pFollow

pFollow is a Fusion particle modifier for spring-like following toward a point. It does not create particles and it does not render RGBA; it receives an existing particle stream, changes particle motion and passes the stream to pRender or another particle node.

The core concept is a separate follow object whose location is defined by Position X/Y/Z. Particles do not teleport to that point: they begin springing toward it, can overshoot it, return, and oscillate around the new motion path.

Position X, Y and Z define the follow object in 3D space. Animating those coordinates creates the new path that influences particles. This is the primary way to turn pFollow from a static attraction into controlled motion through the frame and depth.

Spring controls the elasticity of the spring motion. Higher values strengthen the tendency to catch the follow object and make back-and-forth motion more pronounced; excessive Spring with insufficient Dampen creates visible overshoot and oscillation.

In the current Resolve 21 reference the second main control is named Dampen. It attenuates the spring action: lower values leave more free oscillation, while higher values add resistance and settle motion around the follow object more quickly.

Spring and Dampen should be tuned as a pair. Spring is not merely attraction speed; it shapes the elastic response, while Dampen removes energy from that response. The same Spring can look very different at different Dampen values.

Distance between a particle and the follow object influences the spring behavior, and the spread of spring motion develops over particle life. pFollow therefore needs playback-range evaluation rather than a single freeze-frame judgement.

The follow object and Region are separate concepts. Position X/Y/Z defines the point particles spring toward; the Region tab defines only a spatial condition that determines where pFollow is allowed to affect a particle.

Conditions > Probability defines the chance of applying the behavior to an eligible particle. As with the shared particle controls, Probability is calculated for each particle on every frame; 0.6 is not a fixed 60-percent subset for the entire lifespan.

Start/End Age limits pFollow to a normalized portion of particle lifespan rather than absolute frame numbers. For example, a Start value of 0.5 can leave early motion free and enable following only during the second half of life.

Conditions > Set Mode and Set 1–32 can target specific particle Sets or exclude them. Those Sets must be assigned upstream by nodes such as pEmitter, pImageEmitter, pChangeStyle or pSpawn.

The default topology contains only one orange Particles input. It accepts particle data from pEmitter, pImageEmitter, pMerge or another particle node. Ordinary MediaIn/RGBA imagery is not a valid particle-stream source.

The additional Region input does not exist permanently. It appears dynamically only when Region is set to Bitmap or Mesh. Bitmap accepts a 2D image/selectable channel; Mesh accepts 3D mesh data, and the connector color can depend on which option was selected first.

Built-in Regions—All, Bezier, Cube, Line, Rectangle and Sphere—are generated inside pFollow and require no external cable. A simple Particles → pFollow → pRender topology remains valid even when a built-in Sphere or Rectangle gates the effect.

Region Mode decides how the area gates pFollow: ignore region, intersecting, inside, not intersecting, not inside, entering or leaving. This is the condition for applying the behavior, not the geometry choice; geometry is selected separately by the Region menu.

A Line Region is defined by Start/End XYZ points that can be linked to Paths or Trackers. Rectangle remains a planar Region without Z depth, while Cube, Sphere and Mesh provide volumetric/spatial options.

Mesh Region uses the shared particle Region system: Region Type selects surface or volume, Winding Rule and Winding Ray Direction help determine inside/outside for complex or open geometry, and Limit By ObjectID/ObjectID can isolate one object in a mesh branch.

pFollow is commonly paired with pFlock, but their roles are different. pFollow supplies the moving target and spring tendency, while pFlock adds neighbor-aware spacing and flocking behavior between the particles themselves.

A restrained pTurbulence before or after pFollow can remove mechanical cleanliness, but it should be added only after Spring/Dampen already produce a predictable baseline. Otherwise it becomes hard to identify which node causes instability.

pFollow output remains particle data. A visible image appears only after pRender. If the topology is connected correctly but the Viewer appears empty, verify pRender and the emitter stream before trying to feed MediaIn directly into pFollow.