Ilic Slobodan, Fua Pascal
Ecole Polytechnique Fédérale de Lausanne (EPFL), Computer Vision Laboratory, CH-1015 Lausanne, Switzerland.
IEEE Trans Pattern Anal Mach Intell. 2006 Feb;28(2):328-33. doi: 10.1109/TPAMI.2006.37.
Deformable 3D models can be represented either as traditional explicit surfaces, such as triangulated meshes, or as implicit surfaces. Explicit surfaces are widely accepted because they are simple to deform and render, but fitting them involves minimizing a nondifferentiable distance function. By contrast, implicit surfaces allow fitting by minimizing a differentiable algebraic distance, but are harder to meaningfully deform and render. Here, we propose a method that combines the strength of both approaches. It relies on a technique that can turn a completely arbitrary triangulated mesh, such as one taken from the Web, into an implicit surface that closely approximates it and can deform in tandem with it. This allows both automated algorithms to take advantage of the attractive properties of implicit surfaces for fitting purposes and people to use standard deformation tools they feel comfortable for interaction and animation purposes. We demonstrate the applicability of our technique to modeling the human upper-body, including face, neck, shoulders, and ears, from noisy stereo and silhouette data.
可变形三维模型既可以表示为传统的显式曲面，如三角网格，也可以表示为隐式曲面。显式曲面被广泛接受，因为它们易于变形和渲染，但拟合它们需要最小化一个不可微的距离函数。相比之下，隐式曲面允许通过最小化一个可微的代数距离来进行拟合，但更难进行有意义的变形和渲染。在这里，我们提出了一种结合两种方法优点的方法。它依赖于一种技术，该技术可以将一个完全任意的三角网格，比如从网上获取的网格，转化为一个与之紧密近似且能与之同步变形的隐式曲面。这使得自动化算法能够利用隐式曲面的诱人特性进行拟合，同时人们也能够使用他们熟悉的标准变形工具进行交互和动画制作。我们展示了我们的技术在从有噪声的立体和轮廓数据对包括面部、颈部、肩部和耳朵在内的人体上半身进行建模方面的适用性。
