Howdy, I’m Axel from HitFilm, and today
we are looking at creating the impact of a shotgun blast. In an earlier tutorial we looked
at creating muzzle smoke and the effect of a gun being fired, this time we’re going to
look at the other side of that, where someone gets hit by that gunshot. Please download
the project files if you want to follow along, and let’s get started.
Here is the raw footage of this shot, and as you can see, Arris is just jumping backward.
As in our Falling Stunt tutorial, a lot of the impact is created through editing the
clip, and the way this shot is cut together with other shots in the sequence. So, I have
included the project file from our Muzzle Smoke tutorial, so you have something to edit
it together with. Of course, in the actual film, these two shots weren’t edited together
like this, the clip we are working with actually followed a shotgun blast, as the name suggests.
But it will still work for our purposes. So, let’s start by looking at editing this clip
onto the timeline. In the media panel click the Shotgun-Chest
clip, and it will open in the Trimmer. The Trimmer allows us to easily select a specific
portion of any video clip for use. We can preview the clip, by playing it, or by scrubbing
the playhead beneath it. Find frame 9:07, just before he jumps backward, and we will
set our In point, either by pressing this button, or by pressing I on the keyboard.
Then press the spacebar to play, and then again to stop once he has landed, and we will
set our Out point, using this button or the O key. The I and O keyboard shortcuts, for
setting the In and Out points, work on the Trimmer, the Viewer and the timeline. Now,
drag our selection from the Trimmer onto the timeline, and snap it to the end of the existing
footage. Now if you play that through, it works ok,
but we want to trim this a bit further so it feels more like he is being blasted back,
not jumping back. To do this, and to add our effects, we will move to a composite shot.
You can easily convert any clip on the Editor into a composite shot for further compositing,
by simply right-clicking the clip and choosing Make Composite Shot. Our clip and timeline
use the same resolution, so either one of these options will work, and we have no effects
or transform adjustments present yet, so the lower options don’t apply, just click OK.
Now we have the clip on its own timeline, and we can trim a bit out where he is jumping
backward. Advance three frames, using the period key, and here we will cut the clip.
Select the Slice tool, which you can do using the C key on your keyboard, and slice the
clip at the playhead. Then press V to switch back to the selection arrow. On the next few
frames his head is turned, as he jumps back, so advance to frame 10, where he is once again
looking forward, and has some backward momentum going. Drag the start of the second clip over,
using the double-arrow trim tool, to trim it to that frame. Then, drag the entire clip
over, using the single arrow move tool, to close the gap. Both these options are in the
Selection Tool, but they are contextual. By default the Move mode is active, but as you
move the cursor near the end of a clip, it will switch to Trim mode. Now if we scrub
through, you can see the movement is a bit better, but there is an obvious jump there,
due to the camera moving. So we need to adjust his position so that he lines up properly.
To do this, we will first use a mask to remove most of the frame. Use the freehand mask tool,
select our layer, and make a selection that includes the edges of the wall, the roof,
and the second post here. Since our character is moving, we will use these stationary edges
to get a good alignment. Once the mask is closed, we need to replace the area we removed,
so trim the start of the second clip back to the start of the timeline.
Now we will use a fun trick to get perfect alignment. Your first thought might be to
reduce the opacity of the top layer, so we can see through it and align them, but here’s
a way that works even better. Right-click the top clip, and set the Blend to Difference.
Difference blend shows us exactly where the edges of objects in the layers are different.
Zoom in on the viewer using your mouse wheel, or the Zoom menu, onto the finer details on
this post. Then we can move the layer, either by dragging it or using the Arrow keys on
the keyboard, until it turns black when we get perfect alignment. With difference blend,
once there is no difference between the layers, the edges disappear, so when everything goes
black, you know you have perfect alignment. Once the alignment is perfect, open the Transform
properties for the layer, and enable Keyframing for the Position property by clicking the
circle just left of the Position name. Then, we will check each of the other two frames
where this clip is visible, and ensure it is properly aligned on every frame. Just adjust
the position on each of them until the edges disappear into black.
Once we have all three frames properly aligned, we can set the Zoom back to Scale to Fit,
to see the entire frame, then right-click the layer and change the Blend back to Normal.
Now if we scrub through, our alignment is lovely, and we have a much stronger impact,
more like he is being forced backward. Let’s soften the edges of our mask a bit, just to
ensure the edge isn’t obvious. In the Mask Shape controls, set the Feather Strength to
10, and that will do us nicely. If we switch back to the Editor, and play through that,
we can see it works pretty well just as it is.
Some of our more astute viewers might notice the jump in his movement caused by our editing,
though. The alignment is good, so the scene doesn’t jump, and a lot of viewers won’t
notice anything, but he does perhaps move farther in this frame than he ought to, so
we will give the viewers something else to look at and tie this together with some effects.
We are going to use this Blood Mist clip, which is one of the free effects available
from ActionVFX. They have a bunch of other stock footage effects you can download for
free, and a bunch of amazing clips you can purchase as well, so do visit their site to
check it out. But do that later, right now we are going to add this stock footage. Load
the clip into the trimmer, and let’s remove these first frames where it is being sprayed
from the side. Set your In point, and drag the clip onto the timeline. We want it to
start on the second frame, where the timecode says 01.
Now to remove the white background, right-click the clip and set the Blend mode to Multiply.
In the same way that Screen is effective for removing black backgrounds, Multiply works
well for removing white backgrounds. Now open the Transform controls, set the scale to 20%,
and adjust the Position so it is over his chest. Then we will want to animate the scale,
so this mist gets larger rather than just appearing suddenly. Enable keyframing for
Scale and Position then advance one frame, and set the scale to 50%, and readjust the
position so its is realigned over his chest. Because the effect is not perfectly centered
in the video clip, we need to keyframe the Position as well to maintain alignment. The
effect lasts too long, so enable keyframing here for the Opacity, then move the playhead
to frame 15, and set Opacity to 0. By adding an effect like this which spans the cut in
our footage, it helps tie the two halves together, so they feel continuous.
Switch back to the Editor timeline now, and find the last frame where our image is visible.
Trim the end of our Shotgun-chest comp back to that frame. When we trimmed the center
frames out of our clip, it ended up creating a gap at the end of the comp, which is what
we just removed. Now select both composite shots on the timeline, right-click and select
Proxy – Make Proxy. Rendering proxies will combine all the layers contained in the comps
into a single render that can be played back more easily. The progress is shown next to
the comp in the Media panel. Since these are fairly short, fairly simple composites, the
proxies should render pretty quickly. Once they are done, play it back to see how it
looks. Hopefully you have watched our Muzzle Smoke
tutorial as well, to see how the first half of this sequence was created, and to better
understand the editing aspects of sequencing these clips, and how they dovetail together.
If not, please watch it now, along with our other Westworld to Yuma tutorials. And that
wraps things up. So long, and thanks for watching.