Velocity Behavior
This behavior affects particle velocity over time. It can be used to gradually dampen the starting velocity through friction or to control the particle speed using a curve.
Friction: This value imitates air friction. If it is non-zero, the particle's velocity will be dampened over time. The value's range is [0; infinity]. To achieve an effect as in the animation below, the particles must have a very large starting velocity (here: 10). The friction here is set to 6. This way the particles will appear to be quite fast, but will also get slowed down almost to a standstill within a fraction of a second.
SpeedCurve: A curve that controls the particle speed over its lifetime. This allows for more precise control over how fast particles move at different stages of their life.