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DTSTAMP:20240214T070240Z
LOCATION:Darling Harbour Theatre\, Level 2 (Convention Centre)
DTSTART;TZID=Australia/Melbourne:20231212T093000
DTEND;TZID=Australia/Melbourne:20231212T124500
UID:siggraphasia_SIGGRAPH Asia 2023_sess209_papers_1020@linklings.com
SUMMARY:Capturing Animation-Ready Isotropic Materials Using Systematic Pok
 ing
DESCRIPTION:Technical Papers\n\nHuanyu Chen, Danyong Zhao, and Jernej Barb
 ic (University of Southern California)\n\nCapturing material properties of
  real-world elastic solids is both challenging and highly relevant to many
  applications in computer graphics, robotics and related fields. We give a
  non-intrusive, in-situ and inexpensive approach to measure the nonlinear 
 elastic energy density function of man-made materials and biological tissu
 es. We poke the elastic object with 3d-printed rigid cylinders of known ra
 dii, and use a precision force meter to record the contact force as a func
 tion of the indentation depth, which we measure using a force meter stand,
  or a novel unconstrained laser setup. We model the 3D elastic solid using
  the Finite Element Method (FEM), and elastic energy using a compressible 
 Valanis-Landel material that generalizes Neo-Hookean materials by permitti
 ng arbitrary tensile behavior under large deformations. We then use optimi
 zation to fit the nonlinear isotropic elastic energy so that the FEM conta
 ct forces and indentations match their measured real-world counterparts. B
 ecause we use carefully designed cubic splines, our materials are accurate
  in a large range of stretches and robust to inversions, and are therefore
  "animation-ready" for computer graphics applications. We demonstrate how 
 to exploit radial symmetry to convert the 3D elastostatic contact problem 
 to the mathematically equivalent 2D problem, which vastly accelerates opti
 mization. We also greatly improve the theory and robustness of stretch-bas
 ed elastic materials, by giving a simple and elegant formula to compute th
 e tangent stiffness matrix, with rigorous proofs and singularity handling.
  We also contribute the observation that volume compressibility can be est
 imated by poking with rigid cylinders of different radii, which avoids opt
 ical cameras and greatly simplifies experiments. We validate our method by
  performing full 3D simulations using the optimized materials and confirmi
 ng that they match real-world forces, indentations and real deformed 3D sh
 apes. We also validate it using a ``Shore 00'' durometer, a standard devic
 e for measuring material hardness.\n\nRegistration Category: Full Access, 
 Enhanced Access, Trade Exhibitor, Experience Hall Exhibitor
URL:https://asia.siggraph.org/2023/full-program?id=papers_1020&sess=sess20
 9
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