Fusion Tutorial - Submarine Part 1


Uploaded by tiltX on 25.09.2011

Transcript:
Hi, I'm Tilt from the pigsfly forums and welcome to another tutorial
Actually this will be the first in a series of tutorials.
The aim of these tutorials is to composite an underwater shot of a miniature submarine.
We'll pull a green screen, fixe jittering in the plate, we'll smooth the camera move
and we'll create a particle system for underwater plankton.
And of course we'll have to develop the underwater look. I haven't
actually finished the shot yet, but this screenshot here for example is from
a recent project. This is how it could look like
with underwater atmosphere and some lights in there.
All the comps and all the footage will be available on my website.
So let's get started!
In this first tutorial we'll deal with stabilizing the camera move.
So we start up with this jittery shot of a turntable
and in the end it'll look like this.
And as you'll have noticed,
we haven't just stabilized the camera move, we redesigned it almost
completely to make it look much more like an underwater camera move.
Since we have the camera track already and we want to use it for 3D space
and various elements further on
we can't stabilize this footage in 2D because it won't match to the
camera track anymore.
The solution is to perform a 3D stabilization as you would be able
to do in Syntheyes for example. But the nice thing is that you can also do it in Fusion.
The result will be in new smooth camera track and the footage that goes along
with it. And we'll be able to use this further on in a 3D space
and integrate it with a particle system and other elements.
So let's get started!
We connect our footage to our imported camera track
and as you can see the camera has an image plane
that receives the footage and
we'll just gonna render that out using the very same baked camera
and of course there's no change to the footage. It's shaky as it used to be.
To stabilize this thing
we're going to create a copy of the camera.
I'm gonna call this Cam_smoothed.
I connect it to our scene.
And I'm just gonna create a new Renderer that will be
using the smoothed camera.
These are the camera's motion splines
and as you can see there's a very bumpy movement especially on the Y offset.
To smooth this, I'll select all keys on all the splines
and in the context menu I select "smooth points" which is Shift-A.
I'll press the shortcuts a couple more times to smooth the splines even further.
This was our original Y position
and this is the new smoother version of the Y position.
However it's still not smooth enough, there's still bumpiness in there
so we'll have to go a step further.
Stabilizing in 3D works a bit like a camera projection.
In a camera projection you project a still image and film it with
a moving camera.
For 3D stabilization of this footage we'll just project the footage
with our original shaky camera and film it with a smooth camera.
What's keeping us from actually changing the camera move in a more drastic way?
And for this i'm not going to rely on the smoothing capabilities of the spline editor
I'm just redesigning the complete camera move.
I'm selecting all the key frames except for the first and the last one
and just get rid of them.
Now i have a perfectly smooth camera move.
You can see what's going on
in the 3D view.
The camera up front is the new camera.
And it will start and end
on exactly the same position.
But the movement in between is perfectly smooth.
However, we have changed the framing quite a bit.
So to improve the camera move even more, we can tweak the splines.
This can be done quite interactively in Fusion's 3D space.
You can look through the camera while playing back the comp and adjust the splines.
Of course if the angle of view is
too different, the illusion no longer works.
This could be improved a little bit by projecting onto geometry instead of a plane
however, there'll always be a limit as to how far you can deviate with your new camera move.
To fix the framing you can even change the new camera's focal length from the
original camera track.
I have tweaked the camera movement a bit more
in the composition that's available for download.
As you can see this
looks much more like an underwater camera move.
However, we are still using the original shot length of 84 frames
and this is because the original footage
is projected by the original camera
for exactly this duration - and the smooth camera I have created just has to
keep up with the original camera.
In our next tutorial we will change this so we're actually even more flexible with
the camera that they want to do.
One important thing if you'd like to try this on a your own shaky camera shots...
...one important thing is the position of the image plane that we're
projecting onto.
For shots like this one where the camera's spinning around an object the
plane has to be where the center of rotation is.
In this case that's the center of the turntable right here.
You have to adjust the depth slider of the camera's image plane while playing
back the footage in perspective view
to adjust the position before you start smoothing your camera move.
If it seems like the turntable's center is standing still, you've found the right value.
In this example 91 looks right.
If your cameras just moving forwards
the position of the projection plane isn't that important.
So that's it for now...
You can grab footage and the compositions on my website.
And I hope to see you next time for the next tutorial.