User-assisted mesh simplification

During the last decade, many simplification methods have been proposed to generate multi-resolution meshes for real-time applications. Practitioners have found that these methods alone usually fail to produce satisfactory result when models of very low polygon count are desired. This is due to the fact that the existing methods take no semantic or functional metric into account, and moreover, each error metric has its own strength and weakness. In this paper, we propose a user-assisted mesh simplification framework that allows users to improve the quality of simplified meshes derived by any error metric. The framework consists of two stages. The first stage employs a weighting scheme that allows users to refine a unsatisfactory region to achieve a user-specified resolution. The second stage is a local refinement scheme aiming to provide a user-guided fine-tune to recover local sharp features. The proposed weighting scheme differs from the previous approaches in that the weights are used to directly reorder the edge collapsing sequence rather than weighting the collapsing cost. Such a direct reordering mechanism ensures a predictable increase of resolution in the selected region, and is both error-metric and resolution independent.