Simulation of human soft tissues in contact with their environment is essential in many fields, including visual effects and apparel design. Biological tissues are nearly incompressible. However, standard methods employ compressible elasticity models and achieve incompressibility indirectly by setting Poisson's ratio to be close to 0.5. This approach can produce results that are plausible qualitatively but inaccurate quantatively. This approach also causes numerical instabilities and locking in coarse discretizations or otherwise poses a prohibitive restriction on the size of the time step. We propose a novel approach to alleviate these issues by replacing indirect volume preservation using Poisson's ratios with direct enforcement of zonal volume constraints, while controlling fine-scale volumetric deformation through a cell-wise compression penalty. To increase realism, we propose an epidermis model to mimic the dramatically higher surface stiffness on real skinned bodies. We demonstrate that our method produces stable realistic deformations with precise volume preservation but without locking artifacts. Due to the volume preservation not being tied to mesh discretization, our method also allows a resolution consistent simulation of incompressible materials. Our method improves the stability of the standard neo-Hookean model and the general compression recovery in the Stable neo-Hookean model.
翻译:在很多领域,包括视觉效应和服装设计,人体软组织与其环境接触的模拟至关重要。生物组织几乎无法压缩。但是,标准方法采用压缩弹性模型,通过将Poisson的比例定在接近0.5的情况下间接实现不压缩。这种方法可以产生质量上合理但不准确的定量结果。这种方法还造成数字不稳定,锁定粗离散性,或者对时间步骤的大小造成令人望而却步的限制。我们建议采用新颖的方法,通过直接强制实施区域体积限制,用Poisson的比例取代间接体积保护,同时通过控制小体积的微量变形,同时通过细胞的压缩罚款来控制微量变形。为了增加现实主义,我们提出了一种外观模型,以模拟实际皮肤身体表面高度高的僵硬度。我们证明我们的方法产生稳定的、现实的变形,精确的体积保存,但不锁定工艺品。由于体积的保持与离散性相比,我们的方法也允许一种分辨率的模型,对抑制性体积进行模拟。我们的方法改进了全面压缩材料的模型的稳定性。我们的方法改进了新的方法。