I have a simple particle system to simulate fallen leaves (With a simple leaf quad and texture sheed animation)
I have activated the “Collision” module to stop the leaves when they touch the ground.
I also set “Rotation over lifetime” to make the leaves rotate a bit.
The problem is: The leaves keep rotating once they touched the ground, which looks really silly (like breakdancers).
I did not found a fitting setting in the “Collision” module.
I was also trying to change the rotation from “Rotation over Lifetime” to “Rotation by Speed” but I did not find a setting that did work.
Whats the best way to stop the rotation once the leaves collide?
I don’t know of a way to do this - it was once on our roadmap to add an option for it, but unfortunately we only have enough resources to do bugfixing on that system now, as all feature work is focused on the Visual Effect Graph package instead.
after seeing the above response, i tried to create this effect on my own, since i ignored that you had tried rotation by speed already. it’s pretty simple, but it is VERY important that in the collision tab you use dampening or else it’ll rotate forever ~ though i’m assuming you do this already to stop them.
Sorry but this does not work and I am shocked and disappointed by that.
Rotation by Speed does what it sounds like but speed is a problematic term. This is speed before collision. A gravity modifier will continously set speed to a value above 0, the collision will prevent the particle from moving through the ground but the speed will remain greater than zero and therefore it will keep on rotation through Rotation By Speed.
In vfx graph you can fiddle around the issue by factoring the particle position height into the rotation value but in shuriken… this really sucks? How does anyone do these kind of effects there?
Edit:
Option A
Tweak rotation over life to be just good enough to be convincing and forget about rotation by speed.
Option B
Decrease the down force (gravity or force over lifetime) down to zero to a point during lifetime where all particles have collided with the floor and actually do use rotation over speed.
hi, in my post detailing it i mentioned using dampening in collision tab, i don’t recall having any issues with them continuing moving after collision once i added the dampening
not sure what your exact use case is, but for leaves specifically, my post detailed everything.
@POOKSHANK
thanks for the reply, in case my post came across that way, I didn’t mean to criticize your explanation / post but rather the unity particle system implementation. There was no intention to be rude. I very much appreciate you taking an interest and helping.
Okay I am setting up a particle system to explode a few rock pieces off the ground / a wall. High start speed, gravity modifier set to 1, Plane collision, dampening set to 1 to make it extra obvious. Rotation by speed set to curve, lower speed = 0 rotation.
Dampening does stop the particles from changing their position, yes, but if I use it with gravity it does not (apparently) reduce the speed value which is used to calculate rotation by speed as the pieces still rotate while lying on the ground.
