Blender 2.7 Tutorial #73: Collecting & Piling Snow #b3d Video Lecture | Learn and Master: Blender (English) - Professional Skills

[Music]
well hunter Brooke 7371 drew
two-point-seven in this video we're
talking about collecting snow in other
words snow that slowly starts to collect
on the surface of an object in a snowy
scene and eventually the snow will start
to pile up over time if you have not
witnessed this phenomenon I'm going to
bed one night without there being snow
on the ground and waking up and seeing a
big pile like a foot of snow on
everything in the morning it's a really
magical thing I'm I live in Canada but
not a very cold part of Canada so this
is a fairly rare thing for me but I want
to create this story on how to make this
exact effect just in time for the
holidays so on the screen right now you
can recognize what looks like the
results of part 69s snow series in which
I talked about how to create a scene
with falling snow using particles in
blender if you've not seen that tutorial
on how to create falling snow I'll
predict that on the screen right now you
can go ahead and check that out and now
seeing we actually are in my video we
actually create a particle system with
us no object so it's no material and we
make snow falling it looks realistic
better have particles that are falling
around and some nice motion blur as well
on the snow falling as you can see but
in this video we get some particles of
snow collecting on specified surfaces on
objects in the scene in this case a
monkey yet let's go ahead and check out
this result and I'm gonna show you a
more time-lapse version with a higher
piling snow on a surface of a monkey
head so as you can see here now unlike
in part 16 I actually have snow
particles collecting on the surface of
the monkey head of course takes a long
time for snow to accumulate on objects
often you know at least 15 minutes or
several hours for a pile or at least a
layer of snow to collect on objects
depending on the speed of the snow but I
have a time-lapse version I'll be
showing how to do both something like
this and something that's more like this
where you get the accumulation of a pile
of snow on an object in this tutorials
we'll be talking about that let's go
ahead and jump in though so I'll go into
blender I'll sort of brand
you've seen I've got my screencast keys
going so you can see what keys I press
most of the time and what mouse buttons
I press down here in the bottom left
corner of my screen I'm gonna start my
scene by setting up a basic snow falling
scene so I'm gonna get rid of this
default cube I'll press X on my keyboard
to delete the selected cube I'll press
shift a I'm gonna keep on going up the
add menu and I'll add a mesh plane I'll
press S on my keyboard to scale it up
and then I'll click to make it bigger
I'll move it straight up just above that
lamp object there and make it a little
bit bigger I mean order to make a
particle system you have to go over with
your selected plane that's the emitter
object and we're gonna go over the
properties window and go to the
particles tab and I'll make a new
particle system and by default it adds
an emitter a particle system to your
selected object the only other type of
particles are hair particles and so now
if I scrub through my timeline you'll
see kind of a default particle system
with its default settings going along
but of course when you're using these
cycles render engine which I have not
yet switch to so I'll do that right now
I'll switch to cycles and not under
render but cycles but when you use
cycles the particles don't look like
anything so if actually create these
snow particles to do that I'm going to
go to a different layer I'll just go
down here to that layer right there
which has nothing in it and I'm gonna
press shift a actually I accidentally
clicked over there so I'll press I can
just apply a 3d cursor back in the
middle precisely with shift s shift s
brings up your snap menu and then you
can select cursor to Center okay so the
three cursors back in the middle of my
scene I'm gonna press shift a I'm gonna
add a ecosphere that's a sphere made out
of triangles and I'm gonna use an add-on
called the cell fracture add-on if
you've not seen my video how to create a
shattering the object and that video I
talked about the cell fracture at are in
more detail in order to get the cell
fracture and all you need to go up to
file and user preferences it's actually
built into blender but you have to
enable it so under and user preferences
under the add-ons tab if you just do a
search for cell C e ll you'll see it
here
you need to enable it and
save user settings and then you can
close it and it'll be on your tool shelf
over here under the first tab tools it's
right there cell fracture so basically I
want to break this up into separate
objects into shards
that'll be individual snowflakes so I'll
click on self fracture I'm not gonna
make let's say me 18 or 16 shards out of
this main shard and I'm going to enable
