Blender 2.7 Tutorial #87: Volumetric Lighting in Cycles #b3d Video Lecture | Learn and Master: Blender (English) - Professional Skills

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welcome our 87 money's thunder 2.7 in
this video we'll be talking about
volumetric lighting in other words
atmospheric lighting that sort of looks
like fog or dust in a room when a light
shines through it this can really add a
sense of realism to your scene and it's
very easy to do but in this video I'm
gonna be showing you two examples and
going through exactly how you can
customize your scene and it's actually a
few different ways that you can add
volumetric lighting to a scene and are
two examples we're gonna make a
spotlight on a monkey head that's in the
middle of a floor and we're also gonna
make a room with light shining through a
window on the other side of the room and
you'll see how both those teams are made
again two different ways of course if
you liked this video or if you learned
something go ahead and click on that
like button below this video on YouTube
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whenever I upload a new tutorial let's
go ahead and jump in I'll click on my
splash screen to get rid of it the first
thing we're gonna make is a spotlight on
a monkey head I'm gonna go ahead and
with the default cube selected I'm gonna
press X on my keyboard and then click on
delete to get rid of that I'm gonna
press shift a on my keyboard shift a
brings up the add menu I'm gonna go to
the mesh category and add a mesh plane
that's gonna be my ground I'm gonna tap
S on my keyboard to scale up and I'll
move my mouse out and click I'm gonna
press shift a again on my keyboard to
bring up the add menu I'm gonna add a
mesh monkey head that's gonna be our
subject this is Suzanne the monkey head
but Suzanne has very large faces or
polygons so it looks very blocky so on
the tool shelf and if you don't have
that up you can press this little + or
the T key on your keyboard
I'm gonna set its sheeting with it
selected to smooth I'm also gonna go
over to the side properties window over
here
and go to my wrench tab which is where
you add modifiers I'm gonna add a
subdivision surface modifier that will
make it look very nice and smooth and in
the subsurf modifier settings I can turn
the view
so divisions up to one there we go let's
go ahead and add a material just so we
can kind of get a nice look here in
order to add a material though I'm gonna
switch over to the cycles render engine
and that is not the engine that you use
by default you could change that up here
the default is the blender render engine
in this version of blender so I'll
select cycles and then everything the
way we add lights and nodes and
materials all changes so if you get that
step do not forget that step because if
you do everything will look different
from this point on it's easy to miss
that if you're new to plunder with the
monkey head selected I'm gonna go to the
materials tab and because we're using
cycles nothing is here until I click on
new its adds a new material to the
object and by default it uses what's
called a diffuse shader I'm not gonna
use that though I'm gonna switch that to
a principled psdf shader and this is a
new shader in blender at least this
version or last version I'm not sure
exactly when I came out but this is
basically a material figure that can do
pretty much anything all in the same
shader type so you can do really
anything here you can make it shiny or
mirrored or dull and it'll be very
realistic but I'm just gonna go ahead
and change my base color so I'll click
in that white area and I'll change it to
green I don't see that in my window
though because my viewport shading is
set to a solid so I'm going to change it
to material and now I'll see the actual
colors in my scene but let's go ahead
and get on to lighting I'm gonna select
the lamp in my scene but it's just a
point lamp it's just one little speck
that shines light I'm gonna change that
to a spot light and to do that I'm gonna
select it and then in the properties
window I'm gonna go to the lamp tab and
then I'm gonna change it from a point
lamp to a spot light this spot light has
way too wide of an angle though so we're
gonna change the size under this spot
shape section down just by clicking and
dragging in that section to make it you
know more of a spotlight shape and I'm
gonna tap G on my keyboard to grab it
I'll just move it up maybe I'll make it
a little bit more narrow now you can't
really easily see where the spot light
is gonna exactly shine and the way you
can fix that is you can check this
little check
box that says show cone and when you do
that you can really see where it is in
order to rotate it though I'm gonna
double tap R on my keyboard or R really
quick and then I could just move my
mouse in a circle and if you can control
it it's a little bit tricky then you can
rotate it however you want so that's the
R key twice quick on your keyboard then
it'll let you spin it kind of
organically if I just were to render
this scene right now I don't go to my
camera tab I'm gonna click on a render
but before I do that I'm gonna press 0
on my number pad
that'll go through my camera if you
don't have a number pad on your keyboard
you can go down to view and camera right
there that'll break you under the camera
or get you into the camera that's how
the scene will look but I want to zoom
out a little bit so I'm actually gonna
go it to the side in properties panel so
I can tap in on my keyboard or just
press that little plus and if I want to
control the camera through the camera I
can check this little checkbox under
view it's called lock camera to view
once you have that checkbox selected you
can then just orbit your camera you can
select an object and it might rotate
around it and then you can just easily
