Whitewater
The liquid makes spray, foam and bubbles where it crashes or crests, each sent along its own wire to an event that says how long it lasts.
The liquid makes spray, foam and bubbles where it crashes into itself or crests fast, each sent along its wire to an event of its own (to show as small points, and delete after a while). Spray flies as its event's operators say, foam rides the surface, bubbles rise through the liquid. A kind with no wire isn't made. Fast spray can turn to mist, which drifts with the air.
- Add it
- EventAdd OperatorPhysicsWhitewater
- Sends on
- 4 wires, Spray, Foam, Bubbles, Mist: each kind goes to an event of its own. A kind with no wire isn’t made.
- Influence
- No: a value can’t weigh it.
When to use it
Big water: a dam breaking, waves crashing, a splash, a waterfall. Where the liquid crashes into itself or crests fast, it makes small particles of three kinds:
- Spray flies off, as its own event's operators say.
- Foam rides the surface.
- Bubbles rise through the liquid.
Each becomes another kind as the liquid round it thins or thickens.
Set it up
Put Whitewater in the same event as the Liquid, and wire each kind you want to an event of its own. A kind with no wire isn't made. Give each event a Delete by age Since Birth, so whitewater doesn't pile up; spray needs Gravity too.
Settings
As the flow editor’s sidebar shows them. Changing any of them marks the bake old; those marked Keyframable can also change through a bake.
The most new particles each liquid particle makes a second, where it crashes or crests hardest.
How fast the liquid must go to make any: from half this, the most at this. Lower for gentle scenes, higher for big ones.
Whitewater made under the surface is born a bubble, and a bubble stays one until it leaves the water: against the glass or an object the water reads thin, so bubbles there turned to foam and stopped rising. Off keeps older bakes as they were.
Rate is the most each liquid particle makes a second, where it crashes or crests hardest. Speed is how fast the liquid must go to make any: from half this, the most at this. Lower it for gentle scenes, raise it for big ones, or a calm surface fizzes.
Each particle is sorted by how much liquid is round it: little, spray; some, foam; nearly all, a bubble. Against a wall or an object the liquid reads thin (it stands off a solid by most of a spacing), so bubbles there turned to foam and stopped rising. With Keep Bubbles, whitewater made under the surface is born a bubble and stays one until it leaves the water, so the trail of bubbles on an object plunging through the water rises as it should. With it, whitewater is also only made near the surface, a pocket of trapped air or the cavity behind an object, where there is air to trap: the jolt of an impact runs down the whole column, and at a fine spacing it would otherwise seed bubbles metres from any air. It is off so older bakes stay as they were; turn it on for new scenes with objects in the water.
How it looks
Whitewater shows as many tiny points, as studios render it, not as balls: see Whitewater as Foam in the Liquid panel. There each kind has its own number of points, size and spread, and Fade Out shrinks them before their event's Delete takes them, so none pops out (it reads the Delete's age since birth). Foam on Water turns the water's surface milky where foam lies on it. None of it needs a new bake.
Works with
- A Liquid in the same event: whitewater comes from it, and is made inside its walls.
- Delete in each kind's event.
- An event takes one Whitewater. It sends to other events than its liquid's.
Problems you may see
event: operator comes from the event's liquid: add a Liquid
event: operator needs a wire from Spray, Foam or Bubbles to an event
event: operator sends to other events than its liquid's
event: operator: an event takes only one
event: operator: mist comes from spray: wire Spray too
Errors stop a bake; warnings don’t. Every message is on the Messages page.
Related
Liquid
Make particles a liquid that keeps its volume: it pours, splashes and fills, floats rigid bodies and pushes cloth, with a surface mesh made by the bake.
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.