recursion once that means they can break
up into smaller pieces
great I'll press ok it's gonna go
through and make the shards in the next
layer over so now you can see in this
first layer I still have the original
ecosphere button this layer here I have
all my pieces um at this point I want to
make a material to go in all of the
shards and so I'm gonna divide this
large window into two I'm gonna grab
this little triangle area and left-click
and drag it straight down to divide the
larger window into two I'm gonna make
the top window into a node editor window
to make my materials I'm gonna actually
select all of these shards in this layer
in this scene so I'll press a on my
keyboard a few times until everything is
selected
I'm gonna go up to the materials tab and
I'm gonna add a new material again with
the cycles render engine and then I'll
actually only add that material to the
active that means the most recently
selected object and when you press a it
kinda selects one as the last selected
object the active object will just be a
random one then we have a default
diffuse material now I don't want that
I'm actually gonna get rid of this
diffuse node and I'm gonna press shift 8
I'm gonna add a mix shader' so sheeter
and mix if you have not seen my video on
how to it use nodes and the cycles run
your engine I'll link to that on the
screen right now I'm going correct
fastest because we want to get through
to making snow piling on an object so
this is just setting the scene up I'm
gonna connect up the mix shader' to the
surface material output and I'm gonna
add in a glossy shader I'll connect that
up I'm gonna add in
a mission shaders of shader whereas
emission I'm gonna connect that up I'm
gonna mix this glossy and kind of glowy
material with a translucent material and
you can kind of experiment how to make
the best of snow material this is not
the best snow material at all I can
press shift a so I'm gonna mix this
result together also I'll add a shader
mix shader' right there and I'm gonna
mix that result together with this node
with a translucent shader right there
and this is not meant to be photo real I
kind of just guess it's a quick sort of
realistic or not quite hard surface
result but the problem here is that this
material is only on one of the shards
and to copy it to all the other shards
I'm gonna press ctrl L on my keyboard
and then I can select material so this
is the ctrl L brings up the make links
menu and this is how you copy things
from one object to another including
things like modifiers we'll do it in
just a second but we'll do materials now
so that actually copied the material
from the active object or the other
things in the scene I'm actually going
to make everything in the scene smooth
and/or everything that I have selected
in the scene smooth and I'm gonna add
the subdivision surface modifier to all
the snowflakes but of course it adds it
to only the active one I'll turn up view
too as well so I have to press ctrl L
again and then I can select modifiers
and that way it'll copy the modifiers
from the active object to all the other
objects and as you can see now we have
smoothed out snowflakes it does add you
can tell by this kind of aqua colored
edge adds kind of a sharp mark sharp
edge that's why you don't get nice round
and snowflakes but you get snow fix that
kind of have a hard edge and that's okay
they're gonna be quite small and I think
that's actually okay because snowflakes
are unpredictable shapes so okay we have
a bunch of snowflakes with the right
material on it I'm gonna select all of
those pieces I'm gonna make them into a
group because that's what particles need
so I'm gonna press ctrl-g control
we'll make the southern objects grouped
ina named this group over here snow and
now we can start to actually work with
our particle so back in our main layer
and our scene I'm gonna select my
emitter object this snow does not look
like anything if I were to render it out
right now that's because under the
particles tab under the section called
render we have to specify an object or
in this case a group I'll select snow
and so now you can actually see all
those little shards falling down now
we're gonna have two particle systems in
our scene we're actually gonna have a
particle system right now that is
following snow and we're gonna have a
particle system that's actually coming
off of a secret hidden object that was
actually gonna be putting them on the
surface of the object from the seat in
this case we're gonna make a monkey head
and that secret hidden object is gonna
be animated going upwards emitting non
falling particles on top of the monkey
head you'll see that in just a minute
but because of that because we have
particles in the scene that do not fall
we actually turn off gravity in the
entire scene so I'm gonna go up to the
scene tab that's right here it's not the
world tab it's the scene tab I know
uncheck gravity so now if I kind of
scrub through my timeline our particles
are not doing the same thing they are
