- Hello, this is Mocha Product
Manager Martin Brennand and today we're going to
be getting rid of a man. There's always one. That extra who wanted
a bit more screen time, the relative you didn't expect to turn up at the wedding video, or in this case, the random bystander who
gawks at the filming going on because the council wouldn't let you close off the street for a simple shoot. At any rate, this is what the Mocha Remove Tool was designed for. Getting rid of things and
people who shouldn't be there. The main problem with
Mr. Standing-McGawker over here however, is
he's always in one place. So the only option we have is Cleanplates, I.E we're going to have
to paint him out ourselves and then let Mocha handle the rest. Our shot today is provided by Pond5 who stock a pretty amazing
selection of video. So, to start off, inside After Effects, we're going to load the Mocha effect and then just click the large,
friendly button at the top. This loads our Mocha GUI
and we can get started. The first thing we need to do is roto out the actors shoulders so it
doesn't interfere with any of the other layers we need
to make for this remove. We will choose the X-spline tool, to draw our shape and
roughly get the outline, making sure to trek outside the edges rather than internally. We're 'gonna do a basic shear track as there isn't a lot
of perspective change. We don't care to much
about plain accuracy here because the shoulder is an organic shape and will naturally fall off
to reveal more of the sides. The rest of the shoulder we'll
just have to tweak manually. So once we have our shape
and our parameters set up, we can now go ahead and track forwards and just adjust the shape as we go to make sure that it still
fits over the shoulder. After a point, the shoulder is
no longer going to interfere with the remove, so we can
stop and trim the layer down. There's no point in doing more work than we actually have to. Rather than refining this
roto at this point however, I'm going to leave the
rough shape for now, because I want to make
sure it doesn't interfere with the next couple of tracks. The next important track is the bystander. We're gonna grab our trusty X-spline tool and draw this shape as close as possible to what we want to remove, so we don't need to clean up as much. We then drag the layer
below the shoulder layer, as Mocha machines top layers
are in the foreground, and lower layers are in the background. Very importantly, you should also remember to turn off previously tracked layers, it's good to get in
the habit of doing this so that you don't accidentally
re-track layers later on. I'm also going to turn on track mattes under the matte view button, so we can make sure the shoulder is always being cut out
of the bystander track. We then track our bystander
layer backwards and forwards from the drawing point to
get the overall motion. The good thing about this bystander is he's actually standing still, so there's not much
additional roto to do here, and it's much easier
than the shoulder ones. For the final layer, we need
to draw a background layer, now I'm doing something slightly different to normal cases here,
in most Mocha removes, you'd be encouraged to
track all the planes in the scene that make up the background, in order to get accuracy. The wall, the floor and the back plane, this is because parallax
in a lot of moving scenes will make you remove disjointed, if you don't track the individual planes. Here, because the background is so blurry, and we don't have much obvious parallax, we can just wing it
and use a single layer. The point I want to emphasize here is that you should make Mocha
work for you as you see fit. Sometimes breaking the rules helps you rather than hinders you,
and in the case of removes, if the audience never knew it was there, their not really going to look. So now we're just 'gonna do what we did for the previous layer. I'm going to drag my layer down
to the bottom of the stack, I'm 'gonna turn on my track
just so I can see that cutout, we'll rename our layer
to something interesting like Background, and I'm 'gonna turn off the previous layers cog. So we're 'gonna set the Minimum Percentage of Pixels quite high,
and we're also gonna turn the surface and the grid on. This is really important
to see how the accuracy of your background track is going, because the background track
is the most important one to get the tracking accuracy correct, otherwise you're 'gonna
get artifacts and problems in your remove, so we're just making sure that's tracking correctly
throughout the shot, using that Surface and Grid tool. You'll also notice here that I need to extend the shoulder timeline
that I trimmed earlier, as it's still interfering
with the background track, the good thing is you can re-extend and keep moving your
layers around as you go, so there's no harm done. Once we've finished
refining the shoulder matte so that the track is no
longer interfered with, we continue on with our
background track until the end, and then just quickly
scrub through the shot to make sure the track
is looking accurate. So, when we play it back, you can see now that this
track is nice and accurate, the grid is showing us that it's not bouncing around to much, so we're 'gonna get a good
remove off that background plate. Now, what we need to do,
is fix up that shoulder, so that it is accurately
against the shoulder edge, because this shoulder edge is going to be cut out of
our final remove patch, so now we just need to go back and refine all of that matte edge to
make it nice and clean. To refine the shoulder,
we're going to turn on the Quick Stabilize mode, which will simply take the
