README.md

IPC Legacy Script Setting Commands

• warmStart {0-5}: with intersection-free constraints, warmstart barely accelerate the optimization
  • 0: initial position (no warm start, default) (xⁿ)
  • 1: initial position + integrated velocity (xⁿ + Δt vⁿ)
  • 2: initial position + integrated velocity + doubly integrated gravity (xⁿ + Δt vⁿ + Δt² g)
  • 3: uniformly accelerated warm start
  • 4: symplectic Euler warm start
  • 5: Jacobi warm start
• CCDMethod {FloatingPointRootFinder | RootParity | BSC | RationalRootParity | TightInclusion | ...}: By default, IPC uses a floating-point version of CCD together with edge-triangle intersection checks as safeguard, which is much faster than exact CCD and does not have any failure cases so far in practice
  • which method of exact CCD to use (default: FloatingPointRootFinder)
  • FloatingPointRootFinder: use the floating-point root finder method implemented by Etienne Vouga
  • TightInclusion: use our new provably conservative CCD [Wang et al. 2021]
  • RootParity: use the root parity method of Brochu et al. [2012], which in fact has failure cases in our experiments (e.g. sphere roller)!
  • BSC: use the Bernstein sign classification method of Tang et al. [2014], which in fact has failure cases in our experiments (e.g. sphere roller)!
  • RationalRootParity: use our reimplementation with rational numbers of the root parity method in Brochu et al. [2012], which in fact does not handle double collisions in a single time-step (a limitation of the original [Brochu et al. 2012])!
  • For more options see https://github.com/Continuous-Collision-Detection/CCD-Wrapper
• tuning <positive-integer>: please use dHat, epsv, fricIterAmt, and tol to control accuracies instead
  • number of accuracy parameters to be set followed by that number of realNumber
• meshCO <mesh-file-path> <x> <y> <z> <scale> <stiffness> <friction-coefficient>
  • a legacy way of specifying static collision object, which lacks many important features, so please use shapes with linearVelocity or angularVelocity extra keyword instead
• shape input <script-file-path>
  • a legacy way of specifying a single input shape, where assigning materials, bounary conditions, or initial velocities are not supported, so please use shapes instead
• shapeMatrix input <num-x> <num-y> <num-z>
  • a legacy way of specifying a matrix of a shape with <num-x>, <num-y>, and <num-z> number of that shape in each axis, followed by a line in the format of:
  • <mesh-file-path> <dx> <dy> <dz> <rot-deg-x> <rot-deg-y> <rot-deg-z> <scale-x> <scale-y> where <dx>, <dy>, and <dz> sets the distance between adjacent objects in each axis.
  • assigning materials, boundary conditions, or initial velocities are not supported in this command, so please use shapes instead
• rotateModel <rot-axis-x> <rot-axis-y> <rot-axis-z> <rot-deg>
  • rotate all models as a single one in model space with rotDeg degrees along direction [rot-axis-x rot-axis-y rot-axis-z]
  • please orient shapes using shapes instead
• size <size>
  • size of the bounding box in meters for IPC to rescale the scene
  • -1 (default): do not rescale, which adds less complication to scene settings
• script {null | scaleF | hang | hang2 | swing | stamp | undstamp | stand | slip | topbottomfix | corner | push | tear | upndown | stretch | squash | stretchnsquash | bend | twist | twistnstretch | twistnsns | twistnsns_old | rubberBandPull | fourLegPull | headTailPull | onepoint | random | fall | dragdown | dragright | toggleTop | ...}
  • Different animation scripts (see src/AnimScripter.cpp for details)
  • By default it is set to null, where all settings can be set via script in a general way (see our quick start guide)
• handleRatio <ratio>
  • a legacy way of specifying the proportion of fixed vertices for setting Dirichlet boundary conditions
  • ratio must be greater than zero and less than one
  • please use shapes command with DBC extra keyword instead