All language subtitles for Fundamentals_03_Exposure_02

Hello and welcome to this next lesson where we
continue to look at exposure camera

values and how to set up and actually pleasing
relationship for our image.

So you remember last time we set this up and
one thing

that I would really like to illustrate before we
actually

like,

jump into things is

Remember when I said that we can make things
look

the same even though we have different values.

So to quickly illustrate I'm going to go out here
and we can see that our exposure now adjusts.

And so if we gonna turn on Min and Max TV,

You may have watched some YouTube tutorials
or videos.

We're basically someone said like you know I
want full control I'm going to set this to 1 and 1.

All right and now the exposure is locked and it
kind of looks pretty bad obviously.

So now what I can do is I can go in here and I
can set my default value to 1 and we have this,

right?

And this base.

Basically looks exactly the same as what we had
before.

So even though my intensity is now one and
I would need to recapture

my Skylight as well to basically get the same
intensity of the lighting,

but we're just looking at the background right
now.

So now my intensity is set to one.

And my exposure is locked at 1.

But this thing is,

basically,

that is not a realistic exposure value for a setting
like this.

So this would be more like an EV value that
you would use for a for a nighttime.

But we can like make it work and this is like one
of the

things that like takes a little time to get used to,

but it illustrates how the values are like,

really only depending on the relationship that
they have with one another.

And one of the most important things here
again, is that in real life,

the differences between the values is very large,

so it makes sense to actually do that when when
we do our lighting as well.

So we actually do get like these proper
differences between the different settings and

like interior versus exterior. We get the right
contrast between Sun and Shadow,

so that is very important. So if I just like change
this again,

And put this back to I'm doing this off screen
right now,

but I'm just resetting the value and we just wait
for the exposure to kick in.

And now this not like, how would, you know,
what is this number now?

Because it can go between minus 10 and 20 and
the easiest way to find out what number

we are actually sort of locked in right now is to
This and this looks like we are.

On

probably.

Like 11 or something like that?

Yeah,

so if I would like take this and do like,

yeah,

like we're more here where to where the blue one
is so we would need to do like

Yeah,

sort of like this.

And you can see now we're locked in and it is
the same as if we would set this to 11,

and just like reduce our Sky intensity.

And that is what I meant with. These values are
sort of arbitrary.

However, this will become a lot more important.

So now the question is,

how do we actually get our son in here and have
it work properly?

First thing that I also want to do quickly is I just
wanna,

Look at my.

Room here again.

And I wanna

Rotate my sky.

turn off the exposure,

debug view because otherwise I cannot really
use the gizmos

and I kind of want that the Sun

comes from over here.

I like this, maybe.

all right,

so

how do we actually get this relationship?

So now there's a few different ways of doing it

and I'm going to walk you through these quickly.

So if I take my directional light,

which is off going to turn it on and you can see
nothing has happened.

And the reason for that is, is because right now,

my directional light is actually set to 10 lakhs
and 10 Lux is like

literally invisible because of our exposure being
like 12.

So we need to crank this quite a lot to make it
visible.

So let's first of all,

go into our Skylight quickly and just make sure
that we have the

latest and greatest in our settings. Because see
we change this.

So like the shadow didn't match at all.

Because now we're going to have the light
coming from here.

So now this looks more. Correct.

And then we go into our directional light.

And now how do we know what? Value to
choose?

We don't really and also like if you do this like
you slide it like a hundred and fifty lakhs.

That is completely, not physical. So what are we
going to do?

Well, we overwrite manually and we just try stuff
so we can do like maybe 5,000. We like, ooh,

nice.

Here we go.

so now something really interesting like it
actually feels like

this is not really bright enough if we like look at
the surroundings, for example.

So one interesting thing here is that, so this
building back here,

it doesn't really look white to me, it looks more
gray.

And this is probably like reflecting the sunlight.
So the actual color is most likely,

something like what we see over here and this
sphere,

this Cube,

excuse me,

this Cube has 50% gray value.

So this is like perfectly medium Gray.

So now first let's see.

