All language subtitles for 3月5日 (7)

all right so this is a class 3 nuke file

and we're going to talk a little bit about keyers

now this is an advanced tutorial

but I want to make it available to even beginners

in the sense that

I want to introduce you to a little bit of the

most famous keyers

the big top 3 obviously are primat

and of course there's the other one key light

and finally there's the Dynamic Duo

IBK Gizmo IBK Color

so these are the biggies right here

some people

do prefer sometimes to use Ultimat

which is another one which actually couldn't

basically take out any webbing

that would be involved in

certain areas around a character

if you're trying to create a Cormat and so forth

so it does give you some really cool results

a little bit more complicated

but the big ones are primat

key light and these two

these two are usually good for fringe mats or

commonly called edge mats as well

and primats are usually good for core mats or

kind of hard

cores that we're going to create which is the

center piece that fills in the

Swiss cheese holes of your atypical key

so let's go ahead and just kind of poke around

with a couple of these here

let's go ahead and start with key light

alright

so I'm going to go ahead and take this footage of

Jessica and we're going to go ahead and plug it in

as you can see you have a

background outmat in mat source

I am not going to get in heavy detail to any of these

because I want you guys to go straight to production

when I started in production and game design

I didn't have like theory or ideas or

maybe you could try this with this

maybe this will work

in production

you literally are thrown into

the lion's den and you got to fight off the lion

and that's just basically the process of production

and we were given templates and you know

best course of actions that you could

say are very linear with

not many options

but for the majority of the sake they work

so I will be introducing you to the Uber key

which will be a templated

key which will have all of these pieces

but

just to be aware of how the mechanics of these work

I'll just go ahead and put in source here

to our footage

and there's plenty of

tutorials on YouTube in regards to

learning about this

I'll talk about them a little bit later

but I'm just going to go ahead and

put this into the viewer

and here you can see we have our scene here

and you can see if I go ahead and slam the gamma

we have a variation of luminance in the green

so you can see we have a variation in say

the actual luminance

it's brighter over here

it's a different value

so if I were to

click Ctrl click you could see the values of red

green and blue

are different than here

this is like point seven two in the green

it's point five here

it's

04 in the red over here it's 02 in the red over here

and over here it's like

006 and over here is like 04 in the blue

so there is a variance in color information

between these two areas

so key light is good for scenes where

there's a locked down camera and

you don't have the camera moving a lot

where the background plate would actually change

so if you have a locked down tripod shot

where the person's just walking along

and the camera doesn't pan or tilt or dolly

this is probably the best tool to use

sometimes for here detail

but again you can get this done as well

with certain situations with IBK

coloring gizmo which is the

most popular of all the keys

so I'm going to take the

key light and click the little

screen color here

and I'm going to go ahead and hold down shift and Ctrl

and you can see

how it starts to do the disco here where it goes back

and forth and I want to hold down Ctrl alt

and click if I hold down

shift Ctrl and Alt this is on a PC

I'm sampling the original image

if I don't hold down that

I'm going to get this and sampling the sample

so I don't want to do that

I want to make sure it's sampling the original footage

and ignoring what has been changed

so I went ahead and sampled this area

and usually you want to

sample area that's very close to the wispy

here's

now if I hit a for alpha

you can see we have a pretty good reality here

you can see the difference in luminance

it's all based on the pixel value that we chose here

so whatever the chrominance value

RGB of what we chose here is what it's keying

and you can see it just degrades over here

now if we choose this area over here

you can see it does a really good job

but we might be losing some details

remember you can win the battle but lose the war

when it comes to king

you want to have that yucky

mucky motion blur

and you want to have these fine wispy details

so you can see just by poking around

again I have hit a for Alpha to

look at my alpha

I can kind of choose something

that's a good middle ground

but one thing you notice if I go over here and go

oh that looks good

you'll notice I've lost detail in the hair over here

so if I click over here

you can see I've gained this extra strand of here

so this is going to require

a little bit of finessing

