In this work we analyze and address a fundamental restriction that blocks the reliable application of codimensional yarn-level and shell models with thickness, to simulate real-world woven and knit fabrics. As discretizations refine toward practical and accurate physical modeling, such models can generate non-physical contact forces with stencil-neighboring elements in the simulation mesh, leading to severe locking artifacts. While not well-documented in the literature, this restriction has so far been addressed with two alternatives with undesirable tradeoffs. One option is to restrict the mesh to coarse resolutions, however, this eliminates the possibility of accurate (and consistent) resolution simulations across real-world material variations. A second alternative instead seeks to cull contact pairs that can create such locking forces in the first place. This relaxes resolution restrictions but compromise robustness. Culling can and will generate unacceptable and unpredictable geometric intersections and tunneling that destroys weaving and knitting structures and cause unrecoverable pull-throughs. We address these challenges to simulating real-world materials with a new and practical contact-processing model for thickened codimensional simulation, that removes resolution restrictions, while guaranteeing contact-locking-free, non-intersecting simulations. We demonstrate the application of our model across a wide range of previously unavailable simulation scenarios, with real-world material yarn and fabric parameters and patterns, challenging simulation conditions and mesh resolutions, and both rod and shell models, integrated with the IPC barrier.

翻译：本文分析并解决了一个基本限制，该限制阻碍了带厚度的共维纱线级和壳模型在模拟真实世界机织与针织织物时的可靠应用。随着离散化向实用且精确的物理建模方向细化，此类模型可能在模拟网格中与模板相邻单元产生非物理接触力，导致严重的锁定伪影。尽管文献中对此记录不详，但迄今为止，该限制通过两种具有不良权衡的替代方案得以应对。一种选择是限制网格至粗分辨率，但这消除了在真实世界材料变化范围内进行精确（且一致）分辨率模拟的可能性。第二种替代方案则试图首先剔除可能产生此类锁定力的接触对。这放宽了分辨率限制，但牺牲了鲁棒性。剔除可能且必将产生不可接受且不可预测的几何相交与穿透，从而破坏编织与针织结构，并导致不可恢复的拉穿现象。我们通过一种新颖且实用的增厚共维模拟接触处理模型来应对这些模拟真实世界材料的挑战，该模型消除了分辨率限制，同时保证了无接触锁定、无相交的模拟。我们展示了该模型在广泛先前无法实现的模拟场景中的应用，包括真实世界材料的纱线与织物参数及图案、具有挑战性的模拟条件和网格分辨率，以及与IPC屏障集成的杆模型和壳模型。