That's actually if we look here is the sun,

here's the shadow so this looks lined up pretty
well so that's good.

So again is this the correct value or is

This took a ride. Correct value.

We don't really know.

However, what we do know is that we do need
some sort of contrast,

so having a value that is too low,

as probably not really gonna cut it,

it's probably not going to be super good and we
can see here, we have something happening.

Also, we have like some nice GI that we started
getting.

So this seems kind of cool.

However, we're still also looked at 12 and 12 is
like a pretty good exterior exposure.

So now there's a bunch of really interesting
things

that we can kind of use to like figure this out.

The first thing is,

we can use our gut feeling and we can say like
how strong do I want this highlight to be.

so, because if I go like 35,000 for example,

This starts hitting really good.

And if I look here, that is probably white. So, of
course,

we don't want this middle gray to look like the
white here, which is like also hit by the Sun.

So what we're doing right now is we're basically
just looking at what

we have and we're trying to find reference points
in our Sky HDR,

which does have some really good values.

And honestly, like looking at this,

To me and that is like my gut feeling again. And
also my experience this looks too bright.

Like I don't think that the stuff back there which
is kind of like grayish.

Like I don't think it blows out that much so
maybe.

85,000.

So,

this is something where we can again,

decide based on gut feeling, and we can say like,
hey,

I kind of like this. I think this is like a good
balance.

And again, looks like this inside, I think, like the
bouncer, we're getting. It's kind of nice Works.

We're also starting to get some more filled
bounce here.

This is one of the things why Lumen is so great.

Because in the past we just had to like test
vague this all the time

and we did not really know. Like was it good?
Was it bad?

We don't we don't know until we bake it now we
pretty

much know right away which is a great thing.

So in any case.

So this is one way of doing it.

However, if we remember what I said before,

there's a lot of

Ways to do this that are actually derived from
from photography that help us.

And one interesting thing

like people doing photography,

they sometimes use something which is called
like a light meter.

And with a light meter,

they actually measure the Luminosity of
something that they want to take a picture

off and then they get values. And these values,
tell them how to set their camera,

and how to expose the

And there's 11 very, very simple rule that I really
like using for me to like,

get me the balance that I did.

I want is

it's basically like midday.

The Sunny Side of an object is for stops
brighter,

then the shadow side.

In the afternoon. It's like three stops.

In the evening,

it's two stops and at some point the sun is like
like like very very dim and

only acts like a tiny bit of color but not much
sunlight anymore, right?

So this is actually something that we can use
here for our setup.

So what we can do is we can go back into
visualize,

we can go into our HDR value and now we just
basically look at the shadow

side here and now we can see it measures an EV
of 10.12 or 13.

So that means that if we say, like, okay, so this is
like a medium afternoon.

It might be that the sun is like 3 to 3.5 stops
Brighter Than This,

which means we should have around like 13 13,
.5 over here.

So let's measure what do we have?

We actually have 13 .5 which now this is the
thing.

Like right I told you I going to go by my gut
feeling, but since I did this so much,

I kind of have a feeling For how these things
should look like. So I kinda get it more right.

Like, just because I am that experience and this
is like the values is lining.

Perfectly.

And now what you can do is you can say like
well I yeah cool story but I

want to artistically tweak this and let's just say
we go with like 15,000.

So now we're on twelve point nine,

which is still like now it's like proper like three
stops more or less and

if I go back to 25,000 it's 3.5 stops this is
completely up to you.

However this is what like this contrast that we
can see here.

Actually, let's choose the median between these
two and go with 20,000.

So

this is what,

like photographer found to be the perfect ratio of
Shadow and

light for a setting like this and that is one way to
do it, right?

So if we would like now and this is the beauty of
this,

and this is why I love this approach so much.

Like, if I say, okay,

let's do something completely different. Okay,

let's

Let me just open the sky here, quickly on the
side.

Let's say we're going to do this thing.

So here is a problem. If we look at the sky,

the sun is actually not really there anymore.

But we'll we'll just assume we'll just assume for
the sake of argument

that the sun would be right here at the Horizon,
okay?

