- Hello and welcome.
My name is Ben Brownlee for Boris FX.
And in this Particle Illusion tutorial
we are looking at rain,
and how to create a more realistic rain emitter.
So we're gonna be taking some of the lessons
we've learned previously,
and then putting them all together,
to look at the different elements
that go into making up a more convincing part of rain.
We're gonna be looking at some stuff
that we haven't seen before,
and also some common uses for deflectors,
and how we use the over life capabilities
of all of our particles.
So without further ado, let's get wet,
and look at raining Particle Illusion.
(gentle music)
And like several times before,
let's start off in Particle Illusion
by doing a search on the presets for rain.
And we have a number of different presets already here,
and different sorts depending
on what kind of rain you actually fancy,
whether it's some more kind of cartoony rain,
including our own traveling little cloud,
that's actually kind of cool,
or my clouds of menace,
or something a little bit more realistic,
that we have here, I think these work
better with a bit of motion blur,
or a bit of torrential rain there.
So we do have some options
within the emitter library already.
But I think it's going to be important
to find out how to make your own rain.
So I'm gonna just start with a basic emitter.
We'll apply this to the stage.
And because it's rain, we need it to do a couple of things.
The first thing we want it to do is to be an area emitter,
or at least a line emitter.
So, if we do that there, we can create
some rain falling down from the sky,
so I'm gonna place it very close to the edge here.
And at some point in the future,
I'm gonna then lift it above,
but I think it's important now to be able to just see
what our particles are doing.
So if I play that back,
they're not really doing anything.
If I come into the particle,
let's have a little look and change this up.
The reason it's not really doing anything
is because the particle itself
is only moving very slowly.
It's got 12 velocity, which isn't very high,
and we got zero weight.
So as soon as I add a bit of weight,
we're gonna start getting some gravity.
There we go.
If you have a low velocity and not a lot of weight,
let's see what happens.
Well, our particles are spat out everywhere.
And the reason for that is because our emitter
is set for an emission range of 360,
which means that when the particles are born,
they could go in any direction whatsoever.
So if I bring this down,
so we have our emission range at maybe 12, 13,
and then zoom my emission angle around 290 degrees.
Then there's another way of just getting
particles to fall down.
And if we need torrential rain, a rain that moves very fast,
having a combination of high velocity and high weight
is going to give us a more interesting effect.
We can then come down and do the velocity variation,
and the weight variation to give our particles
two different ways of being random.
Okay, let's turn that motion blur on on there,
and you can start to see,
we're getting something that looks
a little bit more like rain.
You see, because our particle is moving so fast,
we're getting a lot of separation with the motion blur.
That means we'll just have to go
into the project settings and turn
our total frames on their motion blur up.
Turn that to 16,
we get a much more realistic result without that separation.
I would always counsel to get that total frames
motion blur number as low as possible,
because the higher this number is,
the more particles we have to generate,
and the slower everything becomes.
So it's a rule of thumb, we take that particle number,
that's at the top, and then multiply it by the total frames,
to get the total number of particles
that have to be generated.
So whereas it might say 1,000 particles up at the top here,
if we have a motion set to 16,
that's gonna be 16,000 particles
it's going to have to generate.
See if we can get away with 10,
10 we're starting to see a bit separation again,
so let's bring it back up to 12.
In the previous tutorial we've seen
other ways of making this go faster,
and one of them is just to reduce the life of our particle.
So that it just sits by the bottom down here.
Now, I'm not gonna do that,
I'm gonna leave that life back at 10, where it started,
for one reason.
And that's because we're gonna add a deflector to this.
Let's turn off motion blur so we can see this a bit better.
And I'll bring my emitter a little bit further up,
so we can't see that anymore.
And let's come in and rename my particle now to rain.
I'm going to go into my properties,
and I'm going to change my shape image.
And I know that if we look at the emitters 2020,
we actually have quite a lot of good rain drops.
So we have water drop one of five here.
Or we have 13 here,
or 18 here.
