LIGHTING in Unity Video Lecture | Build a Game: Unity Tutorial (English) - Game Development

so recently came across this awesome
tutorial on lighting a simple scene in
unity and I thought I would do the same
using the new and improved progressive
light matter so in this video we'll
learn a bunch about lighting and use it
to put together this scene also make
sure to check out the guy who made the
original tutorial
LMH poli he has a bunch of really useful
videos this video is sponsored by Dennis
Pandita then this is an awesome udemy
instructor and has just launched a new
course the complete unity 3d game
development course throughout the series
you'll learn how to create six
completely different games this includes
pong six egg and farmville when you're
done you should have a solid
understanding of unity as well as
programming in c-sharp
you'll also learn how to create basic 3d
assets using blender so to get started
simply click the link in the description
and get a discount alright let's get
into the video so before we start
setting up lighting there are a few
things that we need to understand the
first one is global illumination we all
know that our eyes work by picking up
rays of light unless we are looking
directly into a light source these rays
of light bounce around between objects
before hitting our eyes every time the
light hits an object it gets modified
absorbed or is sent out in a new
direction depending on the properties of
the material on that object because of
how powerful modern computers are this
is something that we can now simulate
and the results can be incredibly
realistic in computer graphics we split
up this act of light bouncing around
into two categories direct and indirect
lighting direct lighting is when light
gets sent out from a light source
bounces once and then reaches the eye
here is an example of a scene with only
direct lighting enabled as you can see
objects not directly influenced by the
light are completely dark indirect
lighting is when light bounces off
multiple surfaces before hitting the eye
of course theoretically light will keep
bouncing until it gets fully absorbed
but we can often get away by only
calculating a few bounces after which
the remaining light waves will be so
weak that they don't have much influence
on the final image anyway now enlighten
is a solution for delivering real-time
global illumination this is great if you
have a lot of moving lights or objects
in your scene but often you want to
calculate lighting beforehand both to
get more detailed lighting but also to
save on
performance this is called baking when
you bake your lighting unity calculates
all the lighting values and turns them
into large textures that are then
overlaid on top of your objects while
you can use enlighten to beg your
lighting it's much preferred to use the
new progressive light mapper the
progressive light mapper is a path
tracing based light mapper which means
that it will realistically simulate
lighting bouncing around the scene it
does this by gradually sending out light
rays from the camera towards the light
sources this means that you can see the
result as it renders in the editor and
you can adjust light properties without
having to re render the entire scene so
with that explanation let's jump right
in to unity sir is the symbol seen in
unity I'm using completely default
settings here the only thing I've done
is gone ahead and import two 3d models
we have the room here which is just a
simple cubes where we can see through
the back faces of the walls and a monkey
it's cute right I've also taken my main
camera and positioned it so it looks
inside of the room now the first thing
that we want to do is set up a few light
sources by default every unity scene
comes with a directional light I will
simply go ahead and remove this that's
because I want this to be an indoor
scene so instead let's create our own
lights of course we could go right click
light and select one of the predefined
lights or we could simply create an
object with an emissive material and
that's what we're going to be doing here
so that's right click go 3d object and
let's select a plane that's also
disabled lighting in the scene view so
we can clearly see what's going on let's
set the scale of this plane to 0.2 by 1
by 0.2
let's also reset its position let's
rotate it by negative 90 on the Z here
it's not pointing out from the left wall
I'm gonna hold down control in order to
snap this plane it snap it into the wall
let's move it down to stand right on top
of our ground I'm also going to take it
and move it out a tiny tiny bit we can
use something like negative 2.49 just to
make sure that it doesn't intersect with
our wall so right now our plane has a
default material applied instead we want
to go ahead and create a material that
will emit light on to the rest of our
scene to do that let's right-click in
the project go create let's create a
material I'm gonna call this material or
light and I'm then gonna drag it onto a
plane on the right hand side here under
emission let's enable that and here we
can choose a color I've already found an
orange color that I like so I'm simply
going to paste it in here you can of
course use the same one if you want I'm
also going to set the amount of emission
to 1.5 so down here we can see that it
makes our material look brighter but in
a scene it's currently not really doing
anything first off we need to make sure
to rename a lighting but still nothing
is happening the reason why is that
objects with emission won't actually
emit light in real time now in order for
this to show we have to bake a light map
and to do this we have to let unity know
that our light as well as the rest of
the objects in our scene are all static
in other words our objects aren't going
to move so we can safely bake a light