so I'm going to get kind of close here

and you can see I've got all these nice here details

and at this point

we can go ahead and just do a couple things

such as screen gain

which is going to

kind of pump that up just a little bit

you can see it's starting to eat away at the hair

which we don't want to tamper a lot with keys

I know it sounds kind of

weird but we don't want to get too crazy

and then the screen mat

we're going to go ahead and click that open

and we can click the black

and we can clip the white

and you can see it just becomes a crunchy nasty edge

so as these two come closer to each other as

black gets closer to why these two bars

two little knobs get closer

you're crushing the values

you're basically saying anything

of a value of 2.95 and the RGB or higher is being

turned to pure black

and with the white

anything lower than 5.95 is going to be turned into

white and it just crushes the value

you lose you win the battle but you lose the war

and you don't have all those fine details

I'm going to be very careful with this and maybe

take the clip black and just inch it up just

ever so slightly

now there are other tools in here which are used

here and there

like screen softness

you can see it just softens the edge a little bit

overboard and you can soften that up if you want

if you're getting sort of stair stepped edges

and there's d spot black which just kind of

kind of does an erosion

you can see you're getting these very

strange shapes here

again heavy tampering is

something that you don't really want to do too much

in this case we're just dealing with

actually getting the cut out mat

I'm not worried about destroying the image here

so with that said we have this

piece of key light that looks good

this portion here actually looks very good

now what you would usually do with this is do a region

per region basis when you're doing with key light

and again it's good because it's on a lockdown camera

so I'm going to take this key light paste it

put in my source

and I'm going to go ahead and

come in here

hold down shift Ctrl and Alt resample my actual

color and I'll go up here by the hair up here

so this is

I'll go ahead and label this call this top head

I'll take this key light go into my node and label this

right side

which would be camera right where we're facing

and I'm going to go ahead and

paste another one of these babies

come in here and again choose my color

again I'm going to get close to the edge here

and see if we choose

see it's very

going to be very careful here

there we go

so this would be more of the top left

so go ahead and call that top left

there we go

and last but not least

maybe we should hit up this corner at the bottom

so I'm gonna go ahead and over here

put the viewer in here again change the information

I'm gonna choose

and get this area here

look at all the detail coming back and then I kind of

punch around so this would be the

bottom

left

okay

so let's start to combo these with a key mix or

so here is a key mix

and what we're going to do

with this is I'm going to go ahead and put this to B

and a is what

we're going to keep or

in the mask

so a is what's going to be revealed in the mask

I'm going to go ahead and hit the letter

O to make a roto node

and this is the top of the head right

so I'm going to go ahead and take this roto node

and let's go ahead

oh you know what

I had the gamma on while I was doing all those chocks

let me go ahead and double check my results here

okay so that's the top head

that's the right

let's go ahead

and maybe refine that a little bit

another thing we haven't done is actually denoise

our plate which probably be a good idea

but I'm not going to do that

just for the sake of this demonstration

and so we have this right side

and then we got this top of the head right

so it looks like this area so I'm going to go ahead

and do my best to grab this area here

going to go ahead and hit the letter B

and add a slight blur to this roto

we should be a blur on all your rotos

so a is basically being added to B

so anywhere else is the B input anywhere in this roto

will be whatever is an a

so if we put those together

you can kind of see the difference here

in this case I can go ahead and come in here and

maybe extend this out here

right there so you can see the blur

we don't have a blur there the transition can be harsh

so if I go ahead and put this blur down and nothing

you can see you got that harsh edge there

so I'm doing this kind of quickly by the way

just so you're aware

so on top of that your daisy chaining here

so you take the input of B

and now we're going to add in this here a

and

let me just do one last adjustment here to this roto

but it's a region per region basis right

so go ahead and get let's go

out that far

there we go what the heck

we'll crush some of these values a little bit later

if we need to

all right so then again here once again

we'll take this key light

we'll add another roto mask so hit 0

copy and paste this blur

plug that in plug this in