So the first thing is like okay, this was just about
the relationship and not the actual values.

So what do we have to do?

we going to go in here into our page here and
something has just messed with the colors,

okay,

so if we go

Down here.

This is like no typical photographic seen at
Sunset. Let's say 25 Candela per square meter.

That is actually really really low.

Because that's not like 2,500 or like whatever
that's like 25.

All right.

So let's just play this through and I'll show you
how easy it is to actually make sense of this.

So the first thing that I'm going to do,

I'm going to check this Shader and these are all
known as the wrong shade

or sorry this one and we're going to turn this
into like a parameter

Sky

texture.

Going to save this.

And in here,

we just gonna create a material instance,

call it Sky sunset.

And now obviously the good thing, if we just
like, open this weekend,

just like override our texture here.

No, need to mess with anything that we built
before.

What is this saying?

Okay, great. So this is a perfect example.

So here you can see that for this texture, it says
texture,

right?

And for this texture it says texture Cube.

Now why is this happening?

So per default, when you download a sky like
this,

it usually comes as an HDR file,

and when you import an HDR file into unreal, it
actually gets imported as a cube map.

So it's basically like a three-dimensional texture.
So,

to

And if you have a Shader like this and all the
texture, sample doesn't take a cube map.

So when you put a cube map into Shader, like
this,

you actually need like some math going into the
UVS so

you can project it properly and also be able to
rotate it.

I personally don't like that workflow. A lot
because it's just like a little bit cumbersome.

So, what I usually do is I re-save the texture.

As an e XR and an e, XR is still internally, an
HDR file, but I could just drop it in.

And then when I rotate the Skydome geometry,

detects churches rotates with it which does not
happen when you use a cube map.

So what we can actually do now is,

let's see.

Do I have

Hey, version here.

That is already changed

and I don't,

which is absolutely fine.

So,

what I'm going to do is I'm just gonna open this

It will not tell me like a Photoshop.

Okay, let's do this.

Just drag this in.

So now the only thing that we're going to do
actually is we just going to go and save a copy,

we're in the same folder. That's fine,

not going to call a copy.

I'm actually just going to call it e XR.

And here,

which is change this to openexr and again, it
stays as as an HDR file internally,

no compression you're going to hit, okay.

So now that this is safe,

just going to drag this in here.

And I will explain why this one is actually still
useful the the cube map.

So I'm going to open this and you can see it has
the VT that stands for virtual texture.

We don't want this to be a virtual texture at all.

So we're just going to search here in the texture
settings and it's just like turn this off.

And it does a little magic and then we're good

save this.

And then I'm going to browse for this. So it's
selected.

I go back to my Shader and I'm just This.

Now the error is gone.

All right, beautiful.

It is still doing something though.

Okay, now, we're back working.

Cool.

Zou with that said,

I'm going to apply this Shader now to my editor
spear,

I can see kind of looks the same.

We have all these ranges so but this is quite
clearly wrong now because

This is way too bright and we don't have this
exposure for such a low setting

because like we can see that there's lights in the
inside of the houses, right?

But these local lights, they actually have a very
low intensity.

They might be using like 1500 to 2000 Lumen
and if I would put a light in here with that value,

you actually wouldn't be able to see it.

Because again because of the huge range that
these things have.

So I'm going to take like a point light here.

And I'm going to change the values down here.

You can change the unit's.

I'm going to use lumens because lumens is what
you can

find on the actual packaging of light bulbs that
you buy.

So you can basically say like oh cool I have this
light bulb in my living room and it has like

that intensity so you can then just feed in the
value here and you get the same thing.

So let's say we go with like 2000.

So did you did you see like I actually did get
something but like you know, not really like a lot.

So if I'm like,

go up here so we can like the light is clearly
doing something right.

But you can see

if I go out here.

This by no means.

Looks like what we can see over here with the lit
interiors and that again is because like right

now the sky is actually having the brightness of
a daytime sky and not of this Actual setting.

So I'm gonna actually keep this light in here,

so that's going to be interesting to see.