map for them to do that let's select our
plane hold down shift and select the
room and monkey as well let's go to the
top right here and select static and now
you can see in here in the bottom right
corner that unity starts baking a light
map and right away we can see the result
this is by no means pretty yet but we
definitely have lighting in the scene
I'm gonna rename the plane here to
orange light I'm gonna duplicate it and
then going to go to the exposition here
and remove the minus to snap it to the
other side and I'm also going to rotate
it around the y
180 degrees finally I'm going to
duplicate the orange light material I'm
gonna rename it to blue light and then
gonna drag it on to the light on the
right hand side here I'm gonna select
the color and I have a blue color
prepared as well and I'm also going to
go and change the emission to two
finally I'll select the new light and
rename it to blue light so now in our
game view we can see that we have two
lights and this simple scene but it
doesn't look too good yet one of the
reasons why is whenever you import a 3d
object you have to make sure that the
object has light map URIs in some cases
you can get away by simply selecting the
object an enabling generate light map
UVs
this means that unity will automatically
calculate the light map movies for this
object if we apply on our room here you
can see not much changed that's because
when creating this room in my modeling
software I've already made sure to
create UVs for it as well but makes
to use this option if you haven't but a
scene still doesn't look that good let's
try and change the lighting properties
to do this we'll go window go and do
lighting and choose settings this will
bring up the lighting window first
because this is an outdoor scene I'm
going to go ahead and remove the skybox
material so I'll simply set this to none
right away you can see this darkens our
scene and gives it kind of a bluish tint
that's because the default ambient color
in unity is a dark blue if your entire
scene is indoors there really shouldn't
be any ambient lighting all the lighting
should come from light emitters within
your scene so we'll go ahead and set
this to a complete black we'll also make
sure to disable real-time global
illumination because again we want to
only bake our light Maps and you can see
right away our entire scene becomes dark
that's because so far unity has been
using real-time calculated lighting and
now unity actually starts baking a light
map again the result here is not too
impressive that's because we want to
configure our light mapping settings
first we choose what light map we want
to use we of course want to change this
from enlighten to progressive sometimes
when changing between the two options
you have to go down and deselect Auto
generate then go to the drop down arrow
and hit clear bake data and then we can
once again enable it you'll notice how
the entire scene again turns black and
it might say it's backing down here but
the result is also completely dark the
reason why is when using the progressive
light mapper we have to make sure to go
into our emissive materials so here's
the blue light and under emission change
it from real-time global illumination to
baked go ahead and do the same thing for
the orange light and right away you can
see the light mapper working in our
scene you can also see that it looks
very noisy and after while everything
suddenly looks smooth and the result is
already much better if you now go ahead
and make a change to a scene say let's
move our monkey we can again see this
noise reappearing what we're seeing is
actual light rays getting sent out and
as more and more gets sent out the noise
gets reduced and finally when the light
mapper has sent out all of its samples
it simply takes the result and blurs it
you can also see that because I have
prioritized view enabled the light
mapper will actually render the part
that we
looking at in the scene view first this
is super cool if you want to focus on a
specific part of your scene so now it's
time to play around with some settings
and the first most noticeable problem
that we want to get rid of is this weird
theme running down the monkey's head now
this seam is here because I've gone
ahead and manually uvd monkey and this
is one of the places that I decided to
put a seam but of course we want to make
this as hard to notice as possible and
one of the really cool tools that we
have here is what is called seam
stitching this is something you enable
per object so if we go ahead and select
our monkey switch to the inspector and
go under the mesh renderer under
lighting here we have a separate
category for light map settings and here
is a property called stitch themes if we
now enable it you can see that
immediately the seam gets blurred out
and becomes way less noticeable I
definitely recommend turning that on for
most complex objects and our lighting
actually already looks okay one of the
things that we can do is easily decrease
the light map size this is simply the
end resolution of our texture because
our scene is very small we can
definitely decrease this to 512 as you
can see the end result is pretty much
the same and we've just more than half
the size of a light map we can also
choose whether or not to compress the
light map this will heavily reduce the
file size but it can also add a lot of
weird artifacting to the lighting in
fact we can see an example of that right
here these weird pants are because of
compression on the light map so let's
try and disable it you can see right
away our light map increases in size but
the banding is now gone we can also see
on the side of the monkey here on the
ear we're getting these weird purple
colors now these are definitely not
supposed to be here this is what we call