and this is of course the top left

so that's this little segment right here

so I'll go ahead and throw that in

there we go and it looks like this

key could probably use a little bit work

I'm gonna put my viewer to it

and just come in here

and kind of get the best result I can

but still maintain those hair follicles

gonna be a little bit tricky

see the closer I get

we're going to lose some of this data regardless

okay

so that being added on you can see there

I'll go ahead and just extend this out

again I'm just

this is probably not as optimized as you would imagine

okay and then we have the bottom left

right which is this area

so again I'm going to take another key mix

paste it B Input a input

o for roto B for blur or just copy and paste this blur

plug it in mask it

and this roto I'm gonna throw down to this area here

there we go

so it looks like it only got a hold of this area right

here and I can keep going with this right so I can say

okay this area right here

I'm probably have to do a separate key for I'm just

being very careful to do very light keys on all of this

I'll just make another one and this will be

middle left

so I'll do middle left

and we put that

in and we're keying based on the luminance change

chrominence change for each individual area

so I'm going to just hit this key

hit shift control and alt

click the little problem child area that I want to get

get as close as I can

before it starts to get goofy on me

making sure I keep as much hair detail as I can

again copy paste you probably wouldn't use this many

you know

key lights sometimes you would obviously

and this is where IVK Gizmo actually

does a lot of this stuff for you in autopilot

so I'm gonna go ahead and copy this here

plug it in and let's go ahead and take a look at our

last viewer I look at it here

and then I'll just add in this area right here

so I'm just kind of adding in

little areas here as you can see

and again I'll just kind of

bring this to the best I can

obviously this will have to be animated

if it needs to be animated obviously

because the camera is

not moving you probably could leave these static

but if the camera had to pan or something

you'd have to animate it

so in general I could come in here and create

a merge node

and we'll go ahead and create a mask

so again I'm going to hit 0 for roto

and I'm just going to come in here

and mask around and make a

garbage mask around our character

as best we can

and we're going to have better

robust ways of doing this later

by the way and again I'll just copy paste this blur

B input a and we are going to set this to mask

so there we go

we got rid of all the gunk on the outside

at this point we can hit the grade node

and come in here and maybe crush

the values a little bit here

we can come over here and play with say

play with the multiply

again you want to set this to alpha by the way

so make sure this grade node is set to alpha

and I can just come in here and just start playing

put my viewer to it

playing with certain options here

you can see I can play with the gamma

which will kind of eat into my

thing here a little bit

I could also come over here to my blacks

start to crush the values just a hair

and then of course you got

you can try multiply

actually it's not going to do any good

unless you have a white clamp

so again just a little bit of detail

you can see if I do a little too much

I'm going to start through

all these fine here to details

but sometimes there is a compromise in that

so now that we have an actual alpha here

I'm going to go ahead and use a copy node

like this

and we're going to go ahead and

bring in the actual footage itself

so I'm going to go ahead and take this

and put this as the

coming RGB information and then the a is going to be

the actual oops I'm sorry

yeah that's right

a is the alpha information and B is the RGB information

and we're basically reformatting what is RGB

and what is a

so if I go ahead and

plug this through to the original image

like that and we go ahead and hold down Ctrl

make a couple dot nodes

to kind of come around to the opposite side here

there we go

so now you can see if I take a look

here's the original footage

hit a here's my alpha

and I could pre malt this so type in make a pre malt

so I multiply the alpha by the actual RGB

so it cuts it out and there you go

now just by looking at this you can kind of go and say

wow

this could use some

you know coming to grading here and crush the

you know this area but we have

so much of this green here

in the actual object and if we were to say put this

on a background if I were to go to my constant here

and let's choose a color here

choose something like

oh I don't know

something brownish like that

and if I would emerge this B for background a for a top

you would see

that we got a green Halo around the character

now the key light

is actually good on its own as a what's called a

d spiller and usually within keys we have

the area that we key out

and we're not worried about the red green

blue information

and then we have the area over here which would be

dealing with d spill

which is getting rid of the green out of the

reflections because a green screen behind this actress

is not only going to cast green on her face

around the edges of her

around her hair

it's just going to pollute it because it's it's light

it works again

it bounces around like four times and just you know

white areas absorb

white areas reflect and black areas

absorb so you're not going to see a lot of green in her

black shirt

but you will see it probably in her face a little bit

so key light on itself actually works as a good

d spiller so I'm going to come over here

plug in my source and I'm going to set my

screen color on this 1 to 1 for green

and voila we have taken out the green spill now

usually I come in here with the alpha bias of the red

because her face is red

and I'll bring this up to 6

okay you can see as I do that

there's more green being taken out her face

and also her hair

see the difference

see that just by bringing this up one

you can put this to maybe point five

five if you want

you don't want her turning into a

strawberry or a blueberry

which happens is you

kind of fiddle with this stuff a little too much

you can see she's starting to turn

into a blueberry if I go two nuts

so having a alpha bias at point six

I find is a good kind of balance

again if you need to push it

you'd still see there

maybe some green tinge in her skin

and that's something you get through

using maybe a Hugh correct

but we're going to get into that later lesson

so this would be the redefined RGB

okay so we're going to go ahead and plug that in

notice that the background information here

is unbelievably

actually

ridiculously dark right

so we've lost illuminance because we've basically

taken the green channel out

so one of the things we can do with that

is actually come in here and use a merge node

and we're going to extract

by clicking here for a B

right here and we're going to extract

minus operation

so hit minus the green information

this is the green information that we tore

out of the scene

okay so you can see there's a lot of it in

around her face here

in her teeth because her teeth are reflective

and along here and here you can see the shirt isn't

doing that because black absorbs

a lot of the light coming and bouncing around

so with that now I can go ahead and hit m for merge

I'm going to hit sat for saturation

I'm going to come over here take the saturation

bring that down to nothing

so now it's just black and white information

but it is luminance information that we lost

and we're going to reintroduce that

by putting a merge node from B to a

and we're going to set this merge node to plus

now we have re added the missing

luminance information but yet she is not green

so there is our final

commonly called the d spill or the red

green blue information

and this is our alpha information

we merge that

together with a copy node and now only merge this

together we have a nice looking background now

I don't want to jump any further than this

because I

obviously want to get into the other tools such as the

gizmo and the primat

but a quick fix for the fact that this hair is gray

because the luminance values are different

and also the color is different

is you can kind of cheat this by going back to say your

key light

and adjusting the red color influence

so usually I put this to point 01

on the d spill

and as I start to increase this

go back to the actual image here

and just see what we're doing

you can see as I do this

I start to reintroduce the little red

so that it's actually changing to match her hair color

see that

I'll go to the plus sign just so I can see

everything together here

but you can see the difference here you can see that

now again I can really push this

if I want to

by dragging this pretty high

and this might start to change her skin tone

but this background image is matching to her hair

as you can see

so again there's a lot of things you can do

you can also come in here and bring down the

intensity of the mix here

but I just want to show you by making

some slight alterations

of the color information

I can go over here to this merge node

now it's matching up a lot better as you can see

we still have

color differentiation here between what is

the backplate and what is not

because the information of the

gradient of the alpha is still showing the backplate

what's behind her

which is

all determined by how we actually did our d spill

so you can see we've matched her up pretty good

and I just go ahead and scrub through

obviously in this circumstance

you always want to put your

viewer to the last merge node and put your

second viewer to

your original plate

you always do this

you always always go back to your original plate

you want to go back and forth

look to see what you lost

and you can see we lost a ton of information here

so you can see here we've got all of this

information here that's been lost

oh my goodness how do we get that back well

again it depends on the key that you're using

one last trick I Learned from my good friend

working in the studio

was

where you actually color correct the background plate

okay so this right here

let's go ahead and take a look at our background plate

here it is right

it's just this stupid constant right

what you can do is actually put a grade note in on this

and what you can do with this is

we'll go ahead and take a look at her here real quick

I'm gonna hit R

G and B and we can see the

green channel

is where we get the highest amount of contrast right

so I'm gonna do an old type of key which is called

just a regular key

so these are used a lot in kind of pulling out

luminance based keys as well as ground shadows

so I'm going to go ahead and put that

into the original plate

and what it does is if I put this from

you know we're not going to deal with luminance here

but I'm going to go ahead and put this to

based on green key here

it basically takes the green channel

okay and floods it in to the alpha

so if I go ahead and take a look

I hit a for alpha you can see what we have here

so I'm going to go ahead and

crush the values a little bit

in here and this is basically a gradient

of the values from 0 to 1

there we go

now we also got to invert this I'm going to invert it

and let's see if we can

play with this other bar

you pull out this other bar here

and just kind of clipping that

you can see it's going to be very hard to extract this

all these fine wispies

but we're going to grab whatever we can

and the white is the area that's going to color correct

so I'm going to go ahead and make a dot node here

so we can extend this

bring this down here

and bring this baby all the way down here

there we go

and I'm going to go ahead and plug this in

before I do that I'm going to go ahead and add a mask

so I'm going to merge this

because I don't want to color correct everything

so this will be the incoming image

and then the a

will be a mask or roto that I will create

that roto will be only around the hair areas

in this case I can only isolate this area for now

I'll have to do individual keys that are

just like we did with key light

based on the luminance of these different areas

but I'm just going to use this area for an example

I'm also going to grab one of my old blurs here and

piece that in there we go

that way we just have and I'll put this to mask

so now you can see we just have this area cut out

and I will use this

as the mask for the grade for the background

so now you can see if I take a look

and I'll take the grade

and start to multiply this down

look at all the hair detail that has come back

in that little area there

so now I'm going to go back to my merges

my original and my end of the line front of the line

and you can see

we've retained all this information

based on a hack where we've color

graded the background

now we've color graded it

unfortunately in a color that is black

so you can come into this multiply here

click on the four

and play with

if you want to make it more like the color over here

which might be a little bit more red

so you can kind of play with that a little bit

so you can go ahead and see the difference

between that

you can see a huge world difference that this can do

to retain values that you couldn't get out of your

key due to

quite the variation of a green behind the actress

so a lot of stuff I'm throwing at you

okay so the next thing I want to show you is the primat

so the primat

let's go ahead and drag this baby over here

and we'll bring our actress here

primats are usually used for creating cores

which is very important

to understand

that despite all of this keying that we did

if I go ahead and take a look at her actress here

you can see if I pulled it down she is

slamming the gamma she is still transparent here

so if I were to sample this area here

you can see the actual value is point 998

okay so that is technically unacceptable in regards to

an alpha input that you can play with here

it's 1.05% or

lower is what is allowed in regards to transparency

for the most part especially out here in this area here

kind of sample here

you can see the value is like point 033

that's that's fine even though

we do see noise here it kind of translates itself into

not being seen in the plate itself

but if you get values in here out in the black area

that are above point 05

then you got a problem

so that's sort of like the middle ground

even though you see gunk up here

like let's sample this

so the average is point 02 right

so that is actually acceptable

that will not probably be seen

in the final output

and we can test it just by looking at it right

if you see sort of noise up there in your shot

then you know you got to deal with it

but in general it is what it is

so again let's go back to our primat

primats are just

very destructive in the sense that it's almost like

creating a key with a permanent marker

if you make one mistake it's hard to go back

and I just find that the undo button is a bit buggy

so I'm going to go over here and plug in the foreground

and take a look at it

now this is what I call a three dimensional keyer

what does that mean

well if I come over here to this

nice little color wheel I've put in the scene for you

put my

viewer to the Roto here and double click my Roto node

you'll see

the key light was using a variation of luminance

and chrominence

to pick out an area

but the great thing about

primat is a three dimensional key

it almost like works like a wormhole

if you want to talk physics

where it can jump to different areas

that are not connected

usually as you increase the area that you want a key

it kind of grabs everything in the middle

as you extend it out

but here's a way where I can actually grab

and again this is the gradients of the tolerance

of what it actually picks up

actually

grabs stuff that's outside of that sort of diamond

so to speak

so it's really cool it's a three dimensional key

so let's go to the primat here

I'll just double click it

and again you have this option your operation

this stuff is very

dummy proof

you can go here to smart select background color

and just like we did with the key light

you're going to come over here and click a color

and boom we've got a starting point

so let's go ahead and hit a for alpha

let's go ahead and sample an area there

and now all I do is go to clean background and

clean foreground

so I just go to clean background noise

anything that should be transparent

I'm just going to hold down shift and control

and gobble it up

as I do this and you can do it by grabbing a whole area

but it actually makes you

it's starting to make your edge a lot crunchier

so I find that just

clicking once in a while instead of

clicking and dragging like this

can kind of save your key

so with that I'll go back to my clean foreground noise

and bring down my slam my gamma here

and I can come in here and grab the

center area is like crazy

now you can see what's going on here

it's starting to harden up my mat really badly

okay and that's just the reality

of this whole thing

click on viewer here

and you can see

the actual three dimensional representation

of what is being keyed out in this in the red

green and blue channels here

in the three dimensional space if you wish

it's nice eye candy

but it really doesn't help you very much

so now you can see

everything looks relatively you know blaze

if you were to merge this on a background

the edges would be a little bit harsh

so if you were to compare the

edges of what we created with the primat

versus what we have in regards to

what we did with the key light

you can see the amount of detail that's been lost

the good thing about the key light

or the primat I should say is it works as a great tool

for actually creating cores because it still maintains

the edges but allows for hardened centers

so you usually would come in here

and again clean this up a little bit more

you probably grade it a little bit

so you can come in here and grade this oops

do another grade but a grade

and again you'd set this to the alpha channel

and you come in here and crush the blacks a little bit

as you can see as I crush the black starts

eating into the mat

crush the whites

ever so slightly

and now you have you can slay on the game

you can see we have a pretty solid

center there but this actually has axe as a core

that if we were to hit m for merge

we could actually after this

merge this on top so I'm going to merge that on top of

the footage here

so I'll just bring this over here really quick

so here is our you know key light which has holes in it

and if I take in comparison between the two

you can see

this is a little bit skinnier

now this could be troublesome because these areas

you know

obviously these areas of the semi transparent areas

and this is fine

in general

you might also want to come in here and play with the

gamma as you can see it kind of

eats in a little bit more too

you can do that

you could also use a lookup

tool which I'm going to go over later

this and I'll go ahead and set this to

let's put it as

well let's just plus it

now I want to show you what happens when you

plus something

you get values that are

above

value of one

so I'm going to go ahead and

put in a quick clamp node here

like this

and now those values are no longer that they're

limited between the normalized values of 0 to 1

or you can go ahead

put this to say screen

which is usually a nicer way of working

and you can see the values are

still normalized

so screen is actually preferred

but you see

what it did is it filled in these areas here

so now if we kind of look at our

again you can see we have a nice core

so it fills in the center

so that's why Primat is a really good tool to use

through this whole process

and I'm just going to organize this just a tad

so you guys can

have it look you know take a look at this

I do have the start end finish for all these files

so you're not like

what did you do

you know I could just go ahead and show you

so let's go ahead and take a look at the final result

