Two circles sharing the same Y value while one circle follows a spline?

I asked a similar question a couple days ago about only using the y variable of a circle. The thing is, I want the red circle to follow a spline as well, and it seems that I can’t do both at the same time. Is there any way at all for the blue circle to share the same y coordinate as the red circle WHILE the red circle follows a spline? The red circle can be a different object, its only purpose is to tell the blue circle what its y coordinate should be

Animation Synfig 3

Easy stuff. Export spline you want to use as path, connect red circle to it, convert blue circle’s origin to “Composite”. Leave X-Axis as it is, Y-Axis convert to “Vector Y”, then to “Spline Vertex”. Connect its “Spline” parameter to previously exported path. Export its “Amount” parameter. Connect exported “Amount” in red circle.

Make sure that “Loop” and “Homogeneous” parameters of the “Spline Vertex” converters of both red and blue circles are the same.

Here’s what I got:

Here’s the source file:
SeparateY.sif (13.3 KB)


Seems like I can always count on you to know this stuff! Thanks a lot once again :raised_hands: