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>> I'm going to show you how to put a 3D object
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into your video using the camera
tracking features in Blender.
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And if you want to follow along with me
in this tutorial, click the link below
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to download this exact video clip.
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So open up Blender and go into the
motion tracking tab by clicking here.
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Then here.
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You can either drag your footage in here,
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but I'm going to click open
and select our video clip.
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The first thing I'm going to do is
click on set scene frames so that in
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and out points matches the
length of the video clip.
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Then click on prefetch to
load the clip into memory.
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Then under tracking settings,
I'm going to set the motion model
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to affine and the match to previous frame.
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Affine takes into account the
perspective changes in the shot.
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And previous frame basically just tracks the
pattern from the current frame to the next one.
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Then I'm going to tick normalize.
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This makes sure that if there's
any changes in light
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in the video clip, the track
is not affected by it.
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Now that's done, I'm going to go to the
first frame by pressing shift arrow,
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and then click on detect features.
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Now these boxes on the scene
are tracking markers.
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They track points of contrast within the clip.
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Now I want more tracking markers, so I'm going
to click on this little tab on the bottom left.
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I'm going to change the threshold to 0.1.
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I'm going to change the distance to, say, 50.
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And I'm going to set the margin
from the edge of the frame,
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or the borders of the frame, to about 50 pixels.
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Now if you go into our tracking setting
over here, we need to set the value
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of this margin lower than the
value of the other margin.
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So I'm going to set this to about 40.
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Now, with all the markers selected, I
want to press control T to track forwards.
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Yeah, brilliant.
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Once you've finished tracking forwards,
making sure all the markers are highlighted.
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And if you want to highlight all the
markers, just hover your mouse over here
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and press A. Now I'm going
to press H to hide them all.
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And while still being on the last frame, I'm
going to once again click on detect features
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to bring up all the tracking points.
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And I'm fully happy with these tracking
markers so I'm going to track backwards
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by pressing shift control
T, or control shift T. Nice.
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Next, I want to reveal all the trackers,
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so I'm going to press alt H
to bring up all the trackers.
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Now we have a couple of trackers
that are problematic.
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For instance, maybe these ones
here that follow the cars.
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So what I'm going to do, you
can either delete them manually
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by selecting them and pressing X to delete.
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Or you can also click on solve right here.
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Then select cleanup to get rid of any glitchy
tracks or tracks that have high error value.
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I'm going to click on filter tracks.
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And, as you can see, it's selected
all the markers that are glitchy.
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So all I have to do is hold my mouse
over the footage, press X and delete.
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I'm going to go halfway throughout
the clip and select filter tracks.
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And there's none.
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And just to make sure, I'm going to go to
the last frame and select filter tracks.
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And there's none showing up, so that's good.
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Okay, so next, while still on the solve tab, I'm
going to select focal length and optical center.
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Then for keyframe A and B, so you want to pick
a frame range where the camera is moving a lot
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so Blender can actually track the shot.
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So I'm going to pick a frame range
between 100 to, say, frame 180.
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I've just seen some tracks that are
wild, so I'm going to delete them now.
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Like so. Get rid of this.
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Get rid of that one.
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Yeah, that's cool.
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That's fine.
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Now I'm going to click on solve camera motion.
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And we have a solve error
of 0.35 which is fantastic.
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Any solve error below a pixel is good.
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And anything below 0.5 is great.
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Any solve error above one pixel is
not a good track, I wouldn't use it.
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Now in the scene setup, on the
left, click on set as background.
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And, as you can see, it puts the
video in the background of the camera.
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Then I'm going to select setup tracking scene.
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Next, I'm going to hold shift
and select these three tracks,
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and click on floor to set the floor plane.
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Now I'm going to set the origin of my scene by
clicking this track and selecting set origin.
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Just to make sure that's the middle of
my scene, I'm going to delete this cube
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and I'm going to go into the layout view.
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So I'm going to click this tab.
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Then I'm going to press zero on my
numpad to look through the camera.
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And I'm going to click this little scroll down
button here and I'm going to select 3D cursor.
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Once I've selected 3D cursor, I'm going
to make sure my camera is highlighted.
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And I'm going to place R for rotation and I'm
just going to line up the camera's perspective
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so that the Y direction is going
along the road and the X is going
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across the road, just like that, in this field.
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Just so it lines up like that.
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That's perfect.
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I'm going to select the scroll down button
again and select bounding box center.
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Next, I'm going to change the scale.
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And I'm going to move the plane about here.
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Yeah, that's nice.
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That's perfect.
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I'm happy with that.
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Now I'm going to press space bar just to make
sure that the plane is sticking to the ground.
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Yeah, that looks good.
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Now we can easily put a 3D
object into the scene.
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I'm going to press shift A,
mesh, and select the monkey.
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I'm going to place the monkey so
that it's kind of facing the camera.
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Also so that it's just sitting above the plane.
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Yeah, that's good.
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I'm going to decrease the scale a bit.
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Yeah, perfect.
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Now I'm going to go into render view by
either pressing Z then clicking render.
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Now, as you can see, we can't
really see the video footage.
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But to show the video clip, click
on the render properties tab,
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go to film, then select transparent.
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And we can now view the clip through the camera.
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Now, as you can see, we don't
have any shadows cast.
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That's because we need to bring the ground plane
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from the ground collection
into the foreground collection.
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So I'm going to do that.
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I'm going to change the light to a
sunlight by clicking on this light.
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And clicking on the light
properties and selecting sun.
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I'm going to decrease the
power to about three or five.
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And I'm going to change the angle to match
where the sun is coming from in our clip.
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And I'm going to change the angle
so that the shadows aren't so harsh.
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Nice. Perfect.
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Now there's a lot of other things you can do
to increase the realism of this object fitting
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in this clip, like adding realistic reflections,
lighting with a HDRI, adding blur and glare.
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But I'll cover that in another tutorial.
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There's also several other ways you
can track a more difficult shot,
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and I'll also cover that in another tutorial.
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But, for now, I hope you learned something
new and any questions let me know.
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And I'll see you in the next one.
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Take care.
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Cheers.
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