How to project points onto a curve vertically down?

Hi there, I have one curve directly above the other (in the z-axis) and would like for the points of the top curve to be projected vertically downwards onto the second curve so that I have several points which allow me to create vertical lines. This is not the nearest point I’m looking for, just a vertical line from top to bottom.
rollercoasterfirstgo (1).gh (18.2 KB)

Hi -

It wasn’t clear which curves you refer to in that file but just using a Line SDL with the Unit Z vector as the direction from the points on the upper curve should give you the intersection with the bottom curve using the Curve | Line intersection component.

wonderful thank you!