tracking data from our layer, and lock its position based on the motion. This makes it much easier
to work with moving objects while we're refining an edge. Then using the point insert tool, we're going to go though and find all the little bumps and dips in the jacket to make sure
they're covered accurately with additional control points, smoothing those curves out where necessary using the X-spline handles. If you're having a hard
time seeing the edge, you can turn off the
colorize mode in the mattes, which will cut the area
out for easier viewing. You can also turn on invert
matte, in the layer properties, to see if any of those edges
are bleeding out of the shape. Using a combination of these views, we go through and refine the shape throughout the necessary covered areas. When you're done, you
should make sure none of that edge is peeking through, or it may be used as
part of the remove render and show odd artifacts. Once all our layers are primed and ready, it's time to select our bystander layer and move over to the Remove module to set up the parameters,
make sure the first and last frame parameters match your
project in and out points. This will avoid it referencing
frames that you're not using. Also turn on auto step, this
is not always necessary, especially since we're using cleanplates, but in other cases, it saves you having to manually work out
which frames to step over. By default, the frames before
and frames after values, take the max range of the clear. So, we want to reduce this
down to a more realistic value, here there are actually less
than 100 frames in the clear, but I'm just 'gonna set it to 100 as that will be fast enough for my needs, and Mocha is smart enough to stop looking if the frame count ends before that value. Now for the tricky part, since
our bystander is not moving, we need to paint him out manually. There's not much we can do about this, but we'll just have to save out our cleanplate and get painting. We want to find a frame
that's as close as possible, but doesn't obscure any detail. Here on frame 454, we
get up nice and close, and we can still see his feet, so it's a good place to start. To far forward in the sequence and it doesn't have much detail, so all we need to do now
is hit the create button, and save our Clean Plate out to disc. Over in Photoshop, we can now begin the Cleanplating process. I'm not going to show you
the whole paint process here, because frankly it's 'gonna
vary so much from case to case, it's not worth going into to much detail. The main thing is I tend
to use a combination of the clone stamp tool
and the patch tool, and you want to try and
grab samples as close to the offending object as possible, so you maintain detail in the blur without looking repetitive. So here's our final result painted out, we just need now to save this
and go back over to Mocha. So, if we go back to frame 454 and look at our cleanplate, we can now see it's painted
out on the right frame. If we open up the edit dialog, you can see that our frame
is in the cleanplate list, and we can enter this list if we need further frames down the track. The next thing I'm going to do is check Use Cleanplates Exclusively. There is literally no point
in not checking this option, because we can't reference anything else in the background to
help remove this shot, this will also improve the rendering performance significantly, because we're not needing to check any other frames for reference. Now I'm going to do a test render back on the first frame of the sequence to see how it's looking. First up, we'll turn off our overlays with the button up here, or use the short cut back tick key so we can see the shot without
the lines being in the way, and then we can click Render. As you can see here,
it's not looking great, there's a definite edge to the patch, this is because we're using a single plate across the whole shot and the light is varying over time as the camera moves. So this is where we start
using the illumination tools from top to bottom to
find the best results. Let's first try with linear. Linear is a nice way to
adjust lighting progressively through a shot, and here you can see, this isn't really helping either, the light being pulled in is actually darkening our shot to much. So now we're gonna try
interpolated illumination, which will be much better at looking at the subtle changes over time. Now, keep in mind interpolated
illumination modeling is much, much more performance intensive than the other rendering modes, as it's calculating how light is changing on every single frame, however, it's a lot faster when using
Cleanplates exclusively, because again we're only having to reference specific frames. So rendering with this on, you can see we're getting a
much more realistic result, there's still a subtle halo edge here, so I'm gonna fix this by
turning back on our spline, and selecting all the points, then adding some edge
width to the remove shape to pull it out a bit further. Now when we render the remove, it's much cleaner and we
can test a few more frames to see how it's looking across the shot. This looks good, so it's
time to save and close, and then render back to
the main host timeline. Back in the After Effects interface, we twirl down the module render section, choose Remove from the module
drop down, and click render. So, removing unwelcome people from video is easy enough to do with
the Mocha Remove module. It saves you the hassle of a re-shoot, and then you can get back to more interesting tasks, like invoicing. If you have any questions, as always, please jump over to the
forums at www.BorisFX.com. Thanks for watching, and goodbye.
