--recordFreeWater
Record output from tensor plus free water model: Save the fraction of
free water. Attaches field 'FreeWater' to fiber. (value: 0)
--freeWater
Adds a term for free water diffusion to the model. The free water
model is a tensor with all 3 eigenvalues equal to the diffusivity of
free water (0.003). To output the free water fraction, make sure to
use the 'save free water' parameter. (value: 0)
https://github.com/pnlbwh/ukftractography/blob/2c859b318ab3125c54750045a5e3877fcd50139d/ukf/cli.cc#L100-L103
save free water
to--recordFreeWater