Random Seed
Sets the random seed so a procedural variation can be reproduced.
← Fusion node reference
ParticlesIntermediate
pDirectionalForce
Push particles in one direction
Applies a constant directional force to particles, useful for wind, gravity-like drift, sparks and directed motion.
pDirectionalForce
DaVinci Resolve · Fusion
pDirectionalForce changes the velocity of an existing particle stream instead of generating particles itself.
Overview
What pDirectionalForce does
Strength controls how strongly the field changes particle motion, while Direction and Direction Z determine the force vector.
Probability, age ranges, sets and regions can restrict which particles are affected. This makes the node useful for localized or staged motion changes.
The node often works well together with pTurbulence: directional force establishes the overall flow, while turbulence removes mechanical uniformity.
Mental model
Think of pDirectionalForce as a steady fan blowing through the particle system.
Common uses
Wind-blown dust
Push sparks in a chosen direction
Simulate falling or drifting motion
Move particles through a scene
Create a base flow before turbulence
Flow anatomy
Inputs & outputs
The port structure shows how this node fits into a Fusion graph.
Particles
The incoming particle stream to be pushed.
Region
Input used by pDirectionalForce.
pDirectionalForce
Fusion node
Particles
The particle stream after directional force is applied.
Inspector
Important parameters
Start with these controls before reaching for more complicated workarounds.
Reseed
Sets the random seed so a procedural variation can be reproduced.
Time Lock
Locks procedural randomness to time so the same frame evaluates consistently.
Strength
Controls force magnitude.
Direction
Sets the main 2D direction of the force.
Direction Z
Adds force along the Z axis.
Probability
Controls what fraction of eligible particles are affected.
Age Start / End
Limits the force to a portion of particle life.
Set Mode
Selects the Set Mode used by pDirectionalForce.
Sets 1–32
Chooses which particle sets are affected by this operation.
Region Mode
Selects the particle region type.
Chooses the geometric region used by the particle operation. Available region types include Ignore region, When intersecting region, When inside region, When not intersecting region, When not inside region, When entering region, and When leaving region.
Region
Selects the particle region type.
Chooses the geometric region used by the particle operation. Available region types include All, Bezier, Bitmap, Cube, Line, Mesh, and Rectangle.
Practical setup
A reliable workflow
- 1
Create particles with pEmitter or pImageEmitter.
- 2
Connect pDirectionalForce after the emitter.
- 3
Set Strength and direction.
- 4
Add turbulence if the motion feels too uniform.
- 5
Render the result through pRender.
Typical node chain
pEmitter→
pDirectionalForce→
pTurbulence→
pRender
Examples
Where this node fits in real work
Windy sparks
Directional motion plus turbulence creates an organic spark stream.
pEmitterpDirectionalForcepTurbulencepRender
Localized push
Use a region so particles change direction only in one area.
pEmitterpDirectionalForcepRender
Troubleshooting
Common mistakes
Expecting the node to create particles.
Using excessive strength and causing particles to leave the frame immediately.
Forgetting that region/age filters can make the force appear inactive.
Production notes
Practical tips
Set the broad motion direction first, then add turbulence.
Animate Strength for gusts instead of keyframing emitter velocity.
Use regions when one field should affect only part of the scene.
Related nodes