position the camera if you don't have
that checked when you try to orbit
through the camera it'll just break out
of the camera it won't let you move the
camera when you're looking through it
unfortunately so that's that solved
there I'm gonna zoom out and then kind
of pan around and so I have a good angle
now and let's go ahead and see what that
looks like I'm gonna do a quick render
and as you can see it does not look that
great and we don't have that atmosphere
what I'll do is I'm gonna change my
background to black that's the world
color and order to do that I'm gonna go
to my world tab I can click right under
surface I can click on this little box
and choose just black let via color
picker
but in order to add volume metrics there
are two ways of doing it really you can
make volume metrics in your entire world
in your scene or you can specify it one
zone
in other words an object like a big box
that's gonna contain volumetric or a
volumetric material and so if you do it
that way you can limit where the dust or
fog is in your scene but what I'm gonna
do is I'm just gonna click on use nodes
because that lets me add volume this
section is now here because I clicked on
use nodes to my entire world and so what
I'm gonna do is I'm gonna select volume
it right now it has no volume I'm gonna
select volume scatter and when I do that
I get some options what I want to do
here first is change the color to
totally white right now it's a little
bit darker than white so I'm gonna slide
that up and I'm gonna change my density
if I were to render this right now I
think I would probably see black I think
I'm actually gonna try that I'll render
that out yeah I see entirely black and
that's because my world is basically now
totally solid there's no light going
through it because it's a solid volume
my entire world so I'm gonna press
escape on my keyboard in order to change
that again under the world tab I'm gonna
change the density of my world to zero
point one instead of just one and I'll
press Enter and now if I go back and
render my seam
I see nothing because my light is way
too low it's not bright enough so I'm
gonna go ahead and press escape let's go
ahead and select the lamp if I go under
the lamp tab now with lamp selected I'm
going to click on use nodes and that way
I can change the strength I'm getting to
the strength all the way up to let's say
about five thousand because we now have
a volume we have fog that actually
absorbs some light in our scene you need
to have a brighter lengthen you normally
would I would probably help this down
and about a thousand if I didn't have
volumetrics in my scene so I'm gonna use
five thousand let's go ahead and go back
to the camera tab and render this out
and as you can see we have a little bit
of fog but again the light is still way
too dark so I'm gonna press escape on my
keyboard really quickly I'll change the
strength of this lamp up so let's say
15,000
that's one too many zeroes I think and
I'll press ENTER and I'll render one
more time okay so we have our effect I'm
actually going to fix a few issues here
my nap is still too dark but also I'm
getting these white and colored specks
in my scene these are called fireflies
and their remnants of a error or bug
with the cycles render engine so this is
actually a very simple fix if you have
too much too many white speckles in your
scene that's an easy fix if I press
escape what I'm gonna do is change my
lamp brightness up to let's say 25,000
and that's one too many zeros there we
go and I'm gonna go under the render tab
and under sampling what I can do is I
can clamp the indirect light bounces in
my scene
you have clamped direct and clamp
indirect again this is under sampling
under the camera tab I'm gonna clamp
direct I'll just change that to one and
press Enter let's go ahead and see if
what this looks like after we render out
again alright so there's my red seam
that looks pretty good
I would probably adjust the light to be
on the other side of the character so it
was shining on the monkey heads face but
there you go let's go ahead and make the
next next example because I want to show
you how to make your atmosphere limited
to one area in your world so let me go
to file and new and then click on reload
startup file and I'm gonna take the
default cube and I change this into a
room but with a window so I'm gonna tap
S on my keyboard to scale it up by about
three or four times just like that I
want to make the room a little bit
longer so I'll tap S on my keyboard to
scale it but then I'll tap Y on my
keyboard so s and then Y and then I can
move my mouse and it'll scale it only in
that direction I'm gonna make a window
in this room but I'm gonna cut away one
of the ends first before I do that
though because I'm not gonna use the the
bevel tool to make the window or at
least the the bars in the window I'm
gonna go down to object and apply and
rotation and scale whatever you do
modeling and scaling and beveling it's
that's
good idea to use this or apply the
rotation and scale your object so things
don't end up stretching as you're
modeling them it's just a good practice
to do so apply rotation and scale like
that let's go ahead and press tab to go
into edit mode I'll select the end face
right there I'll press X and then faces
to delete that face this is where things
would be a little bit harder if I hadn't
applied the rotation of scale or at
least the scale I'm gonna go ahead and
make a few cuts so I'll tap control R on
my keyboard I'm going to go around the
side of the room and so I'll click and
move it up just like that if you're not
familiar with how to do loop cuts in
edit mode and blender up a link to my
video on the basics of edit mode on the
screen right now
I'm also now because this is just one
inch and I want the top of the window