and there she is looking all joyful

we still have some green in her face

these are the subtleties you got to keep

an eye out for

as you can see here

and we'll get into how

we're going to be dealing with that a little bit later

but as of right now that's just a quick example

now the final

key I'm going to go ahead and show you guys

is the IBK Gizmo IBK Color

this is the most popular in the whole process of

keying and so forth

so sometimes it's hard to explain

what in the world this does

so here is our actress

I'm going to go ahead and add a d noise while I'm here

so let's go ahead and add a d noise

put the d noise in the source in

sample up my area

and now we have taken out the noise in the shot

so go ahead and take a look

before after there noise is gone

we blurred the image a little bit

which we can sharpen her later on

which if you sharpen too much you'll get black

edges around heavy contrast areas and it's not good

so again any time you tamper with the image

you're tampering in God's domain

and you're fiddling around

and it

can degrade the image and make it more synthetic

so we have the IBK color and the IBK gizmo

so what does this do

well I'm going to show you using a rhodo paint node

what the heck this does

so what it does is it takes the original plate

and it this is going to sound

really goofy when I kind of describe it

I'm going to take a smear brush here

and what it does is it basically does this

it's basically taking the sample color

you know

we have different lumens values all around her head

because it's darker over here

as it is lighter over here

basically what's doing is it's just doing this

it's choosing an edge and then eroding it

in from that edge

as you can see here

so imagine go ahead and make this crazy big

it's doing this

so it's moving the sample color here which is

most likely the color that should be sampled

and it moves it into

the character's center

and what we're basically doing is a process as if

we got rid of her completely okay

so I can keep doing this till the sun goes down here

right

so if you were to take a look the difference

it was almost as if

it's a fake back plate

or it should say clean plate

and clean plate usually if you have a shot

if you're on the stage and you're

VFX supervising and the shot is a lock off shot

meaning it's a tripod shot lockdown

tell your

DP to shoot some footage with the actor out of the way

and that footage can be used as a clean plate

but this creates the artificial clean plate

which is if we told the actress

get the heck out of the way

and we shot some footage

so you can see it looks as if she disappeared

I could keep doing this until she disappears

as if she actually is

out of the shot all it's doing is smearing in

the pixel values around here

and then it's using a difference

key or the difference between

the backplate

and the original and taking the character out

so what I like to call it a difference key

okay so with that said let's go ahead and create that

so we don't use obviously a

smear brush we use the IBK

color which we're going to plug into our d noise

this thing by default is always set to blue

I don't know why they just set it to green because

most people use green and secondary blue

but it's set to green

and I think that's because the old software

used to use blue screen more than

used green screen

switching over from film to digital or whatever

so you can see

the image you get is this very odd image here

where she is

basically

has an outline

if hit a for alpha it's actually choosing an alpha

so this is

the best that it can do it's basically keying out

basic green here

and what you have to decide here is the size

you can see here by default 10 is usually fine

and then you have darks and lights

so this is basically in the same way we were doing

keying with key light

defining out the tolerance of

brightness versus contrast

I'm gonna put this to point zero one

and I'm gonna start dialing up this one

until it kind of

choose up everything we want to get

even those hair wisps

if we can now if you do this

it starts to

explode off to the side of the screen here

as you can see it's like oh crap

that's not good

so I want to kind of wait until it explodes and stop

and now I'm going to go to the lights

and put a value in there

on the greens

and I'm just going to start fiddling with this until

I can get something

there we go now the next step is in a row that just

basically a row just

erodes in or dilates out the actual alpha edge

so now I'm trying to get

all these hair details as best as I possibly can

okay so

let's go ahead and fill it with this a little bit

you can see if I pull it I can overcrank it

678 scenes with heavy hair

lots of hair and not hard edges are a little bit tricky

you might have to introduce a mask

which I'll talk about

I'm going to demo later on

where you actually introduce more to the roto

by adding in more alpha

via Roto node but the hairs are tricky

I would actually come in here

and roto this area in and add it to the alpha mask

