Hi there - I'm Josh.
Today we're going to be looking at how you can composite a stock footage explosion into
your footage in a realistic way.
Lets do this.
I'm actually going to turn this tutorial over to RodyPolis.
If you've spent any time over on our forums or before the HitFilm forums - the FXHOME
forums - you will know Rody.
He's been with us for over 10 years and he's always been a prolific filmmaker.
But recently, he's turned his attention to making stock footage and he had a wildly successful
Kickstarter and has now created the ActionVFX stock footage packs, which I believe have
been released today on his website, so go and check them out.
There's even some really great free content.
I can't think of anyone better to take you through how to composite stock footage realistically
than Rody, so Rody - show us how it's done!
Hey guys, my name is Rodolphe from Action VFX
And I'm Luke, also from ActionVFX.
We created stock footage for filmmaking and visual effects and today we'll be showing
you guys how we did this shot in HitFilm.
When doing VFX it's important to plan out your shot ahead of time as much as possible.
So don't just go out there, shoot something and expect that to layer in perfectly to your
project.
We used practical lighting in this to simulate fire flicker on our soldiers and our building.
To do this, we basically just used a work light that we got from home depot as well
as Luke's magical hands to DJ in front of that light to get the flicker down just right.
It looked super silly while we were filming but in the end the results are the results.
So lets jump into HitFilm and I'll show you guys how we pulled this off.
So we have the final composite shot open here.
We only use stock footage to create this shot so we can see all the different layers that
we used like the fire, the sparks, some smoke, some lens dirt.
The biggest advantage to using stock footage is that they're usually real effects that
were shot so naturally they're going to look a lot more realistic than a CG simulation.
Alright, lets get to it.
Now, I've already went ahead and got a camera solve for this shot using mocha HitFilm.
You can see that we have a camera here as well as some points that were imported from
mocha.
Since there are already numerous tutorials on mocha HitFilm on this channel, I won't
go into too much detail on how I got the camera solve.
But what is great is that I'm going to use these points as reference to know where I
should place my effects in 3D space.
So lets find the points closest to where the fire will go.
Ground top left is going to be your point since it's the closest to our planned fire
spot.
Lets actually go ahead and rename this point, and we'll go ahead and delete all of the other
points.
I created a folder with some of the different fires from our collection.
We'll actually be using this one right here - the big fire.
So lets drag it into our shot.
As we can see, this fire clip has an alpha channel.
We'll actually need to change something really quick.
So we'll right click on the properties and where it says alpha we'll actually change
that from straight to pre-multiplied.
And instantly we can see that the effect looks a lot better, as it should.
The next thing is to turn this layer into a 3D layer so it can be affected by the camera
motion.
So lets do that.
If I move the playhead a bit, you can see that while the fire layer does move as the
camera moves, it's not perfectly stuck to the ground.
That's because it's not at the right position in 3D space.
To fix that, we'll parent it to a fire spot point.
The reason is, if you go to the transform properties, and you change the positions to
zero, then that fire layer will move to the same position as that point.
Lets actually bring it up a bit - so now if I move the playhead again, you can see that
the fire layer actually sticks a lot better to the ground this time.
It's way too small though, since it's so far back.
So lets go ahead and make it bigger.
Now that our fire is in position, lets start making it look a bit more like fire.
Before we do that, I'm going to turn on this color grade layer that I have here.
The reason I do this is because our background plate - the shot of the soldiers running - was
shot in log.
And it can be very hard to match things right when your footage is so flat.
So this grid allows me to work in a space similar to how my final color graded footage
will look like.
Alright, lets add the curves effect as well as the exposure effect.
In the curves, lets change the channels from RGB to Alpha - that will allow us to adjust
- you guessed it - the alpha channel.
So if I lower this, you can see that the fire starts to disappear a bit.
And if I increase it, then the fire gets thicker and more opaque.
We'll leave it about right here.
So next we'll go to the exposure.
Fire is supposed to be bright so I will up the gamma a bit and I will up the exposure
dial slightly.
Alright - now lets add a glow to our fire.
I usually do that by duplicating my layer and changing the blending mode to screen or
add.
In this case, I'll change it to screen.
Then I just add a blur effect, and blur it up a ton.
I would say about 300 should be fine.
And make sure you uncheck clipped to edge.
Lets decrease the gamma - we can actually put this exposure dial back to 0.
Right yeah, this looks about right.
Now that glow together with our on-set practical lighting does make the fire fit in the scene
pretty well but if you look at the base of the fire, you can see that something still
looks off because the ground closest to the base of the fire doesn't seem to be illuminated
that much from that huge fire.
So lets fix that.
To do that, we'll create a new plane and we'll change the colour to a peach colour.
Click OK - this layer is going to act as our light on the ground.
We're probably going to do the same thing as we did with the fire footage.
Parent it to our fire spot point and we'll go to the transform properties and again,
we'll change all our positions to 0.
Lets make it a little bit bigger.
Next we're going to draw a mask on that layer at the base of of the fire.
Lets go ahead and up the opacity again.
Then we'll go to the blending modes and we'll change that from normal to overlay.
If we go back to the mask settings, lets up the feather at about 70 pixels and lets add
the roundness about 70 pixels or so.
Let me go ahead and decrease the opacity slightly again so it kind of blends in better.
One thing our ground illumination layer is missing, is flicker.
So lets go ahead and bring in the flicker effect in this shot.
So I basically left everything at default except I decreased the amplitude from .2 to
.1 because I wanted the flicker to be a bit softer.
Now lets do the two last steps which are the lens flare and the lens dirt.
Lets create a new black layer and we're going to call it flare.
Lets change the blending mode to screen and we'll go ahead and add a light flare effect
on there.
Of all the lens flares, we'll choose the flashlight LED.
The default color is blue so lets go ahead and go under global options right here and
change the hue until we get about an orange colour.
Lets also desaturate it a bit.
Next, we'll make the flare bigger.
This is supposed to be the flare coming from a big fire nearby, so it's going to have to
take most of the frame.
So this is before the flare, after the flare.
And of course, it's going to need some flicker.
Finally, lets add in the lens dirt.
Lens dirt is great when you're compositing light based effects because they help you
simulate light reflecting off of your camera lens.
So lets go ahead and drag in our lens dirt footage.
About 40% should do it.
And I'll change the blending mode from normal to screen so I can remove the black background.
Lets create a mask on the lens dirt layer around the fire.
I'm making it look uneven on purpose so that it doesn't look too fake.
Lets go to our feather settings and I think the setting I used was about 1000 for this,
and I'm going to crush the blacks a little bit so I'll just add it slightly, I think
it looks great right here.
Next we'll desaturate the layer completely so lets bring in the saturation effect and
I'll take this all the way down.
But lets actually warm up the dirt a bit.
Lets go to hue/colourise effect and basically again we're going to try to find a nice orange
colour.
And I think that fits really well.
The very last thing I did was add a motion blur layer in the scene.
Since our background plate was shot at a lower shutter speed than the fire, adding in motion
blur helps make all the different shots look like they were shot together on the same camera
settings.
So, this is how you take this shot and turn it into this using only stock footage.
What a great tutorial by Rody and his team!
Really useful stuff, I will probably be using that technique in the future.
Do go and check out his website, actionvfx.com - there's fire, smoke, explosions, debris,
particles - all that good stuff, but there's also a bunch of free stuff and we all need
the free resources.
So go and check it out.
If you like this tutorial and would like to see more from us and from other guests, just
comment down below, tell us what you would like to see and please do subscribe.
We shall see you again in a week.
Good bye!