Courtesy of Simon, from HitFilm
Today it’s all about making guns go boom. See this? This is my BOOMstick!
We’ve already shown you how to film fake guns so that they look real. Now let’s take
a look at how you make them actually do something. We have two shots and two techniques. Let’s
go. Shot number one – here we have stuntman Christopher
firing off controlled, carefully aimed shots. When you’ve got a character shooting individual
bullets like this, you probably want to hand-craft the look, which means using stock footage.
Here’s the original clip. Let’s find a frame where we see a puff of smoke coming
out of the prop. Just before that puff is when we need our muzzle flash to happen.
You can download project files for this tutorial. Click the infocard or check the video description
for the link. We’re giving away a high quality stock clip, so it’s worth grabbing.
OK, so I’m going to create a point layer and position it over the gun barrel. Because
our muzzle flashes are not too frequent I’m not going to bother doing any tracking this
time round – positioning the point manually is fine. I’ll rename it to Barrel.
Then I’ll drop my stop clip onto the timeline. First up I want to get rid of the black background,
so I’ll find the Demult effect in the library and drop it onto the layer. I’m now going
to parent it to our Barrel point, then position and scale the clip until it looks about right.
Too small and muzzle flashes look silly. Too big and they’ll look unrealistic.
Once you’re happy with the position, let’s tweak the look. I’m going to use an Exposure
effect, and bump up the exposure to make it look more intense. I’m then going to add
a Hue, Saturation & Lightness effect, go into the Red channel settings and drop the saturation
all the way down. This stops it from looking quite so day-glo.
Now here’s the interesting bit. I’m going to sling the Heat Distortion effect on. By
fiddling with Distortion and Diffusion Strength we can alter the look of the muzzle flash
without changing it’s overall shape. This is a really neat way to get lots of slightly
different muzzle flashes out of a single piece of stock.
Finally, I’ll put a zoom blur on, which gives the flash a bit more dynamism.
OK, we’re done with the stock. It’s only a handful of frames, so we don’t need to
worry about additional tracking or animation. It looks a bit pasted on, so let’s tweak.
I’m going to add a new Plane layer, above the stock, and to that I’ll add a Light
flare. In the light flare properties I’m going to choose the Sun Glare type, then in
rays I’ll drop the brightness down because I don’t want none of yo rays. In the Hotspot
options I’ll parent the flare to the Barrel point we created back at the start, and zero
out the position so it’s right on top. I also need to change the blend mode, which
I’ll set to None, and then change the layer’s blend mode to Screen.
Then it’s about tweaking the scale to make the flare nice and big. I’ll then activate
keyframing for the Intensity, and over three or four frames drop it down to zero. Finally
I’ll use the Slice tool to cut the ends off the layer, which I’ll delete, to keep
things neat and tidy. So it’s also a good idea in this case to
change the light flare color, to better match the muzzle flash. I’m going to do that by
simply selecting one of the yellows in the flash.
Right, last step. I’m going to duplicate the video layer, and rename the top layer
to Lighting. I’m then going to select the freehand mask tool, and draw a really rough
shape around the front of Christopher, where I think he’d be illuminated by the weapons
fire. Once I’m happy with the shape, I’ll increase the roundness to smooth it off, put
the feather up to hide the edge, and tweak the expansion if needed.
To this layer I’ll add a Curves effect, and ramp the brightness way up – even so it
clips and blows out – while keeping the blacks solid. I’ll then animate the layer’s Opacity
so that the curves adjustment is only visible over the frames when the muzzle flash is happening.
And now we have the illusion of Christopher being lit up by the flash, which immediately
adds a HUGE amount of realism to the shot. It’s one of those elements which an audience
will KNOW is missing, even if they can’t quite pinpoint what’s wrong.
Now, the cool thing about how we’ve set this up is that if we want another muzzle
flash, say over here at this point, all I need to do is select our flare and stock layers,
copy them, and then paste them in over here. Because these copies are still parented to
the Barrel point, all we have to do now is move that point. So I’ll head back to our
first muzzle flash and activate Position keyframing for our Barrel point. Then I’ll go to our
second muzzle flash and move the Barrel point to where it needs to be.
By default we have linear keyframes, which means the point animates between those keyframes.