because it's no good

so you can see what it's going to do

it's going to take the pixels on this

where this line is at

smear them in

so

you can see the patch black is going to do that

so I'm going to go ahead and drag that in

and I can overcrank this to ridiculous

now I'm going to talk about the daisy chain

version of this later on

but I basically brought this to a patch 20

so let's take a look at the original image

let's take a look at the shot

it's almost like we told the actress

get your butt off the stage

and there we go

now

we're going to have problems over here with this hair

okay

because it's going to use the difference between this

and this and do the key

okay

so here's the IBK gizmo

I'm going to plug in my clean plate which is this

or if on set I told the cameraman

get the actors out of the way and film

and he gave me some B roll footage shot

temporarily at a different time

I plug this in here because it was a lock off shot

and now

I'm going to go ahead and put this in my foreground

and take a look

I hit a for alpha

now again

by default the IBK gizmo is set to blue screen

you have to set this to green screen

annoying but look at this

this is like everything we did here

but done

all at once with this node because instead of sampling

this area this area this area

this area this area this area

this is basically

using a difference mat to get all the details for us

all one so

let's take a look at the difference of what we created

here versus here

you can see

the difference

look at how much detail is in the IBK

I've talked to many of my

students that are big time VFX guys now

and you know they are

still this is the best key

so it saves time and why is this good well I did

a commercial with Sam Jackson

the Capital one commercials I used to do and

you guys can look them up if you want Chasm

Snow globe also tiles

they're all on YouTube and so forth but

Sam Jackson is moving through a scene and he is

basically he's moving through a green screen stage

and the luminance is changing behind the actor so this

moving shot is not good for key light

whereas a moving shot

is great for the ever changing

background of the character in say using the IBK gizmo

so with that said

you can see obviously we have some noise patterns here

if I sample it the values are at point zero zero four

right those are acceptable values

actually we are not even though we can see the noise

those are still acceptable values to be used

and overlaid even though

people

usually will come in here and they'll add a grade node

they'll set this to alpha

and then they'll start

coming in here and crushing the blacks until

you know lose all the detail

but look at all the hair detail

you're losing with that

see that we've won the battle but we've lost the war

so again

I'm going to maybe do just a little bit of clean up

and even bringing the y point not as far as

like 990 because we still have holes

in our character

as you can see

this doesn't fill in the holes in the character

too much in this case actually it does does pretty good

again I might bring this

I don't want to bring this too crazy

maybe.97 or something

did a pretty amazing job as you can see now

we would probably come in here and do another

let's create a merge node

and we're going to create a 0 feroto

and let's just make a quick garbage mask while we're

here so just go ahead throw it like that on

steal one of those blurs over here

paste that baby on

and set this to mask

there we go and again just blue this edge if I want

there we go so

pretty cool and again it gives it a beautiful

absolutely beautiful result

from which if we were to swap this out right

so go ahead and swap out the a here for this input

really quick

so basically doing all the work that key light did

except this time we're going to see the result

using

the actual

IBK color in gizmo

and look at that

all those here details

are there

now hair can be

a bit of a pain the rear end with the IBK gizmo

because

to collect the hair can be tricky

so I usually introduce

some manually animated rotos to cover up

all the hair when it comes to this area right here

so even though

this is the quick way of doing it

I'm going to show you the daisy chain version

which works even more effectively

in the whole process so that in a nutshell

is all the keys

again you want to denoise it

you can also use this screen clean tool

but again

you got to

don't get too crazy because you'll start to lose

details and the highlights

or as far as the motion blurs

and the actual wispy hairs

but you can see how just these tools alone

now this is still not gonna cut it

we're gonna get into crazier even more

powerful keyers and d spills to really make

everyone kind of blend in

we gotta talk about graining regraining image

I'm taking you guys all the way

to the professional end

so that if you were to show up at say

the mill or

any one of these studios you would be ready

to do keying at the very least

that's just one element of compositing obviously