going upwards and that's because the
normal the direction of this emitter
face is pointing upwards and we actually
have in our particle settings with this
object selected the velocity the initial
velocity of particles in the scene are
at 1 that's a value 1 going in the
direction of a normal of the face of the
emitter object so I'm actually gonna
turn that I'll select that and type in
negative 1 and that way it'll be going
in the opposite direction and so now
it's gonna be going down if I press alt
a to play
that's the keyboard shortcut for play it
sold a you consider partly so parts are
falling in the direction that I want
they don't last nearly long enough
though so under emission with the
emitter object selected I'm gonna say I
want my snow to start out actually
before 0 I want to already be snowing so
I'm saying negative
200 and I want to end at the end of my
timeline so let's say 250 I want the
lifetime of all the particles that's
know to be longer I want to be at least
300 or so and I don't care if they
randomly die earlier or not other
particles end or die earlier or not so I
can turn this up if I want so now if I
press play
it actually will need to go through
twice because you can see it weren't
starting right at the beginning even
though I have negative 200 as their
start time these no particles should
beginning to move this a little bit just
so that it kind of recalculates out
sometimes there are bugs with a particle
system and so you have to wait for it
just to go through again or just move
things a little bit and you're seeing to
make it recalculate the simulation but
as you can see now we have nice falling
snow that actually is in the scene at
beginning of the scene if I want things
look a little more random I can turn up
under physics roam Brownian pardon me
Brownian is kind of a jittering effect
that we want so I'll turn that up a
little bit and as you'll see the
snowflakes will look like they're
drifting in the wind a little bit and
you can play with that value to your
heart's content I think that looks
pretty good the other thing we want to
do is turn up the number or turn down
the number of snowflakes depending on
our scene I might change this to 5,000
if I want more snow and of course it's
going to not be right at first got to
recalculate from the beginning again and
that's a lot of snow and that's good
because we wanted to start collecting on
the surface of an object so I'm going to
make a object middle of my scene of
course I'm monkeyhead so I'll press
escape I'm gonna press shift a on my
keyboard I'm gonna add a mesh monkey
I'll press s to scale it up and I'll tap
R and then Z to rotate it towards me and
maybe I'll move it up a little bit and
scale it down let's make it smooth and
let's give it a subdivision surface
modifier to make it nice and
smooth and let's give it a nice just
simple diffuse material I'll make it a
nice blue color because he's cold and we
can't see the blue color in the viewport
because we have changed our viewport
shading over to materials there he's
blue and so now if I look at my scene
he's there let's go ahead and make the
background of a scene black like we're
looking at a scene at nighttime so this
is the background color of the scene
when it renders out not in the viewport
and let's go and make this a look a
little better I'm under the camera tab
I'm going to enable motion blur and that
will kind of sell the snow effect I'll
turn my shutter to a higher value which
means it'll be more blurred or any
objects that are moving will have more
motion motion blur so one point to I
found it's a pretty good number I'll
look for my camera I'll press M to bring
up the side panel I'll check this law
camera to view so now I can actually
orbit my camera to move the camera
itself and I'll set the scene up just
like that how was my lamp in my scene
it's a point lamp I don't like that so
I'm gonna make it into an area lamp I'm
gonna make it square and have a size of
five and it's toting the wrong spot
right now so I'll go to my top view and
wireframe and I'll rotate it and put a
rate about like that so it's kind of by
the camera and I move it down a little
bit and I might have to use nodes over
here in the under the lamp tab and make
this strength higher and let's just go
ahead and see what that looks like just
so you have a nice scene before we start
adding the snow collecting on it and
under render that's what it looks like
it does not have the motion blur effect
until we do an actual render so let's go
ahead and do that just so we can kind of
see before we move on and there we go
we've got some nice motion blur
happening on the snow particles the
particles maybe are a little bit small
and that is under the size slider in the
protocol system setting so I can select
the emitter object in fact I don't want
the emitter object to show up so under
render I'm gonna uncheck emitter so it
won't actually render that plane out and
under sighs no slices located a few
different sections but they're all
