First, I’ll state that there probably is an easier and better way to get this effect.
I create a plane, subdivide a few times and deleted all but a single row of verts and edge. There are no faces.
I deleted all the edges (x only edges) I have now 17 verts floating in space in a line.
I added a particle system, 0 gravity, 0 normal, it lasts from frame 1 to frame 50 lifetime 1000
Particle systemj is set to emit from verts, not random
particle system emits from a group of (2) objects a pink bonbon (Eww) and a chocolate bon bon (yum) size in my case .2, random size .3
Now by default the emission fills in these particles in particlar order based on the verts internal index. So I went into front view and swapped a few of the verts order. the first become shte 7th, and the 7th the 1st, changed 3-4.
Next to give random y spacing, I selected a single vert, turned on proptional edit (enabled, not connected) set it to random. Hit G Y and used my scrollwheel to make the radius larger than all the verts, and moved it on y axis a little bit.
I baked the system.
I duplicated the object (the row of verts) moved it up on z axis, in the particle system, where it says ‘particle settings’ I hit the 2 next it to make it single user. Otherwsie changes made to it will affect the first particle system. Free bake.
I changed the start time to 50, end time to 100. I changed the x order of some of the verts to avoid repitition, and did the proportional edit on the y axis.
…duplicate, move up, hit 2, free bake, change start and end times, move verts, bake …
It’s a pain the *** I hope somebody can give a better method, I really do.
Here’s a blend