and the bottom of the window I'm gonna
bevel this into two so I'll press
control B on my keyboard and then move
my mouse out and then I will click and
if you're not familiar with how to use
the bevel tool and butter up owing to
that video on the screen right now as
well I'll so you can go ahead and check
that out let's go ahead and press ctrl R
again to make another loop cut I'll
click and then click and then control B
to bevel it out so now I have the area
of my window but I want to put some bars
through it so I'll tap control R in fact
after I type ctrl R I'm gonna scroll up
once to make two bars in that direction
you can go crazy if you scroll I'm just
gonna make two I'm gonna click and then
right click I'll do the same over here
ctrl R click and right click now I want
to make these bars this edge loop and
this one and this one thicker so I'm
going to bevel them all together so and
we're gonna select a whole edge loop
like I do right now I'm going to hold
alt I'm gonna press a actually to be
deselect I'm gonna hold alt and I'm
gonna right click on that edge and then
you hold alt and right click on edge
when you're in edge select mode it will
select that whole connected edge and end
okay if I do that again but I hold shift
so I'm holding shift and alt I can
select that edge loop and maintain or
add to my original selection I'll hold
shift and alt still and I'll right
that one and now I'm gonna bevel all of
these just a little tiny bit so control
B and I'll pull my mouse out and now I
have some bars so I'm gonna go ahead
into face luck mode select all these
window faces and press X and delete
those faces so now I have a window let's
go ahead and press tab back into object
mode I want to give my wall some
thickness so I'm gonna go again into the
wrench tab and under modifiers I'm going
to add the solidify modifier and that
will give this some thickness I once you
add this that if I modifier you can
adjust the thickness I'm going to turn
it up a little bit and as you can see
the inside of our room gets some or gets
a bit smaller because the walls are
getting thicker you'll notice that your
walls won't be even most likely they all
trying to kind of taper a little bit and
that's because you have to check even
thickness and that will be fixed so a
little bit thinner and I'll press apply
I'm gonna make a little light shining
through that window and is gonna be a
fog stream on the shape of the windows
going through to the other side of the
room where the light is being cast so
I'm gonna take my point light and I'm
just gonna put it sort of rate I'm gonna
press actually one on my viewport on my
keyboard and then five to go into front
orthographic and that way I can move my
lamp with the G key up here and then
I'll go to my top view with the seven
key and put it right there so I think
that's lined up okay
I know put my camera at the end of the
room so I'll tap zero to go through my
camera view I'm gonna press N and then
check that lock camera to view and now I
can orbit to put the camera right about
there let's go ahead and do a quick
render or at least go into a few port
heating render to see what that looks
like you can see now that we're in the
inside of the room but the light is not
really bouncing around that's because we
have not selected B or switch to the
cycles render engine yet so I'm gonna do
that right now I'll switch to the cycles
render engine
and it looks a lot maybe more realistic
because it's not totally black but that
lamp needs to be brighter so I'm gonna
select the lamp over here in the
outliner window and then go to the lamp
tab and I'll click on use nodes and
change the strength of my lamp it's just
one little point remember I'm gonna
change it up to let's say a thousand so
now we have that effect in fact I'm
going to go up to five thousand so it's
nice and bright and if I split this
window into two I can just grab this
little triangular cross hatched area and
drag it straight down that's how I can
divide my window into two and I'm gonna
press 0 to break out of my camera up
here if I move the lamp you'll see that
I can move where the light is shining on
the wall so I can specify that and I
knew it further away I can make the glow
or the light on the other side of the
wall smaller if I move it closer I can
make it quite a bigger so that's up to
you I'm gonna move it to rain about not
saying right there
sure on the floor that's not quite
bright enough so I'll make that a bit
brighter let's say 8,000 and press Enter
now what I don't want to do this time is
I do not want to enable volumetrics in
my whole world I will though select the
color of the surface of my world and
make it black just we're not getting any
light seeping in through the other end
and what I'm gonna do in this case
though is I'm gonna add a box to my room
that's gonna encompass the whole inside
of the room pretty much and that box is
gonna have a volumetric material on it
so I'm gonna press shift a on my
keyboard to bring up the add menu I'm
gonna add a cube it's right there it's
way too small though so I'll tap s to
scale it up like that and then s and
then Y my keyboard to scale it a bit
that way I don't need the volume metrics
to go all the way out to this side of
the room but I'm gonna have them go all
the way the other end of the room so
that looks about good to me now I don't
want to have to look at this cube the
entire time so I'm gonna go over to the
I believe it's the object tab and I'm
gonna change the display type to not
that one not wire but I'm gonna change
the maximum draw type to wire so now in
my viewport that cube only looks like a
wire outline so I can still see into the
room now it's not gonna render like that
because I need to give it a material so
I'm gonna go to the trails tab click new
I actually do not want this cube to have
any surface material at all so I'm gonna
