Forces


Forces are used to apply additional behaviour to particles based on realistic physics. They can be applied globally to a scene, or only affect a specific cuboid region.

Multiple forces can be added to a single particle simulator. Forces can be added to a particle simulator using the icon to the right of the Forces group on the timeline or in the Controls panel.

All forces are affected by the particle mass property in Particle system -> Movement. Particles with greater mass will be less affected by forces.

General

Active - turns the force on and off.
Kill particles - particles will die when entering the force region.
Kill mobile emitters - mobile emitters will die when entering the force region.

Shape

Global - affects the entire scene. All particles will be affected regardless of position.
Cuboid - force only acts within a specified volume, defined by the cuboid. You can change the dimensions and transform the cuboid. The Mask option uses the cuboid as a mask, hiding any particles that pass inside the volume or behind it from the camera's point of view.

Type

There are several types of force.

Direction

Direction forces particles in a specific direction.

The strength and direction of this force can be adjusted and keyframed. By combining multiple direction forces you can simulate both gravity and wind in a single particle simulator.

Attraction

Attraction forces draw particles towards a point in 3D space. When using a global force, this is the value of the force's center property. With cuboids it is the center of the shape.

The strength of attraction forces can be adjusted.

Detraction

Detraction forces propel particles away from a point in 3D space. When using a global force, this is the value of the force's center property. With cuboids it is the center of the shape.

The strength of detraction forces can be adjusted.

Turbulence

Turbulence causes particles to randomly change direction.

Smooth - smoother movement causes particles to change direction in a gentler manner.
Seed - changes the random composition of the turbulence field.
Strength - adjusts the strength of turbulence.