Welcome to the quick start tutorial for
Fenix FD4 3DS Max. In this video, we
look at creating a liquid simulation
first using a quick preset and then
we'll rebuild it manually to more fully
understand it. Now, I'll start in a
blank scene and I'll create a sphere and
place it here. This will be the source
of my liquid. With the sphere still
selected, choose the tap water preset
from the Fenix FD toolbar. Now select
the start simulation icon and you'll see
the liquid simulation begin pouring down
from the
sphere. Click stop to halt the
simulation as it starts to fill the
container. Okay, let's add a dome light
from the V-Ray toolbar to the scene. And
in the command panel, set the dome light
to be invisible. Make sure you're set to
V-Ray as your renderer and then render
the frame to have a look at your quick
preset water
simulation. Now, we did that pretty
easily by using the tap water preset.
So, let's take a look at setting this up
manually to have more
control. Select the liquid simulator and
delete it. And then select the source
and delete that as well to start fresh.
Click on the create a liquid simulator
icon in the Fenix FD toolbar and click
and drag to create a volume like
so. Make sure the sphere is inside the
simulator and is at the top. Now click
create a liquid source icon in the
toolbar and place the source in your
scene. In the modify panel, you can see
that there is no emitter for this source
yet. So click the add button and select
the sphere to add that to the emitter
nodes list. Now it's very important to
note that scale is a central factor in
simulations. Our sphere is about 4.5 cm
wide. So I'll just set that radius to an
even 4 cm. Since size is an important
factor, make sure to build your scene in
realworld units. So, it's a good idea to
go into the unit setup in the customize
menu to check your settings and make
sure that your units
match. Select the simulator and in the
modify panel under the grid rollout are
the parameters to control the resolution
of your grid which greatly affects the
look and performance of the sim.
Increasing the cell size reduces the
overall resolution of the simulation
shown in total cells parameter which
gives you better
performance. Decreasing cell size
increases the resolution making the sim
look and act better but at the cost of
system performance. So it's always a
good idea to go for the lowest total
cells possible that give you the look
you need to maximize performance.
I'll set the cell size to about.3 cm,
giving me about 4 million cells. When
you use a quick preset, this parameter
is adjusted for you. Now, if you click
the start simulation icon, you'll
confirm that the sphere is emitting the
liquid inside the
simulator. This time, the sim is all
white compared to the quick preset. So,
let's go ahead and change that. Select
the simulator and expand the preview
roll out. The faster the particles are,
the whiter they will be. So, we will
offset the white speed parameter by
making it higher. Introducing blue into
the sim where the particles are not
traveling as fast as this value. Set the
white speed to
1200. Now, let's get this to look more
like what we had with the preset. Right
now, the edges of the pore are pretty
jagged. Expand the dynamics roll out and
adjust the steps per frame to 12. This
provides for a more natural look, but
will make the sim run slower. The higher
the steps per frame, the longer the
calculations, so try to find the low
setting for the effect that you
need. And after letting the simulation
run a bit, moving up to 12 for steps per
frame did address this ragged edge
effect and helped smooth the shape of
the pore.
As you can see, the liquid is flowing
right through the floor and
disappearing. This means that our
simulator is open and needs to be
closed. Open the grid roll out. You can
see the boundary conditions are indeed
all open. Set the X, Y, and Z axes to
jammed both. As the simulation runs, the
liquid will now collide with the bottom
and the sidewalls of the simulation
container. It is however running slowly.
So we can adjust the resolution to
address that. First take note that we
have about 4.4 million cells to
calculate in the sim and click decrease
resolution to have the number of total
cells to make the sim run faster. Stop
the sim and click decrease resolution
two more times to get about half a
million cells. You can also set the cell
size parameter directly to affect the
resolution. Put in.5 cm for the cell
size and we'll end up with just about
900,000 total cells. Start the sim again
and you'll see it's running much
faster. Click to the dynamics roll out
and set the steps per frame to one to
speed up the sim even more. Now, feel
free to experiment with different
settings. And when you're done, go ahead
and stop your sim. Render the result.
And you'll notice that the water is a
solid purple color. Open the slate
material editor and drag in a new V-Ray
material. Double click it to see its
parameters and set the diffuse to black.