linked together so if I change the size
here I can make this no effects bigger
but it might also be in a different
section this one happens to be in
physics there we go so we've got a snow
scene we have to readmit it because I
changed the size of the particles and
I'll press shift-z to go back in to not
render view great so now we get to the
meat of this video and that is to make
snow collecting on the head of the
monkey I'm actually gonna turn off this
particle system so with the emitter
object selected the plane I'm gonna go
up to the top of the emitter tab or the
person's tab and I'll just hide the
particles for now I'm gonna select the
monkey hat I'll break out of my camera's
view and I'm gonna go into edit mode of
the monkey head and I want to select and
duplicate the faces that I want these
snowflakes to land on of course I don't
want the cell face to land on the bottom
of the monkey head down here I'll go
into solid view so we can see what's
happening
I want the particles to land on surfaces
that are on the top so I'm gonna select
those with a right click and holding
shift so I'm gonna stretch the faces
that I think snow will land on it won't
really land on these ones too much
although it'll collect in that groove
there so I like thought face maybe that
face a little bit and I'll select the
ones over here as well I have the monkey
head rotated so we can't just mirror any
kind of selection here we have to just
select these things manually
to do that and that oops that emitter
object keeps getting in the way I could
hide it but I'm just going to quickly
for that I'll select these faces as well
and I'll select the monkey's eyebrows
and of course if you multiple objects in
your scene that snow is collecting on
you'll need to do this for each object
so it is a little bit of a painstaking
task but it doesn't take too long to do
once you do one it goes pretty quick do
I want the snow falling on the front yes
I do
these faces as well absolutely if I want
to see this a bit better I can turn off
or just hide these other vision surface
modifiers so it's not smoothing out
those faces more than I want to and I
think we're just about done here it's
that face one that I want robably don't
want that face there okay I think we've
got all the faces that we want snow to
land on selected so let's go ahead and
duplicate these faces and then separate
them into their own object so what these
face is selected I'm gonna press shift D
on my keyboard that will duplicate shift
e duplicate objects and I'm gonna right
click to put these faces back into the
exact same spot so now watch out we have
two faces in the exact same spot now for
all these selected faces I'm gonna press
P and P it's a funny keyboard shortcut
it's actually the separate my menu and
I'm gonna select selections we're going
to separate the selection my selected
duplicate faces and I'm still on the
edit mode of the original monkeyhead
object so I'll go back into object mode
and now if I right click I can select
that new separate I'm a top surface of
the monkey head perfect it also has the
sub surface modifier on it plugin i
press ctrl-z to put it back where it was
and now we can re smooth it out I can
Reece move out the monkey head and as
you can see now we have a separate
object and this object is going to be
the object that actually particles are
coming off of and we're gonna animate it
moving up and that will make sure that
the snow still up as it piles up you
might want to actually go through with
this selected mesh and make sure that
the corners are
doing anything funny like this because
of the solar vision surface modifier on
the entire monkey head when you delete
parts of it the smoothing might change
the shape of the object so I might go
into edit mode and just sort of select
some vertices and edges and faces and
kind of pull them in a little bit to
make sure that snow isn't landing kind
of off the end of the ears there but I
even move them a little bit higher up so
that snow isn't landing on kind of the
the side of the ear like that and you'd
go through and make sure that's true for
all parts of the head but I'm not going
to bother um in order to make snow
accumulate on the full monkey head we're
actually gonna have particles emit from
this surface and they're gonna be left
in place as this surface actually moves
upwards so this is the emitter object
that will not show up when we render but
the particles will be left behind and
sort of will just stack up if we have
enough so I'm gonna undo to move that
back down I'm gonna make a new particle
system so I'll go to the particles tab
I'll click on new we have any mitr great
I want to select that same under the
render tab the same group of snow
particles just like that and if I scrub
through you're gonna see that because
there is an initial velocity value set
to 1 there they're moving we don't want
them to move at all
so under velocity we want to change this
normal value to zero and press Enter
so now because we have no initial
