortion for each frame. Our approach is fast, easy to implement, and as a result good quality dynamic approximations with well-preserved fine details can be generated at any given frame. [ABSTRACT FROM AUTHOR]

In order to provide a streaming service of 3-D spatial objects to the mobile clients on a street, we propose a new query type, called continuous perspective query. The perspective query differs from conventional spatial queries in that the levels of details (LOD) of query results depend on the distance between the query point and spatial objects. The objects in the vicinity are to be provided with a higher LOD than those far from the query point. We are dealing with continuous queries, and the LODs of the results are also changing according to the distance from the mobile query point. The LOD of the result object changes from a low LOD to a high LOD as the mobile query point approaches to the object. In this paper, we also propose a processing method for continuous perspective query to reduce the processing cost at a server and communication cost between the server and the mobile clients. [ABSTRACT FROM AUTHOR]