Transcripts
1. 1 ) Introduction: Hello, everyone, and
welcome to this class. My name is Yesh,
and in this class, we are going to learn how to simulate a bomb
explosion in blender. This class is aimed at
complete beginners, and as long as you know
the basics of blender, you can follow along
with this class. In the first lecture,
we are going to learn the basics of fire
simulation in blender. So you do not need any kind of prior knowledge about
fire simulations. In the second
lecture, we'll move on to make the actual explosion, and the third and fourth
lectures are going to be aimed at setting
up the cycles and e renderers so we can achieve the look we want for our
explosion and render it out. We'll also learn the
basics of compositing a blender and add a simple
glare effect to our seal. After completing the class, make sure to create
your own project and upload your renders in the
project section of this class. In this way, me and other
students can view your project, give feedback, and take aspiration. What are
you waiting for? Let's begin.
2. 2) Intro to fire simulations: Everyone and welcome
to the class. In this lecture, I wanted
to talk about the basics of fire and smoke stimulations in blender so
that in the next lecture, we can jump right into creating
our nuclear explosion. I think it's really easy to make fire and smoke
simulations and blender. We need three things
for the simulations. First of all, we need a domain, which is basically going to be the boundary of the simulation, so Blender can optimize
the simulation within that boundary and not let the simulation
go outside of it. Second, we need a
flow object which is the object from within which the simulation
itself originates. Then we can have some extra
objects like effectors which basically affect the
flow of the simulation. We can have an effector that, for example, blocks the fluid. Let's say if we have
a fire simulation, then the fire just
bounces off fit and close in a different direction,
and that's what we need. Right here, in the
default scene, I'm going to delete
everything and then press sift and search
for U is sphere. Now press shift a again
and search for Q. And I'm to scale up this cube, press Control A, and
apply the scale. This step is really important. Otherwise, sometimes the
simulation just doesn't play. Right now, I can come into wireframe mode by
pressing shifts, and then make sure you
have the cube selected and come over to the physics
step and select fluid. Set the type to domain. Let this be gas, because we need a fire and
smoke simulation. This could have been a liquid, but we are not doing water
simulations right now. We are going to look at all
these settings later on. Right now, we don't need them. Now, come over to the sphere, press fluid again,
set the tie to flow. I'm just ping the floor
type B at smoke for now. We look at these parameters, but let's come over here
and play the simulation. As you can see,
there is some smoke rising over here
and as it rises, it is blocked by the domain. I cannot go outside
of the domain. Another thing I want to show you guys is the flow behavior. There are three types
of flow behavior, the geometry inflow and outflow. The geometry, all that's
going to happen is basically it's going to fake
the volume of the geometry, and it's going to use
that to calculate how much fluid has to come
out of that geometry. It basically calculates how much of that fluid the smoke or the liquid or the fires can
be held within the geometry. And that's a default option. If we send it to inflow, it will just use the geometry as the origin point
of the fluid, but it's just going
to keep adding more and more fluid
to the simulation. If we plate with the
flow bed to inflow, Now you will see that we
have a lot more smoke coming out and it's going to keep coming out till the
end of the simulation. Another thing we can have, let's press shift
and add a cube, move it up along the z axis
and rotate it a little bit. Let's set it to fluid, set this to flow, and
in the flow behavior, I will set it to outflow. Now let's play the simulation
and see what happens. Right now we are not
seeing anything special, but the smoke is just
blocked to the bottom half, and that is because
the resolution of the simulation is really low. But essentially
what this outflow does is that it
absorbs the smoke. It absorbs the fluid inside
the fluid simulation. If I set it right here, you can see a lot more
smoke coming out. But in this tiny part
right below the cube, as you can see, there's
a lot less work because that smoke is being
absorbed by the cube. Another thing I wanted
to show you guys is that we can send the fluid type to effector and move this down. Let's see what happens now. Now when we play the simulation, as you can see the
smoke is spreading out a lot more and it's
going around the cube. If we scale it, the effect is going to be a
lot more apparent. As you can see the cube is causing the smoke to spread out, and that's what effect does. It basically causes the
fluid to go around it. It's basically
like the real word equivalent of a
collision object. And now we can set the floor
type to fire plus smoke. We don't need to change
any more settings. Now if we play the simulation, we get a fire, but we
also get some smoke. There's also another
option called fire. We are not going to look
at fluid in this glass. But if we set it to fire and
play back as you can see, we get a lot more fire
and a lot less smoke. However, the difference between the floor type fire
and floor type fire. The smoke is much more
than the amount of smoke. So essentially what's
happening right here is when we're using
the floor type of fire, it's waiting for the fire
to die out and then it's going to change the fire
that dies out into smoke. Basically, it's a more
realistic behavior when the fire burns out, it leaves behind some smoke. Whereas with fire plus smoke, what happens is that it simulates fire and
smoke at the same time. It's generating the fire and it's generating
the smoke separately. There's going to be both and
they are not dependent on the quantity of one or the
other in the simulation. Now let's look at
some domain settings. If I come over here and
send the resolution to something like 64 and then
play the simulation back. Now you'll notice that
it takes a lot longer to simulate because we are simulating at a
higher resolution. But as you can see that the details in the
fire are better, and they're also reacting
to the collide better. That is because it's a way
more accurate simulation. Now, in order to just
make the simulation part better and not
focus on the quantity, I can set the
resolution back and instead set the time stems
to something like eight. Basically, it will calculate eight steps per
every single frame, and it will just make the physics part of the
simulation much better, but the stimulation will
still look pretty bare. We are going to look
at the other things right here in later tutorials. But right now, this is the brief introduction to fluid systems that I
wanted to give you guys. I hope you enjoyed the lecture
and in the next lecture, we'll start actually creating
our nuclear explosion. See you there.
