Force Field
Generate a directional (wind or gravity), point, vortex, turbulence, or drag force field.
What it does
Generates a force for a physics simulation: wind, a gravity-like pull, a spinning vortex, gusty turbulence or velocity drag. Pick a Force Type, then set direction, strength and where in space it takes hold. The output plugs into Physics World's Forces input, which accepts more than one Force Field at a time, so forces can be layered.
Position and Radius keep a force local, a gust near one spot or an attractor pulling objects toward a point, rather than applying it to the whole scene. Falloff shapes how the force fades toward the edge of that radius.
When to use it
A constant wind or gravity push: Directional
Objects pulled toward or pushed away from a point: Point, with the sign of Strength flipped to invert it
Whirlpool or cyclone motion around an axis: Vortex
Gusty, organic motion: Turbulence, or Noise Amplitude on Directional
Moving objects slowing over time: Drag
A force confined to a local area: set a Radius and a Falloff curve
| Parameter | Type | Default |
|---|---|---|
force_type | String | "Directional" |
direction_x | Number | 1 |
direction_y | Number | 0 |
direction_z | Number | 0 |
strength | Number | 50 |
position_x | Number | 0 |
position_y | Number | 0 |
position_z | Number | 0 |
radius | Number | 0 |
falloff | String | "None" |
noise_amplitude | Number | 0 |
noise_frequency | Number | 0.010 |
noise_speed | Number | 1 |
Gotchas
For a Point force, a negative Strength inverts the pull into a push, so one knob covers attractor and repulsor.
Radius defaults to 0, which means the force reaches everywhere with no falloff. Set a radius before Falloff does anything.
Direction applies to Directional and Vortex only, and for Vortex it sets the spin axis. Noise applies to Directional and Turbulence only. Point and Drag hide those groups, because they do not use them.
Worked example
Add a Force Field and wire its output into Physics World's Forces input.
Set Force Type to Directional, then set Direction and Strength for a steady wind.
Give it a Position and Radius so the wind only affects one region, and pick a Falloff so it fades smoothly at the edge.
Raise Noise Amplitude and Noise Frequency for gusty variation, and Noise Speed to control how fast the gusts shift over time.