Play particle system backwards

Is it possible to make a particle system play backwards?

I found this: https://blender.stackexchange.com/questions/100279/how-to-reverse-particle-cache-in-blender-2-79#100296

… but …

I’m not having much luck creating a disk cache.

When I tick the “external” button I can no longer bake the particles!
I want to use the “explode” function to make an object that flies apart and then comes back together.

Could you export it as an Alembic?
You could then reimport it and animate the frame offset to move forward and backward through the frames.

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I believe external is for linking a cache folder.

Disk cache and use library path is used for baking the cache into a fodler aside of your project.

Perhaps baking it and then use that strip and reversing it could do it, im not sure though

I just found this article, its a but of a hack. Basically you bake the particle cache and then edit those files, basically reversing the order

I made a simple file and a preview, it acts wonky, It does seem to show most of them backwards. But some suddenly pop onto the sphere out from nowhere.

PS you need to delete the bake and bake again. then use your own system paths as described in the text editor. PS i renamed the file to _cleaned, so that cache folder name is different as i typed in the text editor.

Second, when you copy the files back, make sure you use move copy, other wise the next time you run the script it raises an error. The reversed (ouput) folder needs to be empty from the start


Reversed Particles_cleaned.blend (878.0 KB)

edit
When i use a short end time, i made sure the end is way before the end of the last frame in the scene, it does look better. Still goes a but wonky at the end.

Edit 2
I adjusted the script, you wont need to manually move them back, the script takes care of that now

Thankyou - that’s really helpful and I’ll give it a good look soon!