And now what I'm going to do is I'm going to
turn back on my HDR, visualization thingy.

And if we remember our sky,

like 25 Candela per square meter.

So now I can we get into this field of like artistic
Liberty to a certain degree, right?

So if if I like measure you can see like this is like
2100 there's like 4,000 even on the brighter

Cloud. There's probably a lot more here but we
can rarely see it and also super trick like Wendy.

Use are so bright in the image and you want to
measure them if you can't see

the numbers anymore because epic doesn't
have a dark outline for the text.

What you can cheat is you basically look at it
and was like, oh no, I can't read the number.

So, you just go into the exposure compensation,

and you basically just compensate it down,

and you see the value is still, what it actually
reads.

So it is the value that you measure is not
influenced by this at all,

but now at least you can read it again.

So that's my little little hot fix.

Or when I use this again now. So where do
we actually measure?

And what I decide for myself in this case is, you
know what,

I'm just just going to measure in the center of
the top of the sky dome and that is like, again,

artistic Liberty. Like there is no rule for this.
There is no.

But like if I consider this to be an average right
like where the sun is the sky is going to be the

brightest and opposite. To the Sun, is going to
be the I guess so, my brain just tells me like hey,

it seems logical to measure right, straight up
into the center.

So that's what we're going to do.

I'm going to open my instance here again.

And let me just slide this over.

Can I like doctors over here? Yep, that's better.

So

Now,

what we're going to do is we just gonna slide
this down until we can read like 25 and it's here.

So let's do

200. Okay so we're still at like 246 here,

so let's actually do 50.

Yeah, still too bright.

What was it 25?

So let's actually go with 15 Moon, our to dark.
Let's Go with 25.

Okay. We're 30. I think 30 is fine for now. We
don't have to match it like super. Exactly.

So now you can see that this is a completely
different story.

Lori than what we had before.

And now,

what we need to do is we need to adjust our
actual exposure to compensate for this

So what are we gonna do?

Well,

we gonna go into our post-process volume.

We ignore this.

And now we're going to set something that sort
of looks good for us and I'm going

to eyeball this, I'm going to say it's probably
going to be around seven.

And

yeah,

that's pretty good.

also, we can see that this looks completely
broken and that is because, of course,

we haven't recaptured, our Sky lighting,

So, we're just going to do that.

Now this is completely different, but also we
have our problem,

that it still looks wrong because of the sun
obviously.

So first thing for now, just going to like, turn off
this light here.

Because we want to make sure that the stuff that
we have is clean.

So like now also like our sun very very badly.

I think we can.

Let's rotate this guy a little bit so we can actually
like

maintain our sun rotation here even though it's
like,

let's do something like this.

Again,

I have to recapture because changed slightly.

Now,

our sunlight

Is completely off,

of course it is.

We have way too much brightness.

We are also not flat enough because like if
we have a scenario like this,

we would have some really,

you know, very long Shadows.

Even though again I know we don't have
shadows right now

but we just assumed that there would be a little
bit of Sun.

So one thing, if you click your son and your
gizmos weird,

that's probably it's because it's a local space.

So you can click this one up here and it Cycles
between local and world.

So we can just drag this out so you can see this
And

so what we need now is we actually need to like
rotate this to be a lot like more flat.

So that's the first thing that we going to do.

Now, I'm going to switch it actually back to local
because now you can see,

I get the axes a lot better.

I'm going to fix this a bit and now what we want
to do is like the kind of want to go.

Like this,

so it's not super accurate, but it is going to be
like a lot lower here.

With the song coming in like this.

And then what we also need to do is we need to
actually fix our colors and our intensities.

So the first thing I'm going to do is I'm going
to put this 20

I will turn on again,

my visualize.

Hdri adoption.

So here we have like three point six.

All right,

so if we say that,

we just go like, One-Stop writer. That would be
like 4.6.

And you can see we basically already have that
because the thing is we don't actually have a

son here and the brightness that comes from
this is basically

already the brightest spot here and we already
have this

Almost One Stop difference but we can see
there's a little bit left.

