BEGIN:VCALENDAR
VERSION:2.0
PRODID:Linklings LLC
BEGIN:VTIMEZONE
TZID:Australia/Melbourne
X-LIC-LOCATION:Australia/Melbourne
BEGIN:DAYLIGHT
TZOFFSETFROM:+1000
TZOFFSETTO:+1100
TZNAME:AEDT
DTSTART:19721003T020000
RRULE:FREQ=YEARLY;BYMONTH=4;BYDAY=1SU
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:19721003T020000
TZOFFSETFROM:+1100
TZOFFSETTO:+1000
TZNAME:AEST
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20240214T070245Z
LOCATION:Meeting Room C4.9+C4.10\, Level 4 (Convention Centre)
DTSTART;TZID=Australia/Melbourne:20231214T090000
DTEND;TZID=Australia/Melbourne:20231214T091500
UID:siggraphasia_SIGGRAPH Asia 2023_sess165_papers_1020@linklings.com
SUMMARY:Capturing Animation-Ready Isotropic Materials Using Systematic Pok
 ing
DESCRIPTION:Technical Papers, TOG\n\nHuanyu Chen, Danyong Zhao, and Jernej
  Barbic (University of Southern California)\n\nCapturing material properti
 es of real-world elastic solids is both challenging and highly relevant to
  many applications in computer graphics, robotics and related fields. We g
 ive a non-intrusive, in-situ and inexpensive approach to measure the nonli
 near elastic energy density function of man-made materials and biological 
 tissues. We poke the elastic object with 3d-printed rigid cylinders of kno
 wn radii, and use a precision force meter to record the contact force as a
  function of the indentation depth, which we measure using a force meter s
 tand, or a novel unconstrained laser setup. We model the 3D elastic solid 
 using the Finite Element Method (FEM), and elastic energy using a compress
 ible Valanis-Landel material that generalizes Neo-Hookean materials by per
 mitting arbitrary tensile behavior under large deformations. We then use o
 ptimization to fit the nonlinear isotropic elastic energy so that the FEM 
 contact forces and indentations match their measured real-world counterpar
 ts. Because we use carefully designed cubic splines, our materials are acc
 urate in a large range of stretches and robust to inversions, and are ther
 efore "animation-ready" for computer graphics applications. We demonstrate
  how to exploit radial symmetry to convert the 3D elastostatic contact pro
 blem to the mathematically equivalent 2D problem, which vastly accelerates
  optimization. We also greatly improve the theory and robustness of stretc
 h-based elastic materials, by giving a simple and elegant formula to compu
 te the tangent stiffness matrix, with rigorous proofs and singularity hand
 ling. We also contribute the observation that volume compressibility can b
 e estimated by poking with rigid cylinders of different radii, which avoid
 s optical cameras and greatly simplifies experiments. We validate our meth
 od by performing full 3D simulations using the optimized materials and con
 firming that they match real-world forces, indentations and real deformed 
 3D shapes. We also validate it using a ``Shore 00'' durometer, a standard 
 device for measuring material hardness.\n\nRegistration Category: Full Acc
 ess
URL:https://asia.siggraph.org/2023/full-program?id=papers_1020&sess=sess16
 5
END:VEVENT
END:VCALENDAR