In this video, we're going to be looking at the Billowy Smoke Tool in the Pyro FX shelf set.
You can find it on the top shelf under the Pyro FX tab.
We'll just start off by making a sphere as our smoke emission source object.
Double-click to go inside. We're going to change the shape of our emitter object.
We're also going to put down a rigid body ground plane so that our smoke can interact with a ground floor.
We'll turn off visibility on the ground plane, as well as the grid, since we don't need to see them.
Now hit the D key and we're going to change the background to "Dark" so that we can better see the smoke.
Hit the D key to close the window,
and let's go to our Billowy Smoke tool!
Click on it and select the sphere object and hit the ENTER key.
Right - so Houdini has turned our sphere object into a puff of smoke,
and here is the pyro node network that was created for us.
Let's jump back up to object level. We're going to change some parameters of our sphere surface.
In the create_density_volume node, we'll change a few things that will alter the shape of our smoke emissions.
We're going to turn off Minimum Distance and Empty Interior, so that we can use the full volume of our object to emit smoke.
Put down a value of 0.1 for Edge Location...
And in the Noise tab, we'll change Sharpness to 1,
and Element Size to 2.
Go back up to object level...
and we're almost ready to play it back!
Turn first on Realtime Playback. Double-click on the AutoDopNetwork...
and click on the pyrosolver node.
We're going to enable use OpenCL because the card that was used to create this video supports it.
Go back up to object level and hit the UP arrow key to play it back...
So we should probably put down a light, as it will help us to see the smoke better.
Click on the Lock button to position the light...
and uncheck it when we've finished...
Ok - now let's go to the AutoDopNetwork.
Hit the L key to organize your nodes and double-click on it!
In the pyro node, under Guides tab, click on Multi and change Density Scale to 20.
And in the Display Options window, go to Texture tab and uncheck Limit Resolution.
Be warned though that this may slow down performance depending on your rig.
You can also increase the resolution and limit it to that as well.
We're also going to increase the resolution of the smoke. Change the Division size to 0.05,
and note that the smaller the value, the higher the resolution.
But be warned that this will increase sim time.
Now let's go back to frame 1 and back up to object level and play it back!
OK, let's stop it and take a look at this container clipping here.
So as you can see, you have to be mindful of the size of your container because of the speed at which your smoke is traveling (in this case).
Double click on the AutoDopNetwork and in the resize_container node, increase the Padding amount.
And we can also change the actual container size in the pyro node.
Let's go back to frame 1 to refresh it,
and we can also manually adjust it if we want to as well.
So with your container selected, click on the Handle tool.
And then click on the red arrows to adjust it manually.
So here are the container parameters that we've settled on.
And let's have a look at our smoke!
So I've sped up the video here,
and we're just using this as a preview to make sure that smoke doesn't get clipped at our present container size.
And it doesn't!
So let's up the resolution.
Change the Division Size to 0.02.
And we'll let Houdini just update that change.
And now let's go back up to object level...
And we can make a flipbook preview to see what our smoke will look like.
And you can hit CTRL + B to maximize your 3D viewport window,
and click Accept.
But we'll just take a look at a premade flipbook preview instead.
So that's the Billowy Smoke tool from the Pyro FX Shelf set inside Houdini!