So here we have three point six here, we like 4.3,

so we can add 0.3 ish with our son.

So, let's do 10.

20.

All right.

So now you can see we added a tiny little bit of
Sun, so there's here, our shadow,

you can see it.

So I remember this number 20, lakhs,

and 20 Lux is actually pretty accurate for
something that is like, very late in the evening.

So I'm going to do two hundred so I can see it
more.

And now,

what I'm going to do is I'm actually going
to match the colors and one thing that

I really like to do and that I highly recommend to
any of you use temperature.

Because I don't go in and do like yeah, sunlight
is like this.

Don't do it unless you do something.

That is

A highly stylized or be,

it's something that is like,

I don't know, you know, like a weird planet or
something.

Where like for some reason the Sun is blue or
whatever or you have like a you want to

emphasize on like a swamp feeling for like an
isolated area and you can like maybe like,

you know,

none ship towards something greenish or
something.

So, of course, there is some artistic freedom.
But if we talk about like regular stuff,

don't ever touch this,

keep it.

On white.

Hit the color and you can see it already got a bit
warmer because per default, it's 6500.

Kelvin and 6500 Kelvin is the white Point
basically.

So

we're going to check this and since this is very
late in the day,

we can actually go down quite a bit.

We can go to like 1600 and you can see now this
kind of like matches the feel.

However it is way too strong,

so What we need to do again, as which is go
back here and we going to do 20.

And now you can see it does add a bit more
which is not perfectly

realistic but you can see the colors really look
nice.

And if we go back in here,

we can suddenly see that.

Okay,

this kind of seems more balanced

and then

if we go to our Point light here,

Actually, let's do like 1200. That is what they
usually are,

again.

I'm actually going to turn on use temperature
because most

of the interior lights work with temperatures as
well.

And a lot of the interior lights are actually very,
very warm.

That is something that most people don't really
know because, like, our eyes also,

adjust for things differently. But, especially when
you do like photography,

you'll notice that like a lot of the lights that we
have inside our houses, our Apartments,

they're actually very, very warm.

And They usually are between two thousand
seven hundred and three

thousand six hundred Kelvin so I'm gonna go
with 3000 right now.

Let's turn it on.

And I need to get rid of this.

So now you would say, like, okay, that's still not
like super bright, right?

And that is usually, like not what you, what you
like sort of get and that is correct. So,

let's just make it a bit brighter by having more
lights, which is also a, very common thing.

Because when stuff is dark,

we add more lights because that's what we also
do in our homes,

when it's dark.

So I'm just going to put this In.

And lately, we do we ignore like all the shadow
casting stuff and like all that for now.

So,

this is what we have here.

And now the fun thing is obviously that when
you look from the outside,

Let me turn this off.

We do have something that matches a lot better.
When we, when we look at this.

I think actually, these lights are even like warmer,
so that's like a difference,

but we can see that our Interiors are starting to
do something as well.

So now the thing is this kind of like still looks
very very dark and and that's correct.

And that is because right now the exposure that
we have is

something that is more pleasing for what we see
outside.

And again, what we need for this and this is
what games do is we need Dynamic exposure,

so if we just go in here

and we reduce this to maybe 5.5,

Now we're starting to get somewhere and, of
course,

we get this becoming brighter because that is
very, very natural to happen.

I'm just like getting really annoyed with these
really hard Shadows here.

That's not very beautiful, not very natural and
that sense.

But like for now that's okay.

We can, we can change that,

but it's also not necessarily super important for
what I'm trying to show right now.

So here you can see that.

Now we have

This setup and we could maybe even go to like
five.

So now this matches really well and if we look at
something so bright,

it will actually go back to something a little bit
different.

But again it will not actually go up to the 7
because the default Auto exposure.

Always tries to aim for a medium gray average of
the of the image.

so, if you would like to have this,

Look darker than it did when like, like it did when
I did this.

But you still want to be able to have the five here
for when you go into something.

There's two ways of doing that and we will look
at these ways in the next lesson.

So this is going to be it for this time.

Thank you so much for watching and see you in
the next lesson.