First, I started with creating a rectangular grid using the Coordinates function and the Cross-Product lacing.
Second, I created a coordinate for the pebble.
Then, I created the end points for the cylinders using the Distance function from the pebble to every point on the grid. These end points had a z value that was a sine-wave function.
Then, I used the Translate function to produce the set of end points for the Create Cylinders function.
Finally, all the parameters required in Revit were produced.