Walk In the Park
I definitely ran into some road blocks while figuring this out. The biggest problem was the lag. To fix I switched the execution from Automatic to Manual. My approach was based on attractor logic, where the height of every block in the grid is controlled by its distance to the attractor point. I used a sine wave formula in a Code Block to transform those distances into height values, creating a ripple effect across the plaza. They originally sank halfway into the ground fixed this by using Geometry.Translate node to shift everything up.
Eliminate the Echo
I started by making XY plane 12 feet up to make a ceiling and filled it with a grid of cylinders. Then, I made a point with X and Y sliders to act as the heart of my ripple effect. To get the wave working, I used a chain of math nodes to measure distances and turn them into smooth sine ripples that project downward. I finally hooked everything into a ScaleNU node and I hid the original flat cylinders. No problems with lag using grasshopper.