Smoke Source
Particles give off smoke, heat and fuel into the flow's gas as they go: for plumes, trails, fire and explosions, saved as OpenVDB and shown as a volume.
Particles give off smoke, heat and fuel into the flow's gas as they go, which rises, swirls and burns as the Smoke settings in the sidebar say: for plumes, trails, fire and explosions. The bake saves the gas as OpenVDB frames, shown as a volume beside the particles.
- Add it
- EventAdd OperatorPhysicsSmoke Source
- Sends on
- Nothing: it has no wire.
- Influence
- No: a value can’t weigh it.
When to use it
Smoke and fire. The particles are the source: where they go, they fill the gas round them with smoke, heat and fuel. Born on a surface they make a fire on it; flung out in a burst they make an explosion; trailing behind a rocket they make its smoke.
The gas itself (how it rises, cools, burns and swirls) is set once for the simulation, in the sidebar's Smoke and Fire panel, which shows when the flow has a Smoke Source.
Set it up
The quickest way is a starter: Fire, Smoke, Explosion, or Set on Fire for a mesh. They're flows like this:
The particles usually live a fraction of a second: they only need to put gas into the air. The bake saves the gas as OpenVDB frames, shown as a volume object, “name Smoke”, beside the particles.
Settings
As the flow editor’s sidebar shows them. Changing any of them marks the bake old; none of them can change through a bake.
Fuel it gives off, which burns where it's hot enough, making flame, heat, smoke and a push outward (the flow's Fire settings). 0 for plain smoke.
How it fills the gas around it.
- Up To: The gas round it is filled up to Smoke, Heat and Fuel, never past them.
- Add: Smoke, Heat and Fuel are added each second, so the gas round a source that stays put keeps building up: dense, hot cores that burst into fireballs. Not with NVIDIA Flow.
How much what it gives off varies through the gas, by a noise that drifts: patchy, lumpy sources instead of even balls. Not with NVIDIA Flow.
Where the gas it gives off gets its colour.
- None: No colour: the gas stays white, or goes as the Smoke and Fire panel's Gas Colour says.
- Own: The gas it gives off takes this colour, and mixes with the colours of others.
- Particle's: The gas each particle gives off takes the particle's own colour, from a Colour operator before this one. Not with NVIDIA Flow.
Each particle fills the gas cells within Radius of it (times its scale) up to Smoke, Heat and Fuel. Heat makes the gas rise. Fuel burns where the gas is hot enough, making flames, more heat, smoke and a push outward: with 0 it's plain smoke. Push drags the gas round each particle along with it, so fast particles stir the air: 0 leaves the gas alone, 1 takes it all the way.
Fill says how: Up To fills the gas up to those amounts and never past them; Add gives them each second, so where a source stays put the gas keeps building up, into the dense, hot cores that burst into fireballs. With Add the amounts are per second, so they want to be bigger than with Up To. Variation makes what it gives off patchy, by a noise that drifts through the gas, Variation Size cells across: lumpy, uneven sources instead of smooth balls. Add and Variation are for VecFlow's own gas solver; NVIDIA Flow fills up to the amounts, evenly.
Colour gives the gas a colour of its own, for coloured smoke and chemical flames: Own gives it Gas Colour, Particle's each particle's own colour (from a Colour operator before it). The gas carries the colour as it goes, and where gas of two colours meets, it mixes, by how much of each there is. A cell takes a source's colour by the share of its smoke, heat and fuel the source just gave it, so a source sitting in gas it already filled leaves its colour as it is until the gas moves on. None leaves the gas white. The material then colours the flames and smoke by it (see the flame's look), and the Smoke and Fire panel's Gas Colour can change it as the gas goes. Not with NVIDIA Flow.
Works with
- Speed, Turbulence and Drag: how the particles move is how the source moves.
- Delete: short lives keep the source near where they're born.
- Smoke Sources in several events all feed the one gas: give each its own Colour for flames of several colours.
- Smoke Force: particles of another event carried by the gas, for sparks and embers.
Problems you may see
… reads the flow's gas: add a Smoke Source to make it
Errors stop a bake; warnings don’t. Every message is on the Messages page.