Direct Position‐Based Solver for Stiff Rods

dc.contributor.authorDeul, Crispinen_US
dc.contributor.authorKugelstadt, Tassiloen_US
dc.contributor.authorWeiler, Marcelen_US
dc.contributor.authorBender, Janen_US
dc.contributor.editorChen, Min and Benes, Bedrichen_US
dc.date.accessioned2018-08-29T06:56:06Z
dc.date.available2018-08-29T06:56:06Z
dc.date.issued2018
dc.description.abstractIn this paper, we present a novel direct solver for the efficient simulation of stiff, inextensible elastic rods within the position‐based dynamics (PBD) framework. It is based on the XPBD algorithm, which extends PBD to simulate elastic objects with physically meaningful material parameters. XPBD approximates an implicit Euler integration and solves the system of non‐linear equations using a non‐linear Gauss–Seidel solver. However, this solver requires many iterations to converge for complex models and if convergence is not reached, the material becomes too soft. In contrast, we use Newton iterations in combination with our direct solver to solve the non‐linear equations which significantly improves convergence by solving all constraints of an acyclic structure (tree), simultaneously. Our solver only requires a few Newton iterations to achieve high stiffness and inextensibility. We model inextensible rods and trees using rigid segments connected by constraints. Bending and twisting constraints are derived from the well‐established Cosserat model. The high performance of our solver is demonstrated in highly realistic simulations of rods consisting of multiple 10 000 segments. In summary, our method allows the efficient simulation of stiff rods in the PBD framework with a speedup of two orders of magnitude compared to the original XPBD approach.We present a novel direct solver for the efficient simulation of stiff, inextensible elastic rods. It is based on the XPBD algorithm, which extends Position‐Based Dynamics to simulate elastic objects with physically meaningful material parameters. However, the non‐linear Gauss‐Seidel solver of XPBD requires many iterations to converge for complex models and if convergence is not reached, the material becomes too soft. In contrast, we use Newton iterations in combination with our direct solver which significantly improves convergence by solving all constraints of an acyclic structure simultaneously. We model rods using rigid segments connected by constraints. Bending and twisting constraints are derived from the Cosserat model. The high performance of our solver allows the simulation of rods consisting of multiple 10 000 segments with a speedup of two orders of magnitude compared to the original XPBD approach.en_US
dc.description.number6
dc.description.sectionheadersArticles
dc.description.seriesinformationComputer Graphics Forum
dc.description.volume37
dc.identifier.doi10.1111/cgf.13326
dc.identifier.issn1467-8659
dc.identifier.pages313-324
dc.identifier.urihttps://doi.org/10.1111/cgf.13326
dc.identifier.urihttps://diglib.eg.org:443/handle/10.1111/cgf13326
dc.publisher© 2018 The Eurographics Association and John Wiley & Sons Ltd.en_US
dc.subjectphysically based animation
dc.subjectanimation
dc.subjectComputing methodologies → Physical simulation
dc.titleDirect Position‐Based Solver for Stiff Rodsen_US
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