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.
Set the speed of particles entering the event, along a direction (an object's own axes when given), or add it to how they come.
- Add it
- EventAdd OperatorForcesSpeed
- Sends on
- Nothing: it has no wire.
- Influence
- Yes: it does as much as a value says, particle by particle (0 none, 1 all of it).
When to use it
- Launching: send newly born particles up, out or along an emitter's axis.
- A kick on arrival: in an event particles are sent to, change how they go: a bounce, a burst outward. With Add, on top of how they came.
Speed acts once, as particles enter its event (born there or sent there). For a push every step, use a force: Gravity, Drag's wind, or Attract.
Set it up
Put Speed below the Birth, and above any Position on a surface:
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 way they go, along the world's axes, or the object's own axes when one is picked.
Add to the velocity they come with instead of setting it: leaving a goal or follow, that is its target's motion, so a burst goes with it.
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.
Speed times Direction is the velocity they get. Direction is up until you change it; it needn't be one long, but Speed reads best when it is. Spread adds a random speed of up to this much in any direction, so 0 sends every particle the same way and more fans them out.
Name an Object and the Direction is in its axes: up means the object's own Z, so turning the emitter turns the spray.
Add adds the velocity to the one particles come with instead of replacing it. Particles leaving a Goal or Follow Curve come with their target's motion, so Speed with Add in the next event makes a burst that goes with it.
Works with
- Above Position: on a surface, Position adds its Speed Out and Inherit Motion to the speed particles have. A Speed below it replaces them, and the editor warns.
- Influence: weighed by a value, a particle's velocity goes that share of the way from what it had to what Speed gives.
Problems you may see
The editor raises no problems of its own for Speed.