Geometry & 3D node
3D Paths
Every particle leaves a PATH — a persistent line of where it has been, drawn in the 3D Scene with the scene's lights and shadows. Cable the Particle System's Particles output in (the same cable 3D Particles takes). Points are laid down by distance, not by frame — Min Spacing is the pen's step — and Path Length is how much history each line keeps: a full line crawls forward like a snake. When a particle dies its path does not vanish; over Retract Time the tail runs forward along the very curve the particle drew while the head coasts on by Head Drift, and the line leaves the world the way it entered. Fade tapers the width toward the tail. Flow made visible — murmurations become calligraphy.
Inputs
| Port | Type | Default |
|---|---|---|
| Enable | bool | true |
| ParticlesThe Particle System's Particles output — the same cable 3D Particles takes. Both children can share it: the flock and its calligraphy. | structure | — |
| Max PathsHow many lines can exist at once. A particle without a free slot simply waits; a slot frees when its line finishes retracting. | int | 512 |
| Path LengthHow many points of history each line keeps. A full line crawls forward like a snake — the tail follows the head. | int | 128 |
| Min SpacingThe pen's step: a point is laid every this much TRAVEL, not every frame — slow drifters and fast darts both draw clean, even lines. | float | 0.02 |
| WidthThe ribbon's width in Grafit units, stamped into each point as it is laid — animate it and the thickness paints along the line. | float | 0.015 |
| FadeTapers the width toward the tail — 0 is a constant band, 1 a comet that thins to nothing. | float | 0.7 |
| Record DelaySeconds of life before the pen touches down — the birth flight from the emitter draws nothing, only what comes after. | float | 0 |
| Stuck OnlyThe pen writes ONLY while the particle rides a surface (Particles Along Geometry). The flight to the mesh draws nothing; the calligraphy stays on the skin. | bool | false |
| Retract TimeHow long a dead particle's line takes to leave: the tail runs forward along the very curve the particle drew until nothing remains. | float | 1.5 |
| Head DriftHow far the head coasts on past the death point, easing to a stop — the line finishes its gesture instead of freezing mid-stroke. | float | 0.3 |
| LitThe scene's lights tint the ribbons, dust-mote style. (Tube mode is always lit — full PBR.) | bool | true |
| ShadowedThe scene's shadow maps fall on the ribbons — a line through a light shaft goes dark where the shaft is blocked. | bool | true |
| ModeRibbon: a translucent eye-facing band, cheap and airy. Tube: REAL geometry swept along the curve — full PBR surface, per-pixel shadows, and it can cast its own. | int | 0 |
| SidesThe tube's cross-section: 3 is a triangular strand, 6 round enough for most lines, 8 the smoothest — and the vertex bill scales with it. | int | 6 |
| MaterialA Material node's surface — cable one in and it overrides Color, Roughness, Metallic and Emission below. One Material can feed Meshes, mesh particles and these tubes alike: one surface, edited in one place. | structure | — |
| ColorThe tube's surface — one material for all paths, lit like any mesh. Ribbons keep each particle's own colour instead. | color | (1, 1, 1, 1) |
| RoughnessThe tube surface's finish — low is lacquered wire, high is matte cord. | float | 0.45 |
| MetallicMetal tubes reflect their colour like wire; dielectric ones read as painted. | float | 0 |
| EmissionSelf-glow — the tubes become neon, and Bloom downstream picks them up. | float | 0 |
| Cast ShadowsThe tubes throw REAL shadows — the calligraphy lands on the floor. Costs a shadow-map redraw every frame, same as casting particles. | bool | false |
| Path IndexWhich active path the Path output hands out (0-based, clamped). Cable that output into a Sweep or Curve Deform and the flock's trace becomes real geometry. | int | 0 |
Outputs
| Port | Type |
|---|---|
| Points | structure |
| Path | structure |
| Path Count | int |
How It Works
3D Paths makes every particle leave a persistent trajectory, drawn in the 3D Scene with the scene's lights and shadows. Cable the Particle System's Particles output in — the same cable 3D Particles takes.
Points are laid down by distance travelled, not by frame (Min Spacing is the pen's step), so slow drifters and fast darts both draw clean lines. Path Length is how much history each line keeps: a full line crawls forward like a snake.
The detail that makes it work: when a particle dies its line does not pop. Over Retract Time the tail runs forward along the very curve the particle drew while the head coasts on by Head Drift — the line leaves the world the way it entered it. Fade tapers the width toward the tail.
Ribbon mode is an eye-facing band; Tube mode is real generated geometry with a Material, full PBR and shadows it can cast. The pen knows when not to write (Record Delay, Stuck Only).
The recorded lines also come back out as data: Points (every path as a cloud), Path (one line, ordered) and Path Count — so the flock's trace can feed a Plexus, or be swept into a mesh of its own.
Use Cases
- Calligraphy from a flock — Murmurations become drawn lines.
- Flow made visible — A vector field's shape shown by the routes particles take through it.
- Light trails — Emissive tubes with shadows in a dark scene.
- Trace to geometry — The Path output into Sweep makes a permanent mesh of a motion.
- Plexus on trails — The Points output as a cloud that connects to itself.
Tips
- Min Spacing is the pen step in world units — too small and the line is heavy, too large and curves become polygons.
- Max Paths × Path Length is the memory budget; both cost.
- Tube mode is real geometry and can cast shadows; Ribbon is much cheaper and eye-facing.
- Retract Time is what makes deaths look intentional. Zero is available, but the lines will pop.
- Stuck Only is for surface-riding particles: record the line only once they have landed.
- The same recorder is available as a particle Type: Ribbon (Path) for patches that never touch a 3D Scene.
Open 3D Paths in the interactive catalog →
3D Paths is one of 381 nodes in Grafit Pro.
Free download. Every feature for 7 days, no card. Then €99.99 once — or keep playing your projects as a Player.