click on diffuse and say remove so now
it doesn't have material but I want to
have a volume material so I'm gonna
select volume none I'm gonna select
again that same volume scatter and when
I do that maybe down here in the scene
you can see I'm getting a little bit of
light coming through and you can see it
but again the density is way too high so
I'll tap 0.1 and press Enter and now we
have that scene this might be a better
option for you to use a cube that has a
volume scatter of volume material on it
instead of having your whole world have
that volume scatter
world-volume material you might find
that on slower computers it works a
little bit better for you but let's go
ahead and customize the look of this
dust or fog in the room in order to do
that I'm not gonna use just these
material settings I'm gonna split this
window up here into two and I'm gonna
change this window over here into a node
editor window and with that cube that
fog cube or dust cube selected I'm gonna
go to my material right there know that
as you can see I've got a volume scatter
I'm gonna press T and n to a hide the
side panels and I'll zoom in so you can
see this a little bit better I've got a
volume scatter a node plugged into my
material output what I'm gonna do though
was I gonna press shift a I'm gonna add
a let's say a shader I'm gonna add an
add shader so sheet her and she didn't
after I press shift a on my keyboard
and shakers gonna add together not only
a volume scatter material I'm gonna add
in to that I shall press shift aim a
shader we're gonna add a volume and
absorption and I'm talking about what
the difference is and why you'd want to
use that but I'll go ahead and connect
that up just by clicking and dragging of
course these two nodes can work together
to get any kind of a fog light that you
want in terms of how long the fog goes
on and how thick the fog is and how dark
your room is in terms of how much light
bounces around this volume absorption
I'm just gonna select it and press M on
my keyboard to mute it it makes us but
your space your volume will not allow
light to pass through as easily it will
make it so that the actual atmosphere
absorbs light and therefore you won't
get light reaching to the far corners of
your room so as you can see right now I
can see family but the corners and edges
of my walls
but if Eirene able this node by pressing
M to unmute it you can see that the room
gets a whole lot darker of course if you
have this enabled you can change it to
any value you like if I turn it to zero
point one the effect is much more
minimized but it still is a little bit
darker in the corners of my room then it
otherwise would be
this setting yeah we've already looked
at density yeah we know what that is
that means the density of the volume
material in your room this an astral P
I'm not sure I say that and a stroppy
has to do with light being scattered as
it passes through the actual atmosphere
and what that will mean to you is if
light is traveling through the room and
as it's going through the volume the
light is becoming scattered and less
focused and what that will do is it'll
make the fog appear to fade out more
over time so I change this and s repeat
I'm not sure to say that again to 0.5
and I press enter you'll notice that the
fog doesn't go quite to the highlight on
the wall if I turn this up to let's say
1.5 you'll see that we get barely any
fog and down
to about 0.8 you'll see the fog only
really goes to about there of course
when you're using this method of adding
volume metrics to your scene you still
might need to go to the camera tab and
to sampling and to clamp your direct
light bounces or indirect light bounces
pardon me to one so you don't get those
fireflies let's go ahead and I'm gonna
set up my GPU for GPU rendering because
in this version of blender blender 2.79
volumetrics does now work with GPU
rendering at least with nvidia based
graphics current so I'm gonna change my
device to GPU compute I'm gonna change
my performance at the bottom of the
camera tab so I'm using larger render
tiles by the way if you've not seen my
video on rendering and increasing
rendering speeds including how to use
Nvidia base CUDA rendering in blender
upper link to that video on the screen
right now but basically I have to have
bigger tiles when I render out so I'm
gonna use tiles that are 256 by 256
pixels that should be pretty good the
last thing I want to do to speed up my
renders and this is very important
whether or not you're using GPU
rendering or not is to enable
homogeneous rendering and that is done
under the world tab under settings this
homogeneous setting or homogeneous
setting was located somewhere else in
previous versions of blender but is here
now and when you check that it'll speed
up render time it's by assuming that the
fog in your scene is even it's not
textured or you don't have any smoke
like haze waves going in your scene if
you will let's go ahead and try
rendering it out but before I do I'm
gonna select my lamp and make it
brighter let's go to 15,000 and press
Enter and all go and render my scene
alright so that's how it looks let's go
ahead and zoom in on that looks not too
bad of course I could change and turn up
my render samples and even turn on
denoising in this new version of Thunder
2.79 to make the scene look less speckly
and the way you do that
as it is under the render layers tab
there's a new section in but our 2.79
called denoising and if you check that
and render your scene out with lower
samples like I have it'll make the scene
a whole lot less speckly but that will
be it for this video again if you like
this video if you learned something go
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all for watching see the next one but I
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you