In Houdini, I have a POP network that generates particle movement. I connect the particles to an Alembic object, a fish. I would like the Alembic object to deform along with the movement of the particles. Not just to follow the particle, but to deform along the curve drawn by the particle.

To make lines from particles in motion, you use the trail sop followed by an add. You need to have id attribute turned on inside the popnet.

Check out this post for a way to deform once you have a set of lines.
https://forums.odforce.net/topic/39351-kohuei-nakamas-effect/?tab=comments#comment-190689 [forums.odforce.net]

Thank you. This helps a lot. One thing I can't seem to do is this: I use this module to create a school of fish. The popnet is used to define the trajectory of each fish. I would like to be able to give the Path Deform random input geometries (here, different Alembic animations). It seems that I can't set input attributes in the Path Deform.

You can use the Piece Attribute on Path Deform SOP.

I resolved the problem by employing an `AttribAdjustInteger` node to split the particles. Subsequently, I utilized a series of `Delete` nodes, along with a 'filter expression', to segment the geometry for the `Path Deform`. There might be a more flexible approach available.