bleeding it's when data from one part of
the light map leads into data from
another part of the light map if we
switch to the global maps tab here we
can actually see the two textures that
were generated for a scene notice how we
can recognize different parts of the
scene in these maps we have different
walls from the room we have different
parts of the monkey if some of these
elements start to bleed into each other
we get this weird result so to try and
get rid of this I would start by
increasing the light map
patting let's try and set this to eight
right away we can see that the problem
still occurs let's now try and increase
the light map resolution let's try and
increase it to a hundred now that
definitely helped but we can still see a
tiny bit of bleeding so let's try
increasing them a tiny bit more and
there we go with the problem is now gone
keep in mind that every time you
increase the light map resolution it
will also take longer for your light map
to bake so some of these settings you
might want to leave fairly low while
adjusting and then when it's time to
bake the final result you can bump them
up this also applies to the number of
direct and indirect samples sambal is
basically just another word for Ray so
this here is the number of briefs that
we send out per Texel in order to
determine the direct lighting in our
scene and this here is the same but for
indirect lighting in other words if we
go ahead and increase these we should
get greater detail in the result we can
also adjust the number of bounces that
we want to calculate we could say set
this to 3 and this could take a while so
you might want to go off and do
something else and you can see the
result is a much smoother less noisy
light map and the lighting will
definitely be more precise this is
always one of those settings that I just
leave by default when I'm setting up the
scene and then crank all the way up when
it's time for a final render especially
because the number of direct samples and
bounces don't have any influence on the
size of our light map they just increase
the time it takes so I'm gonna set these
back and finally I'm going to enable
something that will make everything look
much much better I think this is
everyone's favorite setting to enable
I'm of course talking about ambient
occlusion ambient occlusion
is the shattering that occurs between
two nearby objects as you can see in the
corners of a room here in the crevices
on a monkey and where our monkey sits on
the ground so right now it's maybe a bit
too much I'm going to decrease it to 0.1
and also decrease the max distance to
0.7 finally if you find errors in your
light map that you just can't get rid of
by adjusting these settings it might be
because it happens during unities
filtering stage this is why unity takes
the fairly noisy light map and applies
some post-processing in order to smooth
it out luckily we can adjust how unity
filters the light map to do this we go
to filtering and you can see what
happens if I disable this
this is the finished light map in its
raw form from here we can go under
advanced and we can add different types
of filtering I find that in 90% of cases
I use caution and here you have the
possibility to dial down the amount of
filtering both for the direct and
indirect lighting as well as the ambient
occlusion
for indoor scenes I often have to go in
here and decrease the filtering on the
indirect radius as you can see the scene
still doesn't look noisy and it often
removes weird lighting glitches but for
this scene we can simply keep it add
Auto finally if your scene is overall
too dark you can increase the indirect
intensity or give your entire seen a
boost using the albedo boost one of the
questions that I get asked the most is
how do you add glow to your lights there
currently is shining on to the
environment and that's fine but most of
the time when you look directly at
lights in real life or through a camera
they will have this sort of glowing halo
effect the answer is we don't actually
add this through the lighting system
instead we use post-processing effects
to do that we'll go to the asset store
will search for post-processing select
it hit import and import again then we
want to select our camera go to the
inspector and here we want to add a
component called the post-processing
behavior this will enable
post-processing on our camera we can
then switch to the game you to see the
result right click in the project panel
go create and we'll create a
post-processing profile which will store
all of our settings we called it CC for
color correction select our main camera
and drag in our CC object and now when
we select our CC object we have all
these different post-processing effects
the one that creates glow for our lights
is the one called bloom and this might
be a bit too much so let's open up our
bloom let's decrease the intensity to
0.3 and let's also decrease the radius
to something along 2.8 and while we
added we can also add a tiny bit of
color grading let's enable that open it
up and we'll change the tone mapper to
filmic will also increase the exposure a
bit and maybe we want to decrease our
bloom even more and finally we can go in
and add a vignette and we probably want
to decrease the intensity on this one as
well so there you go that's the basics
of lighting a scene in unity
that's pretty much it for this video if
you want to learn more about lighting
such as how to set up real-time lighting
in unity definitely let me know in the
comments also make sure to check out the
complete unity 3d game development
course simply click the link in the
description to get started and get a
discount along the way on that thanks
for watching and I will see you in the
next video thanks to of the awesome
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