So we have quite a few to choose from.
And these shapes are actually quite big, 256 by 256.
So if I was creating my own raindrops
and I didn't want to use the ones in the library,
and I only wanted my rain to be quite small,
then I would definitely not size them at 256 by 256,
that's too big.
But Particle Illusion is very efficient
at throwing around lots of this size of particle,
so we're actually gonna be doing all right.
I might zoom in a little bit.
I'll come into my Edit Mode so we get even more space here.
So we have a variety of raindrops going on,
and in our shape object,
we need to tell it to use a single frame,
so that we're not animating those,
and then it all turns in the same shape,
but if I go random start frame,
we're now back into random shapes again,
now those 18.
Because these are moving so fast
and their motion blurred up quite a lot,
the shapes do tend to lose their relevance a little bit,
but by using the raindrops,
we do get very natural fall offs
that we otherwise might not get.
I'll turn my opacity up a bit,
so we can see those a bit better.
Okay, so we have our basic drops falling down now.
And, of course, we can have it even rainier
by just turning up the number
of particles that we have.
So this is now a complete downpour.
I'm gonna bring this back to about 23 there,
yeah, that's looking all right.
And we'll look at some other tricks
to fill this out a little bit later.
Now we're gonna add a deflector
to start off our splashes.
Let's turn off our fair motion blur there,
gonna add a deflector.
And the deflector is just gonna be near the bottom,
so two clicks and then hit escape.
Let's get rid of that.
And see, I've started my deflection 115 frames in,
so I'm just going to drag that back
to the start frame.
And we'll play that back,
we can see the raindrop bouncing up and down.
We don't want it bouncing this high,
so what can we do with this?
Well, we can do two different things.
We can either turn the bounce down,
so it's just looking a bit like that,
or we can also bring the life down,
so the particles aren't living as long
to be able to splash as much as they are.
So if I'm bringing my life down to eight,
you see, we're not getting as many splashes
or as many bounces because as soon as they finish bouncing,
their life is over and they disappear.
Let's add a little bit of life variation to it.
There we go, let's turn that to about four
just so we get a little bit more randomness again,
big one for randomness.
Let's turn on the motion blur,
and you can see them bouncing around a little bit now,
splashing off.
What if we wanted the ground plain
to look a little bit more tilted?
Well, here we would just come into the deflector,
and I would change the thickness of that deflector up.
Let's move our deflector points up a little bit as well,
and let's see what effect that has.
So now we've got a chance of those particles
hitting at any point between these two lines.
So it's making our ground plain look a bit fatter.
So the splashes are looking alright for now,
and we'll tweak this up as we go.
But I want to add some proper splashes,
some animated splashes if I can.
And this is the nice thing about Particle Illusion,
it's that we can add multiple shapes,
coming from the same emitter.
So if I come to my rain,
and I'm just gonna duplicate this,
and I will call this one, let's rename it,
and call this one splashes.
And I'm just going to turn off
and disable the main rain.
Okay, so let's come in and change my shape,
and let's find some splashes.
And if I come down to water,
and I have a few little different splashes here.
Again, if he wanted to make an animated splash,
we can do that, and import that in ourselves,
but I'm quite happy just to use
a simple splash here.
I'm gonna turn off motion blur
so we can see what's going on a bit better.
Let's zoom in.
So our splashes are very small,
very, very small.
So, I'm gonna turn those splashes up.
And there we can see them splashing in,
splash, splash, splash.
Doesn't look amazingly realistic right now,
but we're trying to sort that out.
If we change the behavior on the particles,
at the moment we're specifying a particle angle,
so all the particles are in the same direction,
and we specify that down here with this angle.
But probably just specifying the angle
would be better for this one here.
There we go.
So now these are falling down
and hitting in the right place.
Or I should say hitting in the same place
as our rain.
Splish, splish, splash.
But that is not looking very realistic yet,
so I'm gonna take my number down,
'cause we don't want that many splashes.
