pTurbulence

pTurbulence accepts an existing particle stream and makes motion less uniform by imposing procedural frequency-based chaos. It does not emit particles or draw pixels; a minimal diagnostic graph is pEmitter → pTurbulence → pRender.

Blackmagic's Fusion Tool Reference describes pTurbulence as imposing frequency-based chaos on the position of each particle so motion becomes unpredictable and uneven. Judge that behavior during playback rather than from one still frame.

X Strength, Y Strength and Z Strength set the amount of chaotic motion on each axis independently. During diagnosis, leave only one axis non-zero so its contribution remains readable before mixing all three directions.

The captured Resolve Inspector shows a baseline of 0.1 for X/Y/Z Strength. That is a useful conservative starting point, not a universal look; perceived motion also depends on emitter velocity, lifespan, frame rate, particle-scene scale and neighboring forces.

Strength Over Life is a LUT/curve that multiplies turbulence according to normalized particle age. Particles can be calm at birth, become more turbulent mid-life and settle again near death without another force node.

Density controls the spatial frequency of the turbulence field. Higher values produce finer variations while lower values create broader structures. It is therefore different from Strength: Density changes the character of the field rather than simply its amplitude.

A Blackmagic Visual Effects Guide exercise uses Density 75 as an example of steadier, less coarsely chaotic particle motion while retaining turbulence. This is a useful reminder that Density should not be read as a simple 'more chaos' control.

Random Seed and Reseed change the reproducible variation of the procedural field. Keep the seed fixed when comparing Strength, Density or Strength Over Life, otherwise a different pattern can be mistaken for a parameter effect.

Time Lock belongs to common random/time behavior in particle tools. It is not a simulation freeze and does not replace pRender Restart, Pre-Roll, Pre-Generate or Sub-Frame Calculation Accuracy.

Conditions > Probability is evaluated for each eligible particle on each frame. A value of 0.5 does not select one permanent half of the particles for their whole lifespan; eligibility is probabilistic over time.

Age Start/End is a normalized 0–1 lifespan range rather than timeline frame numbers. This makes it possible to delay turbulence until, for example, the last 60 percent of each particle's life.

Set Mode and Set 1–32 filter Sets that were assigned upstream. pTurbulence does not create Set membership; assign it earlier with pEmitter, pImageEmitter, pChangeStyle, pSpawn or another compatible particle tool.

Region is a separate spatial gate. It decides where pTurbulence may act without changing the meaning of X/Y/Z Strength, Strength Over Life or Density.

Region Mode supports ignore, intersecting, inside, not intersecting, not inside, entering and leaving conditions. Keep Region ignored for the first baseline so spatial gating does not hide the turbulence behavior itself.

All, Bezier, Cube, Line, Rectangle and Sphere are built-in Regions and require no external cable. Bitmap and Mesh are the exceptions: selecting them creates a dynamic Region input.

Bitmap Region accepts a 2D image/channel as a spatial gate. It is not an Effect Mask for a rendered RGBA image and it is not the primary particle input; verify the channel or alpha used by the gate separately.

Mesh Region accepts 3D mesh geometry and may use surface/volume interpretation, winding controls and ObjectID filtering. It limits where turbulence is applied but does not turn pTurbulence into a 3D renderer.

pTurbulence works well after pDirectionalForce or pTangentForce once the broad motion is already understood. Prove direction or curvature first, then add turbulence as a separate layer of irregularity.

A downstream pFriction is useful when turbulence and other forces accumulate too much velocity. Tune generation of motion first and damping second instead of forcing one Strength control to solve both jobs.

The output remains Particles. pRender later converts the stream into a visible 2D image or 3D particle output, so ordinary image operations such as Glow, Blur or ColorCorrector belong after the pRender boundary.