CAREER: Constraint-based Adaptive Simulation of Deformable Objects

本研究的目标是开发强大而有效的技术来建模、模拟和与软物体交互。可变形物体的物理建模是许多图形和科学可视化应用的基础和关键组成部分之一，它提供了一种有效的方式来显示和交互虚拟物体，更好地代表真实的物理性质，超越了不切实际的刚体近似。软物体建模已经广泛地研究了离散模型和基于连续介质力学的模型。然而，两个主要问题仍然构成重大挑战。首先，计算效率和生物力学现实主义之间的冲突要求我们做出权衡，或者牺牲一个来换取另一个。其次，软物体和直观控制之间的交互作用的稳健处理经常被忽视，由单个接触点或给定的外力表示。PI将解决以下几个方面的问题：1)表示复杂对象结构的域分解方法；2)在保持整体动态行为的同时，对模型进行自适应细化和简化；3)基于鲁棒约束的可变形物体碰撞与接触分析；4)约束操作，用户界面直观灵活；5)快速集群计算环境及相关并行算法。这个项目的教育部分包括：1)开发一个新的基于物理的建模和仿真课程；2)为一个虚拟手术系统开发一个真实的组织变形模型，该系统将用于培训医学生和外科医生；3)为K-12学生和公众开发功能解剖学在线可视化系统。4)举办“事物是如何工作的”研讨会和动画比赛，为本科生和研究生的早期学术生涯提供研究经验。

The goal of this research is to develop robust and effective techniques to model, simulate and interact with soft objects. The physical modeling of deformable objects is one of the fundamental and crucial components of many graphics and scientific visualization application providing an effective way to display and interact with virtual objects that better represent true physical nature, beyond unrealistic rigid-body approximation. Soft object modeling has been studied extensively using both discrete models and continuum mechanics-based models. However, two major issues still pose a significant challenge. First, the conflicting demand between computational efficiency and biomechanical realism directs us to take trade-offs or to sacrifice one for the other. Second, the robust treatment of interaction between soft objects and intuitive control is often overlooked, being represented by a single point of contact or given external forces. The PI will address issues in the following areas: 1) domain decomposition method to represent a complex object structure; 2) adaptive refinement and simplification of the model while preserving overall dynamic behavior; 3) robust constraint-based collision and contact analysis between deformable objects; 4) constrained manipulation for intuitive and flexible user interface; and 5) fast cluster computing environment and associated parallel algorithms. The educational component of this project includes 1) development of a new physically-based modeling and simulation curriculum, 2) development of a realistic tissue deformation model for a virtual surgery system which will be used for training medical students and surgeons, 3) development of functional anatomy online visualization system for K-12 students and the general public, and 4) hosting "How Things Work" workshop and animation contest to foster research experiences for undergraduate and graduate students in their early academic careers.