Random Seed
Sets the random seed so a procedural variation can be reproduced.
← Fusion node reference
ParticlesIntermediate
pBounce
Particle collision and rebound
Makes particles collide with a defined region and rebound with configurable elasticity, roughness, spin and surface motion.
pBounce
DaVinci Resolve · Fusion
pBounce adds collision-like behavior to classic Fusion particle systems by treating a region as a surface.
Overview
What pBounce does
The region can represent a line, rectangle, sphere, bitmap, mesh or another supported shape. Particles that intersect it can change velocity as if they struck a physical surface.
Elasticity controls how much speed is preserved in the bounce. Roughness and variance prevent every collision from reflecting in exactly the same direction.
Surface Motion can transfer motion from the collision surface to particles, while age, probability and set controls determine which particles participate.
Mental model
Think of pBounce as an invisible collision surface with adjustable material properties: particles hit it, lose or preserve energy, and leave in a new direction.
Common uses
Bouncing sparks
Confetti hitting a floor
Particle collisions with spheres or rectangles
Stylized debris rebound
Create boundary interactions in a particle scene
Flow anatomy
Inputs & outputs
The port structure shows how this node fits into a Fusion graph.
Particles
Particle stream processed by this node.
Region / Mask / Geometry
Input used by pBounce.
pBounce
Fusion node
Particles
The processed particle stream.
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.
Elasticity
Controls how much velocity is retained after a collision.
Variance
Adds randomness to bounce behavior.
Spin
Adds or modifies particle rotation during collision.
Roughness
Makes the reflection less perfectly smooth.
Surface Motion
Transfers motion from the collision surface.
Surface Motion Direction
Sets the direction of the moving collision surface.
Probability
Controls what fraction of eligible collisions are applied.
Age Start / End
Limits collision behavior by particle age.
Set Mode
Selects the Set Mode used by pBounce.
Set 1–32
Chooses which particle sets are affected by this operation.
Region
Defines the collision surface and its shape.
Region: All
Uses All as the active region.
Region: Bezier
Uses Bezier as the active region.
Region: Bitmap
Uses Bitmap as the active region.
Region: Cube
Uses Cube as the active region.
Region: Line
Uses Line as the active region.
Region: Mesh
Uses Mesh as the active region.
Region: Rectangle
Uses Rectangle as the active region.
Region: Sphere
Uses Sphere as the active region.
Start Pick
Lets you place the collision region’s start point directly in the Viewer.
Start X/Y/Z Offset
Sets the X, Y and Z components of start.
End Pick
Lets you place the collision region’s end point directly in the Viewer.
End X/Y/Z Offset
Sets the X, Y and Z components of end.
Practical setup
A reliable workflow
- 1
Create particles and give them motion toward the collision area.
- 2
Add pBounce and choose an appropriate Region.
- 3
Place the region where particles actually intersect it.
- 4
Set Elasticity and Roughness.
- 5
Add variance or spin for a less mechanical result.
- 6
Render through pRender.
Typical node chain
pEmitter→
pBounce→
pFriction→
pRender
Examples
Where this node fits in real work
Sparks on a floor
Falling particles hit a horizontal region and rebound.
pEmitterpDirectionalForcepBouncepRender
Particle sphere collision
Particles bounce from a spherical boundary.
pEmitterpBouncepTurbulencepRender
Troubleshooting
Common mistakes
Placing the collision region away from the particle path.
Using perfect elasticity and zero roughness so every bounce looks identical.
Expecting realistic rigid-body physics from a stylized particle collision node.
Production notes
Practical tips
Visualize and position the region before fine-tuning bounce values.
Use some roughness and variance for organic effects.
Combine friction after bounce when particles should lose energy over time.
Related nodes