global parameters

disable-contact

Parameter

disable-contact

Default Value

False

Description

Disable Contact

Details

When enabled, the simulation will not perform any contact detection.

keep-states

Parameter

keep-states

Default Value

10

Description

Keep States

Details

Number of simulation states to keep in the output directory.

keep-verts

Parameter

keep-verts

Default Value

0

Description

Keep Vertices

Details

Number of vertex data files to keep in the output directory. 0 means no limit (unlimited). Minimum is 1 to ensure visualization.

dt

Parameter

dt

Default Value

0.001

Description

Step Size

Details

Step size for the simulation. Small step size increases accuracy, large step size increases speed but may cause solver divergence.

fitting

Parameter

fitting

Default Value

False

Description

Fitting Mode

Details

Enable fitting mode for the simulation. Adjusts step size and disables inertia.

playback

Parameter

playback

Default Value

1.0

Description

Playback Speed

Details

Playback speed. 1.0 is normal, >1.0 is faster, <1.0 is slower.

min-newton-steps

Parameter

min-newton-steps

Default Value

0

Description

Lower Bound of Newton Steps

Details

Minimal Newton’s steps to advance a step. Recommended 32 if static friction is present.

target-toi

Parameter

target-toi

Default Value

0.25

Description

Target Accumulated Time of Impact (TOI)

Details

Accumulated TOI threshold for Newton’s loop termination.

air-friction

Parameter

air-friction

Default Value

0.2

Description

Air Tangental Friction

Details

Ratio of tangential friction to normal friction for air drag/lift.

line-search-max-t

Parameter

line-search-max-t

Default Value

1.25

Description

Extended Line Search Maximum Time

Details

Factor to extend TOI for CCD to avoid possible solver divergence.

constraint-ghat

Parameter

constraint-ghat

Default Value

0.001

Description

Gap Distance for Boundary Conditions

Details

Gap distance to activate boundary condition barriers.

constraint-tol

Parameter

constraint-tol

Default Value

0.01

Description

Moving Constraint Minimum Gap Tolerance

Details

This factor is multiplied to the constraint gap to determine the CCD tolerance for moving constraints.

fps

Parameter

fps

Default Value

60.0

Description

Frame Per Second for Video Frames

Details

Frame rate for output video.

cg-max-iter

Parameter

cg-max-iter

Default Value

10000

Description

Maximum Number of PCG Iterations

Details

PCG solver is regarded as diverged if this is exceeded.

cg-tol

Parameter

cg-tol

Default Value

0.001

Description

Relative Tolerance for PCG

Details

Relative tolerance for PCG solver termination.

ccd-eps

Parameter

ccd-eps

Default Value

1e-07

Description

ACCD Epsilon

Details

Small thickness tolerance for ACCD gap distance checks.

ccd-reduction

Parameter

ccd-reduction

Default Value

0.01

Description

CCD Reduction Factor

Details

This factor is multiplied to the initial gap to set the CCD threshold.

ccd-max-iter

Parameter

ccd-max-iter

Default Value

4096

Description

Maximum CCD Iterations

Details

The maximum number of iterations for ACCD.

max-dx

Parameter

max-dx

Default Value

1.0

Description

Maximum Search Direction

Details

Maximum allowable search direction magnitude during optimization.

eiganalysis-eps

Parameter

eiganalysis-eps

Default Value

0.01

Description

Epsilon for Eigenvalue Analysis

Details

Epsilon for stable eigenvalue analysis when singular values are close.

friction-eps

Parameter

friction-eps

Default Value

1e-05

Description

Epsilon for Friction

Details

Small value to avoid division by zero in quadratic friction model.

csrmat-max-nnz

Parameter

csrmat-max-nnz

Default Value

10000000

Description

Maximal Matrix Entries for Contact Matrix Entries on the GPU

Details

Pre-allocated contact matrix entries for GPU. Too large may cause OOM, too small may cause failure.

bvh-alloc-factor

Parameter

bvh-alloc-factor

Default Value

2

Description

Extra Memory Allocation Factor for BVH on the GPU

Details

Factor to pre-allocate BVH memory on GPU.

frames

Parameter

frames

Default Value

300

Description

Maximal Frame Count to Simulate

Details

Maximal number of frames to simulate.

auto-save

Parameter

auto-save

Default Value

0

Description

Auto Save Interval

Details

Interval (in frames) for auto-saving simulation state. 0 disables auto-save.

barrier

Parameter

barrier

Default Value

cubic

Description

Barrier Model for Contact

Details

Contact barrier potential model. Choices: cubic, quad, log.

stitch-stiffness

Parameter

stitch-stiffness

Default Value

1.0

Description

Stiffness Factor for Stitches

Details

Stiffness factor for the stitches.

air-density

Parameter

air-density

Default Value

0.001

Description

Air Density

Details

Air density for drag and lift force computation.

isotropic-air-friction

Parameter

isotropic-air-friction

Default Value

0.0

Description

Air Dragging Coefficient

Details

Per-vertex air dragging coefficient.

gravity

Parameter

gravity

Default Value

-9.8

Description

Gravity Coefficient

Details

Gravity coefficient.

wind

Parameter

wind

Default Value

0.0

Description

Wind Coefficient

Details

Wind strength.

wind-dim

Parameter

wind-dim

Default Value

0

Description

Wind Direction

Details

Wind direction.

include-face-mass

Parameter

include-face-mass

Default Value

False

Description

Flag to Include Shell Mass for Volume Solids

Details

Include shell mass for surface elements of volume solids.

fix-xz

Parameter

fix-xz

Default Value

0.0

Description

Whether to fix xz positions

Details

Fix xz positions for falling objects if y > this value. 0.0 disables. Use an extremely small value if nearly a zero is needed.

fake-crash-frame

Parameter

fake-crash-frame

Default Value

-1

Description

Fake Crash Frame

Details

Frame number to intentionally crash simulation for testing. -1 disables.