We don’t actually want that, so I’m going to select both keyframes and switch them to
Constants. That means that the value doesn’t interpolate between keyframes: it’ll hold
on that value until it reaches the next keyframe, at which point it jumps instantly there. Because
our flare and stock are linked to the point, they both move at the same time, which saves
us having to reposition both elements manually. SHOT 2
OK, shot #2. This one is very different, because it’s
a much wilder shot, with more movement, and the character is firing the weapon indiscriminately
and rapidly. Placing individual, stock-based muzzle flashes on something like this would
be incredibly boring. So let’s not do that. We’re gonna get
procedural. First up, we’re going to track the gun.
This is actually a little awkward, because it’s a black gun barrel which frequently
passes in front of a very, very dark background. Tracking a black thing in front of a black
thing isn’t ideal. I’ll create a new tracker using the + icon
next to the Tracks group for the layer. Then I’m going to go into the options for Optical
FLow and ramp iterations up to 50. You don’t normally need to do this, but it’ll help
in this case by giving the tracker more data to work with.
Next I’ll go to somewhere in the middle of the clip where the barrel is visible and
position my tracker over the barrel. Red rectangle define what we’re looking for, green rectangle
defines where we’re going to look for it on each frame. OK, let’s go. This track
does require a bit of manual nudging here and there, but on the whole HitFilm does a
pretty good job of figuring out what’s going on.
OK, skipping ahead, I now have my nice track. Tracking data is just a bunch of numbers until
you do something with it, so let’s create a new Point layer, again called Barrel, and
we’ll assign that tracking data to it. This time, instead of pre-made stock we’re
going to use HitFilm’s Gunfire effect, which can create an infinite variety of custom muzzle
flash shapes. It’s pretty neat. Once the gunfire effect is on the timeline,
I’ll parent it to the tracked barrel point and make sure its position is zeroed out.
It’s as bit diddy right now, so I’ll scale it up to about 360%. So the other super cool
thing about the Gunfire effect is that it’s in 3D, so I’ll adjust its orientation to
point in the right direction – the great thing about this is that you’re not limited to
stock flashes which always tend to point sideways or towards camera – with the gunfire effect
you can handle any angle. Now it’s time to dial in all the options
so this actually looks good. Being British, I don’t know for sure what this kind of
gun SHOULD look like, so I’m going to go with what I think looks cool. Remember that
the effect is totally customisable, so you can make it look like whatever you want.
I’ll start off with the core flare options, tweaking its length, radius and tapers until
I’ve got something nice and punchy. Then with the side flares I’ll reduce them
down to 3, and tweak the barrel gap and barrel angle before adjusting their size with the
length and radius options. This isn’t an exact science.
In Appearance, I’ll switch the texture to Assault Rifle (Daylight). You can tweak the
color if you want as well. Now for the cool bit. Currently our flash
is visible throughout the shot, and looks the same all the way through. I’m going
to go to the first frame and activate the Seed property. THen I’ll jump to the end
and change the seed to something else – the specific value doesn’t really matter. What
this means is that the flash will be randomly generated to look slightly different on each
frame, while still retaining your overall design.
Finally, I’ll drop the rate of fire down, to maybe about 35. This automatically turns
the flash on and off, which is fantastic for a rapid-firing automatic weapon like this.
No tedious keyframing.
This prop weapon didn’t generate real puffs of smoke, so let’s add those digitally.
Conveniently, there’s a preset in HitFilm 4 Pro called Gunsmoke. I’m going to drop
that on beneath our gunfire layer, and then I’ll go in and find the emitter shape and
parent its position to the Barrel point. I also need to do a bit of keyframing work to
the particle system’s Active property, turning it on and off at random intervals so that
the smoke puffs out every now and then. Another good tip for the muzzle flashes is
to add a slight blur to them, because the depth of field on these shots was actually
quite shallow. And that’s pretty much all I need to do,
other than maybe dropping the layer’s opacity down a bit to make it subtler.
The final steps are similar to the other shot – creating a masked duplicate of the video
to create artificial lighting. The only difference here is that I used the Flicker effect to
add random flickering. The same Flicker trick can be used on a light
flare, also parented to the Barrel point. Another good tip for the muzzle flashes is
to add a slight blur to them, because the depth of field on these shots was actually
quite shallow. There you have it – two very different techniques
for creating muzzle flashes. Which one you use depends on the needs of the shot, and
whether you’re dealing with individual flashes or hundreds of the damn things.
That’s all for this week – many thanks for watching, and remember: if you’re shooting
with guns, always inform the police ahead of time and stay safe.
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