Start a particle’s animation when it’s in a certain location with animation nodes?

Question

That title is quite the mouthful, so I’ll try to explain my issue as best I can, which I had for like 5 days now and simply can’t find any solution to.

Context:

I have a plain that is subdivided a bunch of times, and is being warped from point A to B (not really important where, just from one place to another) with a warp modifier. I have a hair type particle applied to this plane, and the particle itself is an instanced object that is rigged with an armature, and is animated from frame 1-80 on the timeline.

Issue:

The problem is that on the plane, all the particles animate at the exact same time from frame 1-80, which is not what I want.

Desired result:

What I actually want to happen is that the particles should animate when they’ve been warped to point B. This of course means that when it’s warped, the particle is in a different xyz coordinate, which I’ve read can be used to trigger the animation of the particle using animation nodes. (specifically I’ve read it here, which I’m not exactly sure is still useful info considering that thread is over 8 years old) So for example’s sake, let’s say when the Y coordinate of the particle is 0<= then start the animation.

Now I’m completely new to animation nodes, I just installed the addon, and watched some pretty basic tutorials on it. So I have absolutely no idea how to accomplish this task. I'm not sure AN is even needed to achieve what I want, but from the dozens of threads I've gone through, it seem it's my only option. So if you can help with this, or perhaps have any other idea on how to achieve this result with other methods, I’d be very grateful for any help!

Thanks!

Answer 1

Not sure if this will be helpful, but I had a similar project where I was trying to animate a crowd of simple stick figures, but wanted them to be in different parts of their walk cycle so they didn't look like they were marching.

In my case, rather than rigging, I used shapekeys to animate the characters, used particles to instance the objects (as you're doing,) then had animation nodes cycle through the shapekey animation based on the overall animation frame #, but assign a unique offset value for each character's animation so they wouldn't be in lockstep.

Using shapekeys like this worked for my simple animation, not sure if it would work for your situation. Sample attached.