velocity and because there's no gravity
in the signature and gravity off a
little but a few minutes ago then if we
go back and re simulate these particles
are just going to appear over time and
they're not gonna go anywhere until the
particles themselves end or die because
they have a lifetime so let's go ahead
and change that life I can change some
of the settings I'll select that surface
I'll go to my particles tab I want the
particles but let's start right away so
under the admission I'm not gonna have
them sorted out frame 1 they'll starting
to be at frame 20 sure they're gonna
have a lifetime of forever
so I'm just going to put I
thousand if you have a longer simulation
like a time-lapse or longer animation
rather you might have via this lifetime
be as long as you need to the very end a
generation because you don't want your
wrestling snowflakes to disappear most
likely the end is gonna be the end of
our timeline so 250 and I might change
the number of particles to depending on
how quick a lot my starting to
accumulate I'll need to change this
value so now if I press alt 8 to play
I should have the particles appearing
over the surface of the monkey head I
believe we changed the size of the
particles a little bit so I can make
those bigger or smaller maybe the bigger
you can kind of see what's happening
here and that looks pretty good to me
now if I want particles to really stack
up like after several hours of its
snowing and there's now a pile of snow
I could animate this emitter object so
I'll do that I'll go back to frame say
20 when the snow starts and I'm gonna
press I to insert a keyframe with the
emitter object selected so I'll tap I
I'm gonna select location rotation and
scale because we're actually gonna scale
the object a little bit and when I do
that it makes a keyframe right there at
frame 250 I'm going to move that object
up I'm also gonna scale it a little bit
so I'll tap s I'll scale it down little
bit to make it just a little bit smaller
because when snow accumulates it goes
pretty well straight up but it also has
to go a little bit inwards the top
surface of the snow is a little bit
smaller it also gets point here as it
gets to the top so I'll tap s and then Z
to make it just a little bit like that
and because we don't have automatic key
frame insertion turned on that red
button is not impressed
I ain't you again tap I and select local
scale to assert a keyframe so now if I
scrub through and that object will move
up and as you can see particles even
though they're not on an object are
being put up into space
now this is where the ratio of the
amount of particles versus the speed of
this object really comes into play as
you can see that it's no particles
nearly packed together tightly enough
and I think I might even have these
particles way too big so we might need a
lot more particles of snow to make it
look like there's actually a pile of
snow so I didn't actually turn this
value up the number of particles up
which again is the number of particles
that will be moved from frame 20 our
start time up to frame 250 I never -
news to a very high number but before I
do that I'm just gonna save this file in
case blender crashes so I'm gonna go up
to file and save I'm gonna save this to
my desktop I'm gonna call it snow
collecting - 0 0 1 sure and I'll change
this value up to maybe 10,000 and press
Enter and of course we have to reseal 8
and so now the particles will land or
appear and they will stack up and
hopefully that some particles will kind
of contract a little bit and not be
straight up but be a little bit smaller
and point here at the top now are these
snow particles tightly packed enough and
are they the right size well probably
not so I'll probably do maybe even
20,000 like that and willing to re
simulate before I do that though I won't
look at least no particle size in my
scene so I'll go back to the emitter
object right there and I'll show that
system again so now we can see the size
of the falling particles versus the size
of the particles on the monkey head and
as you can see they are probably too big
on the monkey head so I'll select that
emitter object and I'll turn down my
size which is under physics here I
believe it's also in a few other places
as well now here's the thing I actually
had to render the scene out many times
when I was practicing for this video
because because I have falling snow it
does not look like a time lapse and the
snow is collecting as if it were a time
lapse again it takes a long time for
snow to collect especially in a pile so
I'm actually going to open up my
dopesheet window and edit my animation
so of this emitter objects the part of
the head is
not going ups nearly so quickly I got a
little bit of accumulation that may be a
little bit of piling but not so much if
you were to make this snowfall a lot
faster like if you were looking at a
time lapse video of snow falling then
you could have snow falling and actually
look like it's collecting or you could
make your animation have a whole
