You can find this filter through
→ → .It displaces the pixels of the active layer or selection to waves or ripples reminding a reflection on disturbed water.
The result of your settings will appear in the Preview without affecting the image until you click on
.Antialiasing: This improves the scaled look the image borders may have.
Retain Tileability: This preserves the seamless properties if your image is a tile pattern.
That's the Horizontal or Vertical direction of waves.
Because ripples cause pixel displacement, some pixels may be missing on the image sides:
With Wrap, pixels going out one side will come back on the other side, replacing so the missing pixels.
With Smear, the adjacent pixels will spread out to replace the mixing pixels.
With Black, the missing pixels will be replaced by black pixels.
These options are self-explanatory
Sawtooth
Sine
The Period is related to wavelength (0-200 pixels)
The Amplitude is related to wave height (0-200 pixels).