Trapcode Particular

Flocking

Flocking affects how particles behave and interact with each other in the group, or with particles in other systems. Particles move with an awareness of each other. They can be attracted, or repelled by one another. They can move towards the same goals or targets.

Turn on Enable Flocking to activate the Flocking Simulation.

Attract

defines the particle’s tendency to move towards the center of the group.

Separate

controls the tendency of particles to push apart at very close proximity to each other, almost like a spring is attached to each particle blocking it from another.

Align

controls the tendency of any given particle to orient along with particles nearby, such as a flock of birds or a school of fish. For more randomness to the individual direction, like in a swarm of insects, this can be left at a lower number.

Predator/Prey Behavior

sets up the relationships between Systems:

• When set up as Prey, Evade lets you control how much they want to avoid a Predator
• If that system is set to Predator, Pursue controls how hungry it is
• On Predator/Prey Contact - Available when a particle system is identified as predator. When a predator particle system comes into contact with particles from a prey system we now have 5 events to choose from. These events are:
  • Do Nothing - When individual predator particles come into contact (touch) individual prey particles, nothing happens. The prey particles are still influenced by all the original properties set in the various sections/blocks
  • Kill Prey - When individual predator particles come into contact (touch) individual prey particles, the prey particles will die (vanish). In other words, the particles influenced original lifespan becomes overwritten.
  
  
  The blue predator particles are set to kill the white grid particles
  
  • Kill Both - When individual predator particles come into contact (touch) individual prey particles, the predator and prey particles will die (vanish) . In other words, the particles that are influenced original lifespan becomes overwritten.
  • Freeze Prey - When individual predator particles come into contact (touch) with individual prey particles, the prey particles will no longer have any motion; they'll become static. All speed or environment influences will no longer have influence on the affected prey particles.
  • Convert Prey to Predator - When individual predator particles come into contact (touch) with individual prey particles, the prey particles will change to whatever the predator particle is. For instance, if the Predator particle is a purple cell sprite and the prey a blue cell sprite, the blue cell (prey) will change to a purple cell (predator)
  
  
  The blue predator particles are set to kill the white grid particles
  • Team - Available when a particle system is identified as a predator or prey behavior. You can assign a particle system to be part of one of 4 teams (A, B, C or D). This is good to use when you want a predator system involved in a simulation with several other prey systems and you want the predator system to only attack specific prey systems and ignore others. By assigning a predator and prey system to the same team, the predator will not attack that prey system. It will only attack prey from different teams or prey not assigned to any team.
  • In the below example, the blue particles are from Team A and the red from Team B. The moving particles are predator systems and the static ones are prey. The blue predator particles only attack red prey particles and vice versa because of their team assignments, Without Team, the red and blue predator particles would attack all the prey particles.
  
  
• Maximum Speed limits how fast they each will travel
• Range of View is the distance (in pixels) across your composite that the particles can see
• Range of View Falloff adds a feather to that Range of View distance to control how quickly they snap to awareness
• Field of View is the angle of sight that your particle has. So for instance, you can simulate a predator that has eyes on the front of its head with 180 degrees, chasing prey that have eyes on the side of their heads and can see for an angle of 270 degrees.

Target

Particles can also be driven to a Target location/path:

• Set a point for the Target Position (which can be animated)
• then dial in the amount of Target Attraction the particles have. At 0%, they are not drawn to the target at all, whereas at 100% that is all they want to get to.
• Maximum Speed controls how fast they are able to get there.
• Range of View is the distance (in pixels) across your composite that the particles can see. If the target is outside of this range, they won’t be attracted to it because they do not notice it.
• Range of View Falloff adds a feather to that Range of View distance to control how quickly they snap to awareness

These controls can be mixed and matched for a huge variety of uses. For example, here’s a grid set with ‘Prey’ Evade turned up, meaning they will get out of the way when a ‘Predator’ particle passes by them.