discussion of snow and then you could
start your animation there so if you
already want piling snow you could do
this ahead of time and only render out
from like frame 190 or frame 250 you
onwards that would be okay but I'm gonna
actually edit this animation so I'm
gonna make this window the timeline a
bit taller I'm gonna divide it into by
grabbing this little cross hatched area
and this clicking and dragging straight
down I'm gonna make this upper new
window into a dopesheet window and
actually the emitter object is not
moving at a constant speed it kind of
starts slow it speeds up and then it
slows down at the end and that's because
of our keyframes interpolation and so
I'll press T on my keyboard with these
two keyframes selected T will bring up
the interpolation window and now I can
set the interpolation to linear that
means that the emitter object will now
move at a constant speed again that was
T and linear by default it's set to
bezzie a which kind of eases in an ease
out the speed of any moving object so I
don't like how much it's moving up you
might like that it will look like snow
is just sort of appearing on the monkey
had way too quickly for the speed of the
falling snow so I'm gonna go to that
frame there I'm gonna move the monkey
head emitter object down and scale it up
this little tiny bit and scale it on the
z-axis a little bit back and I'm gonna
put right near the head but not nearly
so far away and I'll scale it back down
on the z-axis
so now I'll tap I on my keyboard to
insert a low quote scale keyframe and
we'll have to resume you late and I got
to refigure out how much snow should
actually be collecting based on the
speed of the snow and I just sort of
eyeball that this is way too much snow
for just the surface of the monkey had
it based on the speed of the snow and
it's
and that we have so I'm gonna turn down
the number of particles maybe to even
something like 200 again snow collects
slowly so now we have some protocols
landing on the monkey head and I still
think this is moving way too fast so I
might actually just get rid of that
keyframe just that one pardon me I had
both luck that's why I'm did that and
I'll just move it up maybe a tiny tiny
bit ever so little probably not even at
all and I'll tap I look cross-scale so
now it barely has any motion and I'll
resume you late that and as you can see
now more appropriately slowly snow is
slowly collecting on the surface of the
monkey head if I want to make a very
long animation or a time-lapse animation
you would actually see snow collecting
the very last thing we'll do here is
we'll set up some depth of field to
really sell that snow effect and that
it's not on the camera so I'll press
escape on my keyboard let's go ahead and
zoom out in fact on the particle emitter
at the the head have I unchecked under
render emitter no I have not I want to
uncheck emitter on the emitter monkey
head a partial head object so that it
does not actually render out object the
last thing I want to do here is add an
empty to the scene I'll press shift a on
my keyboard I'm gonna add a lot of mesh
it's an empty I'm gonna add an arrows
empty it's right there in the middle of
my scene at my 3d cursors location I'm
gonna put it up at the front of the
monkey head right at the surface right
there so it focuses nicely on his face
with the camera selected I'll go over to
the camera tab in the properties window
and under a depth of field we want the
camera to focus on that empty you can
actually type in the name of the object
in this case it's just called empty and
I'm gonna actually go into rendered view
and I'll look through my camera with the
zero key on my numpad and I'm gonna
crank up the radius size to an
appropriate amount if I go too high it's
just gonna blur out everything that's
behind an in front of the monkey head
from the camera
perspective so I have play with this
value you can hold shift actually and
left click and drag to slowly get the
value that you want that's a little bit
too much there so I'll keep going
holding shift and left clicking and
dragging and again we don't have any
motion blur showing up in the viewport
shooting rendering mode we ought to have
two rendering out to see what that looks
like but it's looking pretty good to me
it's a little bit less there actually
okay let's go ahead and do a quick
render at the very beginning of our
scene and at the very end of our scene
if I go up to the camera tab and press
render we should see all the effects
including the motion blur so at the very
beginning that scene there is no snow on
the surface of the monkey head I'll
press escape in fact I'm gonna change my
rendering device to my video card GPU so
I can actually render Oh quicker and
let's go to the very end of the
simulation when I have some snow
collected on the monkey head and I'll
click render and as you can see now we
have a render of a monkey yet that has
some collected snow book that will be if
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