Random Seed
Sets the random seed so a procedural variation can be reproduced.
← Fusion node reference
ParticlesIntermediate
pGradientForce
Drive particles along a gradient
Pushes particles according to a gradient field with adjustable strength and the standard probability, age, set and region conditions.
pGradientForce
DaVinci Resolve · Fusion
pGradientForce turns a gradient into directional particle motion, allowing image-derived or procedural fields to steer a simulation.
Overview
What pGradientForce does
pGradientForce turns a gradient into directional particle motion, allowing image-derived or procedural fields to steer a simulation.
Mental model
Think of the gradient as a slope map: particles are pushed according to how that field changes across space.
Common uses
Steer particles with a procedural field
Create image-influenced particle flow
Add non-uniform directional motion
Restrict gradient forces to selected ages, sets or regions
Flow anatomy
Inputs & outputs
The port structure shows how this node fits into a Fusion graph.
Particles
Incoming particle stream from pEmitter, pImageEmitter, pMerge or another particle node.
Region
Optional region or mask that limits where the operation affects particles.
pGradientForce
Fusion node
Particles
Processed particle stream for additional particle tools or pRender.
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 how strongly the gradient affects particle motion.
Tip: Start low because force accumulates over time.
Probability
Limits the percentage of particles affected.
Age Start
Sets the particle-age range affected by this operation.
Particle age is measured over the particle lifetime; use the start and end values to limit where the behavior becomes active.
Age End
Sets the particle-age range affected by this operation.
Particle age is measured over the particle lifetime; use the start and end values to limit where the behavior becomes active.
Age Range
Defines the range over which this operation is active.
Set Mode
Selects the Set Mode used by pGradientForce.
Ignore Sets
Excludes Sets from the operation.
Set 1–32
Chooses which particle sets are affected by this operation.
Region Mode
Controls where the gradient force is active.
Ignore region
Excludes region from the operation.
When intersecting region
Applies the operation while particles intersect the region.
When inside region
Applies the operation while particles are inside the region.
When not intersecting region
Applies the operation while particles do not intersect the region.
When not inside region
Applies the operation while particles are outside the region.
When entering region
Triggers the operation when particles enter the region.
When leaving region
Triggers the operation when particles leave the region.
Region
Selects the particle region type.
Chooses the geometric region used by the particle operation.
All
Applies the particle operation across the full region or particle set.
Bezier
Uses a Bezier-shaped region for the particle operation.
Bitmap
Uses a bitmap-defined region for the particle operation.
Cube
Uses a cube-shaped region for the particle operation.
Line
Uses a line region for this particle operation.
Mesh
Uses a mesh-based region for the particle operation.
Rectangle
Uses a rectangular region for the particle operation.
Sphere
Uses a spherical region for the particle operation.
Practical setup
A reliable workflow
- 1
Create the particle stream and gradient source/field.
- 2
Insert pGradientForce in the particle chain.
- 3
Set Strength low and play the animation.
- 4
Tune the gradient/region before increasing force.
- 5
Use Sets or Age conditions for layered behavior.
Typical node chain
Particles→
pGradientForce→
pRender
Examples
Where this node fits in real work
Gradient-guided dust
Particles drift according to a soft field instead of one uniform direction.
pEmitterpGradientForcepTurbulencepRender
Selective field motion
Only one particle set reacts to the gradient.
pEmitterpGradientForcepRender
Troubleshooting
Common mistakes
Using excessive Strength and getting unstable acceleration.
Judging the force on a still frame instead of playback.
Using a noisy gradient when a smooth field is needed.
Forgetting that other force nodes combine with the gradient result.
Production notes
Practical tips
Build the gradient field cleanly before tuning particle strength.
Combine with pDirectionalForce for a base flow plus local gradient variation.
Use Time Lock when probability-based selection should remain stable.
Related nodes