- [Instructor] Okay, let's clear that out
of the property bin, and cruise back over here
to look at something very important
about our ScanlineRender Node, and that is the BG input.
Now, we've talked about this before.
The BG input, if it is left unattached,
will take its size from project settings.
So clearly, my project settings are for HD_720.
If you hook up an image, or a reformat node,
you can change the render that you get
out of the ScanlineRender.
It'll override project settings.
Let me open up this Reformat Node.
Right now it's set the same as project settings,
however let me switch it to, let's say, 2K_Super_35.
Boom, okay, now look at that.
2K_Super_35, okay?
There is a trap here I wanted to warn you about.
I'm going to switch over to the 3D and select my camera
and lock the viewport.
And of course, the 3D side
is going to report 2K_Super_35, okay?
However, let's say I switch back to HD_720.
Nothing happened.
The 3D viewport is unaffected.
Tragically, what you have to do is slap it upside the head
by switching back to 2D, ah, there we go,
and then back to 3D, ah, there you are.
Next, let's take a look at the MultiSample tab.
So let's clear our property bin.
Double-click on the ScanlineRender Node
and cruise up to the MultiSample tab.
This is where you set the Motion blur for your character.
Let's switch to our 2D side.
I'm going to push in kind of tight here.
I've got antialiasing turned off to speed things along,
so don't worry about that.
First of all, are the samples.
What it is going to do is literally render
multiple samples of every frame.
So, maybe I want a sample of five
to get the amount of motion blur.
This is another one of those parameters
you want to be very careful with.
You want a high enough value to get you a nice motion blur,
but you don't want to overdo it,
because motion blur is computationally expensive,
just like antialiasing.
So you have to set it appropriately for every shot.
I can turn this up to ten,
and I'm going to get a much smoother motion blur,
but I'm going to pay a terrible price.
Now, to change the amount of motion blur,
in other words, the sample is your quality control,
but not the amount.
The shutter is the amount of motion blur.
If I want less motion blur,
I might drop this to 0.2, okay?
So the shutter is only open 20 percent of the frame time.
Back to the default, 50 percent.
Now, 0.5 is equivalent to a 180 degree shutter
on a film camera, if you're familiar with film cameras.
If you're not, it's still equal to 180 degrees.
If I turn that shutter to a one, that means 360 degrees,
I'm holding that shutter open
for the entire length of the shot.
So your stuff is all going to be mushy and blurry
and streaky and smeary.
If you set the shutter too low, you'll get motion strobing,
things will have kind of a staccato type look.
The shutter offset sets when the shutter opens
for each frame.
At the start of the frame,
perhaps it's centered on the frame,
or it's at the end of the frame.
Or you might want to do a custom,
but the default is the start of the frame
and you really don't have much reason to change that.
Now, the randomized time, and the sample diameters,
the focus diameters and of course stochastic samples,
these are all rather advanced concepts
you normally don't have to worry about.
Okay, let's go take a look at the Shader tab,
which is right up here.
Now, the Shader tab defines which AOVs,
or arbitrary output variables, you're going to get rendered.
By default you're going to get that forward pass.
Let me show you what you get by default.
First of all, of course, you're going to get your RGB pass.
Next, you get your alpha pass, of course.
Then you're going to get your depth pass.
Let me show you a little clearer here
that this really is a depth pass,
there you go, now you can see your depth, right?
Okay, so let's put that back to default.
And you're also going to get the forward UVs.
These are the motion vectors that are put
into the foreword channel.
Now those are all by default.
You have two more variables that you might want to have,
one is the, what they call surface point,
which is the same as the position pass,
and the other one they call surface normal,
which is the same as the surface normals pass.
All right, to do those,
first, you have to turn on output vectors.
Next, let's go to surface point.
You have to give it your name.
So, click to new and say,
I want to call this myPosition.
Now, position passes get not RGBs but X, Ys and Zs.
So, do an x, y and a z.
Now, if we go look over here, look,
I have a position pass which I did not have before.
All right, let's go to the surface normals.
And again, we're going to have to say New.
I want to call this MyNorms, also an xyz, x, y, z.
Okay, now we'll go over here and MyNorms.
There's my surface normals.
Okay, we've got a nice inventory of lighting passes
and AOVs, but we got to make sure
we write them all out to disk.
We don't miss any of them.
And for that we're going to use an EXR file.
So, let's take a look at the Write node
and EXR files vis a vis the ScanlineRender Node.
So I'm going to select ScanlineRender,
come up to here and do a Shift + click on the Write node.
By the way, FYI, the reason I didn't
simply punch up w to get a write node,
is when you do the w on the keyboard,
you cannot do the Shift + offset gag, so remember that.
Okay, so let's put this back
to a normal RGBA type of a display.
So let's pretend that I need
to write my mantis character out to disk
and I want all those lighting passes
that I setup in my ScanlineRender node, okay?
So I'm going to start by hooking my viewer
up to the Write node.
This is critical.
The Write node at the moment just says RGB only.
If I were to do a render, I would have no alpha channel,
no depth, no nothing, I'm just going to get RGB.
I have to set this for all.
Now I'll get my alpha, depth, forward, warms and position,
but not unless I set it in the Write node.
So with all your channels properly selected
in the Write node, you can then fill out
the path name and the disk name and all like that.
Okay? Okay.
So the ScanlineRender node is Nuke's 3D renderer
and controls antialiasing, motion blurs and AOVs.
Always remember to connect your viewer
to the Write node so you can double check
that you're getting what you want rendered to disk.