Flock operator

The Flock operator allows you to add boid-style flocking forces to particles.


Flock Forces

  • Neighbor alignment: when enabled, neighbor alignment forces will be computed.

  • Neighbor cohesion: when enabled, neighbor cohesion forces will be computed.

  • Neighbor repulsion: when enabled, neighbor repulsion forces will be computed.

Neighbor Alignment

  • Direction %: the percentage of cumulative neighbor direction each particle will adopt.

  • Velocity %: the percentage of cumulative neighbor velocity each particle will adopt.

  • Variation %: the per-particle percentage of variation to apply.
Neighbor influence

The neighbor influence extends outwards from the particle’s neighbors

  • Distance: particles within this distance will be fully affected.

  • Falloff: the effect on particles beyond the base distance, but within this falloff distance, will diminish according to the inverse-square law.


Relative to property

The relative property multiplier will adjust values based on the ratio between the value of a particle property and the specified threshold value.

  • Property type: the particle property to which the threshold value will be compared.

  • Threshold: the target value to which the selected property value of a particle will be compared.

  • Min multiplier: the minimum value of the resulting multiplier.

  • Max multiplier: the maximum value of the resulting multiplier.

  • Exponent: the exponent to which the ratio between the particle property and the selected property will be raised.


Neighbor Cohesion

  • Velocity: the velocity a particle will travel towards its neighbors.

  • Variation %: the per-particle percentage of variation to apply.
Neighbor influence

The neighbor influence extends outwards from the particle’s neighbors

  • Distance: particles within this distance will be fully affected.

  • Falloff: the effect on particles beyond the base distance, but within this falloff distance, will diminish according to the inverse-square law.


Neighbor Repulsion

  • Velocity: the velocity a particle will travel away from its neighbors.

  • Variation %: the per-particle percentage of variation to apply.
Neighbor influence

The neighbor influence extends outwards from the particle’s neighbors

  • Distance: particles within this distance will be fully affected.

  • Falloff: the effect on particles beyond the base distance, but within this falloff distance, will diminish according to the inverse-square law.


Relative to property

The relative property multiplier will adjust values based on the ratio between the value of a particle property and the specified threshold value.

  • Property type: the particle property to which the threshold value will be compared.

  • Threshold: the target value to which the selected property value of a particle will be compared.

  • Min multiplier: the minimum value of the resulting multiplier.

  • Max multiplier: the maximum value of the resulting multiplier.

  • Exponent: the exponent to which the ratio between the particle property and the selected property will be raised.


Simulation groups

  • Simulation groups: only neighbors with matching simulation groups will be considered.

Obstacles

  • Object list: the obstacle objects.

Proximity Avoidance

  • Direction %: the percentage of avoidance direction each particle will adopt.

  • Variation %: the per-particle percentage of variation to apply.
Proximity influence

The proximity influence extends outwards from the surface of nearby obstacles.

  • Distance: particles within this distance will be fully affected.

  • Falloff: the effect on particles beyond the base distance, but within this falloff distance, will diminish according to the inverse-square law.


Raycast Avoidance

  • Direction %: the percentage of avoidance direction each particle will adopt.

  • Variation %: the per-particle percentage of variation to apply.
Proximity influence

The proximity influence extends outwards from the surface of obstacles hit by raycasts.

  • Distance: particles within this distance will be fully affected.

  • Falloff: the effect on particles beyond the base distance, but within this falloff distance, will diminish according to the inverse-square law.


  • Ignore backfaces: rays that hit backfaces of obstacles will be ignored.