Speed of particle in Path Sampler

Question

I use Path sample- to make circle of riding particle

But i cant understand- how change speed of this particle effect!

Here a link to video of my progress

https://youtu.be/386JbbNchtE

Comments

if i use
float st=spawner.LifeRatio;
Position = 1*Path_1.samplePosition(st);
I have- 1xSpeed
Position = 1*Path_1.samplePosition(wavesaw(3*st));    
or
Position = 1*Path_1.samplePosition(frac(3*st));
i have 3x speed
but i cant understand -how do -for example- 0.5 of speed?

Answer 1

Hi,

You are using the spawner's liferatio, which is the liferatio of the emitter (layer), not the particle.

You could try:

Position = Path_1.samplePosition(LifeRatio);, but not in the spawner script, in an evolver script.

This will move your particles during their lifetime along the path. From that you can start experimenting and just do:

Position = Path_1.samplePosition(LifeRatio * 0.5); and it'll work correctly.

Cheers

Comments

the main problem is that Life ratio is (0..1)
And when you have Position = Path_1.samplePosition(LifeRatio * 0.5);
You will have only half of path- because in 1 it will be only 0.5!
When you have Position = Path_1.samplePosition(LifeRatio * 3);
its not problem- its faster! i dont know why- you must have Life ratio max =3 in this case- but is can be (0..1)
Maybe- its mean that its max - 3 of path- and its like 1 (one point on the path)
but for >=1 Its work
if its <1 - not work! its only part of path!
Maybe- because its mean that all point of path is (0..0.5) in this case<1!

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That is because of the particle's Life is 1 second by default (you can change that in the spawner's script Life = 2; for example)

LifeRatio is the particle's normalize age, when the particle spawns, it has a LifeRatio of 0, when it dies it's 1, so no matter what you plug in Life, LifeRatio will always be [0-1]

You can try Position = Path_1.samplePosition(LifeRatio); and try tweaking the Life, it should modify how fast the particle moves along the path

You could also use, spawner.age, scene.time, Age which are other helpful properties

Cheers

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ok. Can you write common parameters for layer
 and script in evolver- to have 0.5 of speed of it? thanks
I will try it! and make video!
Because- because i try all variants- what you say- and have no result!
Thanks!

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Here is a quick example: https://youtu.be/oovY4HRbpI4

Does it help ?

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Yes- thanks! my mistake was that i use Loop particle System from start!

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Yes the loop button is tricky sometimes, I am flagging the question answered then

Cheers

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But if i need Loop - because i need non stop effect in my scene!
and if i use for example two of it - its loks not very good in final!
I did only like this!
https://www.youtube.com/watch?v=HyRk5DLOXXc&feature=youtu.be