3. 3) Making the explosion: Hello, everyone, and welcome back to another
tutorial lecture. In this lecture, we
are going to start creating a nuclear explosion. Right now, I'm going to delete everything we did in
the last tutorial. You can keep it as a
separate file if you want. Now I'm just going to
add an icophere right here and come over to a horizontal axis.
Oops, I messed it up. I'm just going to delete
it and add another sphere. And make sure that the
subdivisions which are by default two are
set to three instead. Now we can delete
the bottom half of the vertices because we only need the top half
of the io sphere, and this is going to be the
base of our nuclear exploor. Right here, I'm going
to come over to the modifiers and
search for display. Click a new texture, go over to the settings. Here I'm going to set
the tip to clouds. Then I can play around with the size to get
the thing I want. I'm also going to
silt the top vertex, turn on proportionally
editing by pressing O and then just bring
everything slightly down, and then love the
whole thing up. Like such because we want
a much flatter simulation. I can adjust the scale right
here to something I like. Let's just keep it
at that actually. Then over in the
particle system stab, I'm going to press plus, and that's going to
add a particle system. The reason we are doing this is because when we are doing
a nuclear explosion, we want something to drive
the direction of the fire. For that, we use a
particle system. Right now the particles
are falling straight down, which we obviously don't want. But right now, I'm
just going to set the number of
particles to 5,000, so we get a much
denser simulation. Then I'm going to set
the frame start to zero, frame to maybe 12, and light frame to five. Now in the velocity, I'm going to set the normal
velocity to around five, and then the z velocity
to five as well. Now the articles should
shoot straight up. Let's see, and yes, they are. Maybe the sphere
is a little big, so I'm going to press
S, and like such. I'm also going to
decrease the noise, scale it down on the z axis. This is giving us the
type of output we want. Also, you can see the particles
are of shooting off in a straight line or
multiple straight lines. What we can do is come back to the particle system and
increase the random ae. Now when we played back, the particle movement will
be a bit more random. As you can see, we no longer get those straight lines in
our particle system. That's about all we need to do with the particle
system right here. Now, what we will do is with
my sphere still selected, come over to frame zero
and go over to object, quick effects, and quick smoke. Now as you can see, we have a separate smoke stimulation
and our particle simulation. Now this is not exactly
what we want obviously. Come over to the physics tab, the flow behavior is
going to be in flow. Make sure initial velocity
is turned on, and then here, I'm going to set
the flow source to particle system and select
my particle system. Let's try playing this back. Now as you can see, instead
of just going straight up, our smoke is following the
direction of our particles. When the particles disappear, we can see the
smoke right there. A and now I'm going to set the floor type to fire plus smoke and let's
see what happens. This looks like an explosion. I'm going to scale it up on
the x axis and the z axis, and also come over to the horizontal axis
and move the domain up so that the particles do not escape from
below by any chance, and also scale it
up on the y axis. Now this is looking like
a nuclear explosion. Now what we want to do is set the resolution to
somewhere around 120, and I'm going to set
the frame to about, let's just keep
it at 80 for now. I only want to stimulate
for 80 frames. Now, this is really
slow for now. What I'm going to do is go over here and set
the time to all, which will allow me to
bake the simulation, and then we want to adjust
a few of the values. First of all, I'm going
to change the water city, which adjusts the number
of tours in the smoke. I'm going to send the border
collisions to bottom. You can also increase the
time steps if you want, which will make the
simulation more accurate, yeah, that's about it. Now I can come over here
and select Ba call. It's going to take
a while to bake. I didn't bake all of
it. I bake some of it. First of all, I want to disable the particle
system for now. Now as you can see, we have some of a nuclear explosion
going right here. You can always increase
the resolution of the stimulation to get a more
accurate fire and smoke. That's it for this tutorial. In the next lecture, we are going to
learn how to set up the EV renderer to
render this out, and then after that, we'll learn how to
render the same thing out using cycles. See you there.
