Accurate and Efficient Visual Simulation of Fiber-based Mechanical Structures

基于纤维的机械结构的准确和高效的可视化模拟康奈尔大学的Steve Marschner在计算机图形模拟中的许多最困难的挑战涉及到由纤维组成的材料。在外观很重要的应用中，从设计纺织品和服装到渲染虚拟演员再到配制头发化妆品，了解这些材料的物理属性如何影响它们的运动和外观是至关重要的。基于纤维的结构的行为与其他材料不同。针织面料比其成分纱线具有更大的延伸性，因为纱线可以弯曲和滑动成不同的宏观形状。一头长发自由而平稳地移动，建立和打破数以百万计的头发-头发接触，产生一个部分平滑，部分不连续的整体运动。这项研究旨在通过从根本上改变底层的物理和计算模型来提高布料和头发模拟的准确性。该项目遵循测量、建模、模拟和验证的方法。基于图像的测量用于捕捉织物的完整变形。这些数据与纱线水平纺织力学的文献一起被用来开发基于织物实际物理的本构模型，该模型使用纺织品模拟中通常不使用的高级数值方法来模拟。结果正在根据实验室数据和服装设计中的实际问题进行评估。通过将现代图形和模拟工具与纺织力学详细模型在严格的验证过程中结合在一起，该项目为未来的计算机图形布料模拟奠定了坚实的科学基础。为纤维-纤维相互作用设计的计算方法也正在扩展，以实现对头发的高效线级模拟。在模拟得到验证后，该项目将检查近似值和算法，以实现有效的模拟。最终的结果将是新的、基于物理的布料和头发力学模型，适合于视觉应用。

Accurate and Efficient Visual Simulation of Fiber-based Mechanical StructuresSteve Marschner, Cornell UniversityMany of the most difficult challenges in simulation for computer graphics involve materials composed of fibers. In applications where appearance matters, from designing textiles and apparel to rendering virtual actors to formulating hair cosmetics, understanding how these materials' physical properties affect their motion and appearance is crucial. Fiber-based structures behave differently from other materials. A knit fabric is much more extensible than its component yarns because the yarns can bend and slide into different macroscopic shapes. A head of long hair moves freely but smoothly, making and breaking millions of hair-hair contacts to produce a partly smooth, partly discontinuous overall motion. This research aims to improve the accuracy of cloth and hair simulation by fundamentally changing the underlying physical and computational models.The project follows an approach of measurement, modeling, simulation, and validation. Image-based measurement is used to capture complete fabric deformations. This data, together with the literature on yarn-level textile mechanics, is used to develop constitutive models based on the actual physics of fabric, which are simulated using advanced numerical methods not normally employed in textile simulation. The results are being evaluated both against the laboratory data and in the context of real problems in apparel design. By bringing together the tools of modern graphics and simulation with the detailed models of textile mechanics in a rigorous process of validation, this project is placing computer graphics cloth simulation on a firm scientific foundation for the future. Computational methods devised for fiber-fiber interactions are also being extended for efficient strand-level simulation of hair. After the simulations are validated, the project will examine approximations and algorithms to allow efficient simulation. The end result will be new, physics-based models for the mechanics of cloth and hair that are appropriate for visual applications.