And we're gonna do some interesting stuff with this,
because I'm gonna come down and have a look
at the over life values that we have down here.
And we've seen these values a few times before,
but these are a great way of limiting
when and where particles are visible
within their lifespan.
Because we don't want the splashes
to be visible all the way
from when they're coming down here,
and then splashing up, we don't want that,
we don't need that, that doesn't look good.
So if I change my size over life
to about, we'll take it about 70% of the way in,
and I'll add a keyframe at 100% there.
And I'm gonna drag this other one,
and we'll drag it down to zero.
I'm gonna take life variation down to zero as well,
so we can actually see this a bit better.
Let's go size over life again.
So now we can see that the splashes are only visible
for the last 30% of their life.
And that's still too much.
So if I drag that over to not point nine,
we only really want these visible
when they do the last little bounce.
So if they're visible from up the top,
then we've got this in the wrong place.
And that's looking better.
So let's play that back.
So now they're only hitting
when they're on the ground plain.
So let's give this a bit variation.
Let's take our bounce down to one,
and our bounce variation up to five.
And we've got our spin set to zero,
let's get our spin variation set
a little bit here as well.
So that as they hit, they're gonna hit
in slightly different directions.
And we've also got spin over life.
So what I can do is I can do the same thing
as we did previously, I can take my keyframe
over here to about the last 10% of their life,
drag that up so they're only spinning
for that last 10%.
That might be a little bit too much in this case,
let's drag that backwards.
I'm not actually looking
as I'm dragging this along,
I'm just looking for any kind of subtle movements
up in the stage.
That's it, and I'll add a little bit of variation
to things like the size, take my main size down again.
A little bit of variation to the size,
and velocity variation,
I think we'll keep that where it is.
Let's see what that looks like with motion blur.
If we're seeing too much blur down here,
and it's looking distracting,
probably means we need to change up
the size over life a bit more.
Add another keyframe there,
and just back that off a little bit.
So it's gonna grow very quickly.
Might even have it so it grows a bit bigger,
and then comes back down to 100% again.
Okay, and let's see how that looks
with the rain enabled as well.
And now I can just tweak my size over life
a little bit more so that it's looking better.
Cool, when I'm happy with that,
I will take the opacity on the splashes down,
and we just got a bit of variation going on
on our particle system here.
If I want to, I can also come into my regular raindrops now,
and I can change their size over life,
so that as they splash down, as they hit the deck,
again around about 90% of the way in,
I can take their size down
a little bit towards the end of their life as well.
So we don't end up with lots and lots of rain splashes
that just disappear off.
We actually have them animating off
at the end of their life.
And that should look a little bit nicer.
They're still a little bit bouncy for me,
let's take the bounce down.
And because both of our rain and our splashes
can now be controlled by the emitter itself,
if I wanted more or less rain,
all I have to do is turn up my number
in the emitter itself.
And that will give me more or less raindrops.
I'll also change the frames to preload
to around about 100.
So we will start with a little bit of rain
at the beginning of our animation.
And one last little thing,
if I change my bounce over life as well,
I can try to get my raindrops hitting once,
and then almost dropping dead on the floor.
So, very simply, we can create
a much more natural-looking particle emitter system
by using variation on that particles,
and also by using the over life graph
on our particles as well.
And I think giving a little bit more time,
we can use these same techniques
to add in another couple of particle types in here
to give us an even more natural-looking system.
If you want to learn more about Particle Illusion,
then we have a huge number of other tutorials
for you to get to grips with,
whether you just want to learn more about the graph field,
how to change up your emitters,
or how to put together more complex particle systems.
We've got something for you there.
But thank you for now.
My name is Ben Brownlee for Boris FX,
and I'll see you again soon.
Download Particle Illusion standalone for free
at borisfx.com.
Including thousands of free emitter presets.
Continue watching this Getting Started tutorial series
to learn more about what you can do
with Particle Illusion.
And find out more about the plugin version
of Particle Illusion, with extra features,
including built-in Mocha Motion Tracking
at borisfx.com.