Results

The project led to a diverse set of results, implying multidisciplinary collaborations:

	A new methodology for validating quantitatively simulators of slender elastic structures and frictional contact. Our work includes validation of theory against experiments, the setting up of new scaling laws for validation, and a thorough benchmarking of popular simulators from graphics and mechanical engineering, against a suite of four selected validation protocols. Related publications & communications: Romero et al. 2021, Physical validation of simulators in Computer Graphics: A new framework dedicated to slender elastic structures and frictional contact, ACM Transactions on Graphics 2021 (Proc. of ACM Siggraph 2021). Bertails-Descoubes 2021, “Physical validation of simulators made for Hollywood”, keynote presentation at the mini-workshop Rencontres du Non-Linéaires 2021. Bertails-Descoubes 2021, “La physique dans les jeux vidéos“, invited presentation (with David Louapre) at Colloque Sciences & Games 2021.
	A new non-invasive protocol for estimating material properties of cloth and friction during dynamic interaction, including cloth-solid and cloth-cloth interaction. The method relies on a neural network fed only with simulated data, after a careful validation of the simulator. Related publications & communications: Rasheed 2021, Inverse Dynamic Modeling of Cloth – Deep Learning using Physics based Simulations, PhD Thesis from Université Grenoble Alpes. Rasheed et al. 2021, A Visual Approach to Measure Cloth-Body and Cloth-Cloth Friction, IEEE PAMI 2021. Rasheed et al. 2020, Learning to Measure the Static Friction Coefficient in Cloth Contact, IEEE CVPR 2020. Rasheed et al. 2019, Estimating friction in cloth, using simulation and machine learning, APS March Meeting 2019.
	Two new accurate and fast frictional contact solvers for cloth: Argus, relying on a nodal and adaptive version of an implicit velocity-based formulation of the discrete nonsmooth frictional contact problem. Projective Friction, based on a light adaptation of the Projective Dynamics algorithm. Related publications & communications: Ly et al. 2020, Projective Dynamics with Dry Frictional Contact, ACM Transactions on Graphics 2020 (Proc. of ACM Siggraph 2020). Li et al. 2018, An Implicit Frictional Contact Solver for Adaptive Cloth Simulation, ACM Transactions on Graphics 2018 (Proc. of ACM Siggraph 2018).
	A new reduced discrete ribbon model, inspired from the super-clothoid model for thin elastic rods: elements are parameterized by a linear curvature and quadratic torsion. Developability of the mid-surface is accounted for by a constraint. The model has been validated against alternative (finite-differences) ribbon models and experiments. Related publications & communications: Charrondière 2021, Modélisation numérique de rubans par éléments en courbures, PhD thesis from Université Grenoble Alpes. Charrondière et al. 2020, Numerical modeling of inextensible elastic ribbons with curvature-based elements, CMAME 2020. Charrondière et al. 2019, Modélisation numérique de rubans en éléments de haut degré, Journées AFIG 2019 (best paper award). Charrondière et al. 2019, Modélisation numérique de rubans en éléments de haut degré, CSMA 2019.
	A new optimization procedure for recovering the natural shape of cloth deformed by gravity and frictional contact. Related publications & communications: Ly 2021, Static inverse modelling of cloth, PhD thesis from Université Grenoble Alpes. Ly et al. 2018, Inverse Elastic Shell Design with Contact and Friction, ACM Transactions on Graphics 2018 (Proc. of ACM Siggraph Asia 2018).
	A theorem of existence and uniqueness for the natural shape of a rod sagged under gravity. Related publications & communications: Bertails-Descoubes et al. 2018, Inverse design of an isotropic suspended Kirchhoff rod: theoretical and numerical results on the uniqueness of the natural shape, Proc. of the Royal Society A 2018. Romero et al. 2019, Inverse design of a suspended Kirchhoff rod: From theory to practice, APS March Meeting 2019.
,	The creation of the first graphics-physics workshop: Graphyz.