This paper proposes a method to estimate the locations of grid handles in free-form deformation (FFD) while preserving the local shape characteristics of the 2D/3D input model embedded into the grid, named locality-preserving FFD (lp-FFD). Users first specify some vertex locations in the input model and grid handle locations. The system then optimizes all locations of grid handles by minimizing the distortion of the input model's mesh elements. The proposed method is fast and stable, allowing the user to directly and indirectly make the deformed shape of mesh model and grid. This paper shows some examples of deformation results to demonstrate the robustness of our lp-FFD. In addition, we conducted a user study and confirm our lp-FFD's efficiency and effectiveness in shape deformation is higher than those of existing methods used in commercial software.

翻译：本文提出一种在保持嵌入网格的二维/三维输入模型局部形状特征的同时，估计自由变形（FFD）中网格控制点位置的方法，命名为保持局部性的自由变形（lp-FFD）。用户首先指定输入模型中若干顶点位置及网格控制点位置，随后系统通过最小化输入模型网格单元的畸变，优化所有网格控制点的位置。该方法快速且稳定，使用户能够直接或间接地使网格模型与网格的变形形状符合预期。本文通过若干变形结果示例展示了lp-FFD的鲁棒性。此外，我们进行了用户研究，证实了lp-FFD在形状变形中的效率与有效性均优于现有商业软件中使用的既有方法。