Field Affector
Updated: 17 Feb 2025
Allows particles to be affector by froces from a field.
Field Affector
Method #
This node samples velocities from a Field node and applies them to particles. This can be used to apply motions generated on a field, e.g. via a fluid solver, and apply them to a particle system so the particles move with the field. The magnitude of the velocity is controlled by the Velocity Scale attribute and modulated by a random value which is constant per particle and weighted by the Randomness attribute.
Optical Flow nodes can also be accepted to drive particles based on a video feed.
This node requires a Field or Optical Flow node to be connected via the Field input.
Parameters
These properties control the 3D transforms of the node. Transforms will generally be inherited by child nodes, although they can be ignored through the Inherit Transform Channels attributes.
Parameter Details Position X
The objects position along the local x-axis.
Position Y
The objects position along the local y-axis.
Position Z
The objects position along the local z-axis.
Rotation Heading
The objects rotation around the local y-axis.
Rotation Pitch
The objects rotation around the local x-axis.
Rotation Bank
The objects rotation around the local z-axis.
Scale X
The objects scale along the local x-axis.
Scale Y
The objects scale along the local y-axis.
Scale Z
The objects scale along the local z-axis.
Control the inheritance of the transforms from the parent.
Parameter Details Position
Toggle inheritance of the Position from the parent.
Rotation
Toggle inheritance of the Rotation from the parent.
Scale
Toggle inheritance of the Scale from the parent.
World Position Only
Inherit the world position from the parent only, rotation and scale will be ignored. Overrides above properties.
Inherit Time
Toggle inheritance of time from the parent.
These properties control the core behaviours of the node.
Parameter Details Velocity Scale
Scale the strength of the affectors velocity on the particles.
Randomness
How much randomness is added in the particles movement.
Life Effect Coeffs
How much the particles are affected by the affector at different stages of the particles life cycle. Values 1 and 2 are control points used to control a bezier curve between values 0 and 3.
Apply Mode
Select whether the field force are applied as simple velocities or continuous forces.
Inputs
These properties control the 3D transforms of the node. Transforms will generally be inherited by child nodes, although they can be ignored through the Inherit Transform Channels attributes.
| Parameter | Details |
|---|---|
| Position X | The objects position along the local x-axis. |
| Position Y | The objects position along the local y-axis. |
| Position Z | The objects position along the local z-axis. |
| Rotation Heading | The objects rotation around the local y-axis. |
| Rotation Pitch | The objects rotation around the local x-axis. |
| Rotation Bank | The objects rotation around the local z-axis. |
| Scale X | The objects scale along the local x-axis. |
| Scale Y | The objects scale along the local y-axis. |
| Scale Z | The objects scale along the local z-axis. |
Control the inheritance of the transforms from the parent.
| Parameter | Details |
|---|---|
| Position | Toggle inheritance of the Position from the parent. |
| Rotation | Toggle inheritance of the Rotation from the parent. |
| Scale | Toggle inheritance of the Scale from the parent. |
| World Position Only | Inherit the world position from the parent only, rotation and scale will be ignored. Overrides above properties. |
| Inherit Time | Toggle inheritance of time from the parent. |
These properties control the core behaviours of the node.
| Parameter | Details |
|---|---|
| Velocity Scale | Scale the strength of the affectors velocity on the particles. |
| Randomness | How much randomness is added in the particles movement. |
| Life Effect Coeffs | How much the particles are affected by the affector at different stages of the particles life cycle. Values 1 and 2 are control points used to control a bezier curve between values 0 and 3. |
| Apply Mode | Select whether the field force are applied as simple velocities or continuous forces. |
| Name | Description | Typical Input |
|---|---|---|
| Field Node | The field root node to use | Field 3D Root |
| Mask Node | Mask out areas that particles cannot spawn. | Image Plane |
| Affected Emitters | Choose which particle emitters can be affected by the affector. | Primitive Emitter |
| Procedural Falloff | Use the distance field from a procedural system to vary how strong the affector is. | Procedural Root |
| Transform Modifiers | Apply the transforms of another node to this node. | Null |
| Target Node | Modifiy the rotations of the node to always direct the z axis towards the input. | Null |
| Local Transform Override | Apply the transforms of another node to this node, relative to its parent. | Null |