Liquify — Rewind function
In case you overdid something.
The Rewind function lets you soften the deformation applied to the artwork with the Liquify tools.
It is however not the undo history; it reverses the deformations globally.
The grid completely smoothened (zero deformation)
An intermediate state (less deformation)
Current state of deformation (image deformed with any Liquify tools).
Note that in the Rewind mode the slider does not control the size of the tool. The slider adjusts the amount of smoothing of the grid.
The Rewind affects only the deformations applied in the current session of Liquify. After each session the grid is reset.