4. 4) Eevee Rendering Setup: Hello, everyone, and
welcome to the class. In this lecture, we're
going to learn how to render out the
simulation in EV. Now, right now,
if I come over to EV and add a sky texture, you'll notice that the
simulation looks bad. First of all, come over to
the y axis and add a camera, and I'm going to best control all Numpat zero to
position the camera. Now what I'm going to
do is come over to the render settings, volumes, and set the resolution
to one is to one, which makes it look much better. We can also change
the custom range, set the start of the
range to where we can just see the explosion and set the end range to something like five or six steps after it. And now we can increase the
steps in the volumes to 128. We also need to add a
material to the domain. Come over here, and
the shader editor, make sure to turn up the
black body intensity. Now I know that this
still looks really bad. However, we are seeing
the simulation right now. The reason this is looking bad is because we need to follow some more steps which we learn in the cycles render tutorial, and that will help us in
the EV output as well. I will see you in the next
tutorial where we will learn how to create
a shader for cycles, and that shader is also
going to work in EV and increase the quality of
our output. See you there.
5. 5) Making The Bomb Material And Compositing: Hello, everyone.
In this necture, we are going to learn how to improve the look of our seal. As you can see right now, we are not seeing any of
the fire in our bond. Also the smoke is
very less dense, and to fix that, we
actually need to create a proper smoke
and fire material. To do that, first of all, come over to the smoke domain. And make sure you have a
principled volume material and a material output and make sure that the principled
volume is plug into the volume node and
not the surface node. That way we get
an actual volume. Now, right here, first of all, I'm going to increase the
density to somewhere around, which will make the
smoke more dense, and I can come over
to the color of the smoke and decrease
it to right around here. That way we get a blacker sob. We can also change
the sky texture if you want to see
it more clearly, but I'm just going to
keep it at what it was. The next thing we want is to
see the fire in our bomb. One thing we could
do is to just change the black body intensity
to something like Pi. Now, the fire is really dense, we are not seeing anything. To make the fire visible, what we need to do
is first of all, we need to shift and
search for volume info. And this node does exactly
what it sounds like. It gives the information about the volume
of the material. We have the color, the density, the flame, and the temperature. Then we can pull out the flame and search for a color ram. Then we can add a
converter match node. Make sure that you use
the converter math node and not the vector math node. This is very important.
Fl the color into the value and flu the value
into the emission stren. Now it looks weird right now, but if we change the ad to multiply This looks much better. Now we can change the
values from right here. This second value right here determines how much
fire we are going to see. If we change it to
somewhere around 50, nothing happens because
we made a mistake here, we didn't have to use the flame, we actually had to
use the density. As you can see, we can see
a lot of flames right here. I'm just going to pull
the filler back in. However, the flame
is white for now, and to adjust the
color of the flames. What we can do is again pull
out this density and add another color ramp and plum the color into
the eviion color. Now what we'll do is I'm going
to first take this color, the white color, and change it to somewhere around
light yellowish. Now, click the plus. I can move the color
to somewhere around here and main the
color a little darker. And then repeat the step a third time and this time it's
going to be much word. I think this looks really nice. The last thing I wanted to show you guys is some compositing. First of all, come over to these settings and
in viewport shading, make sure the composite is set to either camera or always. If you set it to camera, then you'll only
see the compositing in camera view while
in the viewport. When you render it out, you're going to always see
the compositing, but we are talking about
live compositing here. You can either set it
to camera or always. Otherwise, you won't see your composites until you
have rendered the scene. Now come over to
compositing right here. Make sure this use
nodes is changed, and then what we have
to do is pushed off, press shift filter, and drop in this glare
node right here. With back drop turned on, drag out this image and add a viewer so we can
see what's going on. Now we get some streak effect. I'm going to change it to regular blue and
decrease the size. That way we can see that the image has some
of a blue method. You can always change
the threshold or any other settings you want
to make this pit your liking. That's it for this class, I
really hope you enjoyed and learned something new and
see you in the next class.
Yash Kejriwal
