Format
filter(type=“ripple”, …)
Args
x: Horiztonal position of ripple center, relative to image center (defaults to 0)
Applies a ripple distortion effect to this image.
This filter is meant to be animated. A good animation will typically start at a radius of 0 and animate to a larger value, with size decreasing to 0.
The falloff parameter can be tweaked to your liking. A value of 1 should look reasonably like ripples in water, with the inner ripples losing strength. A value of 0 will cause no reduction in strength.
The equation governing the ripple distortion is size × sin(2πr’) ÷ (2.5 × falloff × r’2 + 1), where r’ = (radius - distance) ÷ repeat.
Up to 10 ripples can be stacked together in a single pass of the filter, as long as they have the same repeat, falloff, and flags values. (See the wave filter for the WAVE_BOUNDED flag.)