Method

This node gives the affected particles a fluid-like motion. This is typically used to make particles move in a turbulent but spatially coherent manner with local eddies like smoke or liquid. The motion is generated procedurally using Curl Noise rather than simulated so it doesn’t incur the performance overhead of a fluid solver.

The Curl Noise Amount attribute modulates the magnitude of the effect. The Noise Size attribute controls the tightness of the eddies.

The effect is weighted by a falloff calculated using the distance from the node to the particle, ramping from 100% at distance zero down to 0% at the distance specified by the Radius attribute.

Example
This image is taken from the “smokebox002.dfx” sample project.
Example Nodegraph

Transform

Name Description
Position X Move its position along the x-axis in local space.
Position Y Move its position along the y-axis in local space.
Position Z Move its position along the z-axis in local space.
Rotation Heading Rotate the object about the x-axis.
Rotation Pitch Rotate the object about the y-axis.
Rotation Bank Rotate the object about the z-axis.
Scale X Scale along the x-axis.
Scale Y Scale along the y-axis.
Scale Z Scale along the z-axis.

Inherit Transform Channels

Toggle which transform channels should be inherited. By default, all are on.

Attributes

Name Description
Fluid Simulation Speed Speed at which the fluid simulation updates.
Curl Noise Amount Controls the magnitude of the motion applied to the particles.
Noise Size Controls the size of the noise curls.
Normalise Noise Parameters Automatically balance the curl noise amount when the noise size changes.
Radius Alter the outer radius at which the affector is no longer effective.
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.

Inputs

Name Description Typical Node Input
Velocity Transform Can be used to apply an additional transform to the velocities generated by the node. Null
Mask Node Mask out areas that particles cannot spawn. Image Plane
Affected Emitters Choose which emitters can be affected by the affector. Primitive Emitter
Procedural Falloff Use the SDF values from a procedural system to dictate the falloff. Procedural Root
Transform Modifier Links all transform properties to the input node. Null
Target Node Always faces the x-axis towards the inputs anchor point. Null
Local Transform Override Override the transformation values of the node, relative to its parent. Null

Outputs

All nodes connected to this node are treated as if flowing to the parent node, and inherits any transformation changes along the chain.