Then set both reflect and refract to
white. And then enter an IR value of
1.33 for water. Now you simply assign
the selected material to the simulator
and we should get a better water look
when you render a new frame. Now of
course feel free to adjust the material
and the lighting in the scene to achieve
the look that you're going for. Now
let's look at how to make this liquid
collide with and fill an actual object
rather than just the simulator's box
shape. Here I have a scene with a jar in
the studio lighting setup with a
background. This file is provided in the
tutorials downloaded assets shown below.
Switch your view to Fizz Cam 001 to see
what we'll be rendering. Back to
perspective view and select the sphere.
In the Fenix FD toolbar, choose the tap
water quick preset just like we did
before. It creates the simulator, but we
need to adjust it. Use the X, Y, and Z
size parameters to size the simulator
shape to have a little space between it
and the jar. And then move the container
down around the jar like so. Using these
parameters to size the container as
opposed to simply scaling the simulator
also changes the simulator's resolution
to give it more detail as needed in
larger containers. And this is the best
way to size one of these containers.
Start the simulation. I'll elapse some
time here to show you how the sim
resolves over the course of several
minutes. Go back to your camera view.
Open the slate to create a material for
the water. Create a V-Ray material just
like we did in the last part of the
tutorial. Make sure the diffuse is
black, that reflection and refraction
are both white, and that you set the IR
to
1.33. Create another V-Ray material for
the glass jar. Make sure you set the
diffuse to black and reflection and
refraction are both white, but this time
leave the IUR to
1.6. Select the glass part of the jar
and assign this material. Render a frame
to see how the fluid is interacting with
the jar. Any geometry inside a
simulation container will automatically
interact with the emitting fluid. You
can of course exclude geometry from
interacting. And you can even create
nonsolid geometries which are geometries
that a simulation can flow through but
still be used as a source or a force
acting on that simulation.
These we will discuss in upcoming
videos. Now the sim will eventually
overflow the jar. So select the liquid
source object and look at the outgoing
velocity parameter. This sets how much
fluid is being discharged by the
emitter. And so animating this value
will control how much liquid is being
created like when you need to start and
stop the pour. Select the simulator and
click the decrease resolution button
three times to have a resolution of
about 1.6 million cells. Scrub your
timeline back to the start. Now, we're
going to be animating the port to look
like this rendered
result. So, at the beginning of the
scene, select the source and set the
outgoing velocity to zero, meaning
nothing will be emitted even if you
start the
simulation. Now set the outgoing
velocity to 16 and then scrub ahead to
frame 23 and then click the auto key
button to turn it on. Enter zero for
outgoing velocity at frame 23. So now
our outgoing velocity is keyed at 16 at
frame zero. And I'll click and drag that
key frame over to frame 20 so that the
liquid stops pouring between frame 20
and
23. Turn off auto key. go back to the
beginning and start the sim. I'll elapse
time here again to show how the
simulation resolves over several minutes
and then I'll stop the
simulation. Scrub the simulation and
it's a little choppy. So select the
simulator and in the preview roll out
turn off show mesh. This now just shows
the particles for the liquid pore and
will scrub much faster. You can pick a
point in the simulation like I will here
and turn show mesh back on to see the
liquid
better. You can see at the top of the
pore there's a large spread of these
drops coming out of the emitter. This is
because the emission is coming from the
surface of the sphere. Select the liquid
source object and change the emit mode
to volume brush. What this means is that
instead of emitting the liquid from the
surface area of the sphere, it will now
emit from the whole volume of the
sphere. Now a dialogue appears asking to
convert the emitter to a non-solid
object. So choose yes. This means that
the sphere geometry itself will not
interact with the liquid simulation,
sort of like holding a ball under
pouring water. Select the simulator and
in the modify panel under the dynamics
roll out reduce steps per frame to five.
Go to the start of the timeline and
start the simulation. Now I'll elapse a
little time here to let the simulation
calculate for just a couple of minutes
and then I'll stop the sim here to show
you how those spread out droplets are no
longer an
issue. Go back to the camera view and
render a frame to see how the jar looks
now.
After a brief moment, you should have a
nice jar of water just like this. Thank
you for joining us on this quick start
video on liquid simulations using Fenix
FD for 3ds Max.