VecFlow0.1.0
FlowsOperators

Spawn

Make new particles from each particle: a few as it arrives, or a stream while it's in the event, sent along the wire with its looks.

VecFlow 0.1.0

Make new particles from each one, sent along the wire. They start with its looks.

Add it
EventAdd OperatorBirthSpawn
Sends on
Along its wire: the new particles it makes.
Influence
Yes: it works only on particles whose value is above a half.

When to use it

  • A burst where something happens: drops that splash into bits as they hit (the Fountain), fireworks that pop.
  • A trail: a rocket leaving smoke particles behind it, sparks shedding embers.

Set it up

Spawn needs a wire to the event its new particles go to. That event says what they do: give them their own size, forces and a Delete.

A flow of 2 events. Rockets: Birth, Position, Speed, Gravity, Spawn, Delete; Spawn: 20/s sends to Trail. Trail: Scale, Drag, Delete.RocketsSpawn: 20/sBirth: 5 per frame from 1. Make new particles: some every frame, all at once, one on each vertex of an object's mesh (for cloth and ropes: bind them with Bind, Mesh Edges), one on each piece of it (to smash: glue them with Bind, Pieces), or the event's Liquid filling itBirth: 5 per frame from 1Position: Launcher, box. Place new particles in an object's box, on its surface or inside it, or along a curve (a tube round it)Position: Launcher, boxSpeed: 15 m/s. Set the speed of particles entering the event, along a direction (an object's own axes when given), or add it to how they comeSpeed: 15 m/sGravity: 9.81 m/s². Pull particles down, or any way you point itGravity: 9.81 m/s²Spawn: 20/s. Make new particles from each one, sent along the wire. They start with its looksSpawn: 20/sDelete: at 2 s. Remove particles at an age (since birth, or since entering this event), or at onceDelete: at 2 sInTrailScale: × 0.3. Set the size of particles entering the eventScale: × 0.3Drag: 2. Slow particles to the speed of the air, which moves with the windDrag: 2Delete: at 1 s. Remove particles at an age (since birth, or since entering this event), or at onceDelete: at 1 sIn
Rockets leave a trail: each makes 20 particles a second, which go to Trail, slow down and fade out.BirthForcesPhysicsLooksTests

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.

Count
50 to 100,000

How many in all, or for spawn, how many from each particle as it arrives.

Per Second
Keyframable
00 to 100

How many each particle makes per second while in the event.

Spread
Keyframable
2 m/s0 to 20

Random extra speed in any direction.

Inherit Motion
Keyframable
10 to 1

Share of the motion passed on: the surface's or curve's, or for spawn, the particle's.

InfluenceEmpty

One of the flow’s number values, to weigh it by, particle by particle. Empty for all of it, on all of them. See Influence.

Count makes that many from each particle as it enters the event: born there, or arriving along a wire. Per Second makes a stream from each while it's there. Use either, or both.

New particles start where their parent is, with Inherit Motion times its velocity (all of it at 1) and up to Spread more in any direction. They keep its looks: its scale, rotation, spin, colour, shape and values. The parent carries on as it was.

Works with

  • Any event can take the new particles; they're born into it, so its entering operators (Scale, Colour, Speed…) set them as they arrive.
  • Influence: only particles whose value is above a half spawn.
  • A particle a test above Spawn sends on that step doesn't spawn.

Problems you may see

Error

event: operator must send its new particles to another event

Its wire goes back into its own event. Wire it to another event.

Error

event: operator needs a wire to the event its new particles go to

Wire the operator's output to the event its new particles start in.

Errors stop a bake; warnings don’t. Every message is on the Messages page.

Position

Place new particles in an object's box, on its surface, inside it, or along a curve, a tube round it or a sweep from end to end.

Speed

Set how fast and which way particles go as they enter an event: along a direction, turned with an object, with a random spread, or added to how they came.

On this page

When to use itSet it upSettingsWorks withProblems you may seeRelated