VCG - FTLE

Description

Performs FTLE on the data and returns a scalar field. Input may be of up to 4-Dimensions.

Details


The Finite-Time-Lyapunov-Exponent is an important scalar measure for estimating particle separation behavior, quantifying the rate of divergence in trajectory of two infinitesimally close particles in each point of the field over a finite integration time. Generally, the FTLE is understood as the logarithm of the largest absolute eigenvalue of the gradient at a given (seed) point, divided through the integration time.
The approach by this plugin uses simple central differences to calculate the gradient for each seed point.

Input

vtkImageData

Output

vtkImageData

Parameters

Name
Description
 Values/Default
SeedBoxSamples Number of seed points in each dimension. 10 10 10
SeedPosition Origin of the box in which particles are seeded. 0.0 0.0 0.0
SeedScale Scale of the box in which particles are seeded. 1.0 1.0 1.0
StartTime Initial time of trajectory integration. 0.0
AdvectionTime Integration is computed from StartTime to StartTime + AdvectionTime with steps StepSize. Set AdvectionTime and StepSize to negative values for backward integration. 1.0
StepSize Step size of integration. 0.1
Use CUDA Enable CUDA GPU-Acceleration. 0
BlockSize Block size of CUDA computation. 1000000
SpaceTimeInput Treat the third dimension as time. Only has an effect, if the input is 3-dimensional and not time-dependent. 0
BoundaryMode0 Set Boundary Mode for the first dimension. None will lead to trajectories leaving the scope, Wrap makes trajectories wrap around and Clamp will restrict particle trajectories.
  • None
  • Wrap
  • Clamp
BoundaryMode1 Set Boundary Mode for the second dimension. See desc. of first dimension.
  • None
  • Wrap
  • Clamp
BoundaryMode2 Set Boundary Mode for the second dimension. See desc. of first dimension.
  • None
  • Wrap
  • Clamp
BoundaryMode3 Set Boundary Mode for the second dimension. See desc. of first dimension.
  • None
  • Wrap
  • Clamp

Installation Instructions

Authors

Lutz Hofmann

Acknowledgements