Ehi everybody, first question here. Sorry if I’m writing this in the wrong section, I hope general questions about POPs are allowed.
I’m experimenting with POPs and trails and I would like the trails generation to be reversed.
In other words, I would like that, according to some parameter I have, the particles step back along the trail and come back to the origin.
Basically, image playing the animation backward.
Do you have any suggestion, please?
Thank you very much in advance.
Best
Hello,
So I think this would have to be a two steps process, where first you create the trails, and then you animate them shrinking.
See attached toe for a starting point, hopefully that’s what you meant!
A couple of notes: locked POPs currently are not saved when the toe is saved, so for simplicity I’m going through SOPs and locking the SOP with the trails that have been generated in POPs.
(just noticing it also looks like there’s currently a bug in POP to SOP which creates too many points, will look into that)
Another way would be to save them to file, again there’s currently no easy way to save POPs geometry, though that’s on our list, so the easiest would be to go through SOPs.
Then I’m creating an attribute that goes from 0 to 1 for each trail using line metrics POP and using that to progressively shrink them with a delete POP, by attribute.
You could tweak attributes a bit to animate the trail shrinking at different times or different speeds.
You can also post process the trails with a line divide to resample them if needed.
We might add a Carve POP in the future to simplify this, similar to the carve SOP (though I don’t think the carve SOP would allow you to animate each trail shrinking differently)
BackwardTrails.toe (469.1 KB)
Best,
Vincent
ps: the cache POP could be another way to freeze the trails, though again that wouldn’t get saved to disk
Sorry for my late response.
Thank you heaps! I admit I haven’t fully understood the .toe, but I’ve found that using the linemetrics and delete POPs was enough for my use case.
Best,
Nicola
Glad this was helpful! And keeping this in mind for further improvements in POPs