Particles node
Particles Along Geometry
Makes particles RIDE a mesh. Cable a Geometry in, and particles born within Tolerance of the surface stick to it and move ALONG it — every force still applies, but only its tangential part survives, so gravity streams them down the slopes into the hollows, negative gravity climbs the ridges, and fields herd them across the skin. Stick Mode widens capture from birth-only to any contact; Adhesion is the escape threshold (0 = unbreakable); Friction brakes the slide (1 = frozen in place); Hover floats them above the surface; Surface Flow adds a built-in curl current along the skin; Align To Surface turns cubes and mesh bodies to stand on it. Render the mesh with a 3D Mesh from the same cable — or don't, and the particles ARE the shape.
Inputs
| Port | Type | Default |
|---|---|---|
| EnableOff releases the particles from the surface; on again they snap back to it. | bool | true |
| ShowDraws the ridden mesh as a debug wireframe in its placement frame — the same lines the constraint kernel sees, so “why don’t they stick HERE” answers itself at a glance. | bool | false |
| GeometryThe mesh the particles ride. Any Geometry cable — a primitive, a Sweep, an L-System, a deforming shape. Show it with a 3D Mesh from the same cable, or hide it and let the particles BE the form. | structure | — |
| ToleranceThe capture distance: a particle closer to the surface than this sticks. It also floors the search cell, so very large values coarsen the grid. | float | 0.05 |
| Stick ModeBirth: only particles BORN within Tolerance ever stick — the rest fly free. Any Contact: whatever touches the surface later is captured too, so a falling cloud snows onto the shape. | int | 0 |
| AdhesionThe escape threshold. 0 is an unbreakable bond; above 0, a particle yanked away from the surface faster than this (units/sec along the normal) tears free — wind strips them off the form. | float | 0 |
| FrictionBrakes the slide along the surface. 0 is frictionless — gravity streams particles down every slope; 1 freezes them in place, a particle sculpture. | float | 0 |
| HoverFloats the riders this far above the skin — an aura, fur, a swarm holding formation just off the surface. | float | 0 |
| Surface FlowA built-in curl current that herds stuck particles ALONG the skin — no separate field node needed. Negative reverses the drift. | float | 0 |
| Flow ScaleThe current's spatial scale: small = broad slow rivers, large = fine turbulent eddies. | float | 1.5 |
| Flow SpeedHow fast the current's pattern itself drifts and churns over time. | float | 0.3 |
| Align To SurfaceTurns each particle so its up faces the surface normal — cubes and mesh bodies stand ON the form like scales. Overrides the emitter's own rotation. | bool | false |
| Pile UpPersonal space for the riders: stuck particles push apart to Pile Spacing, so a gravity-fed stream ACCUMULATES in the hollow like sand in a bowl instead of the whole flock collapsing into one lowest point. | bool | false |
| Pile SpacingThe rest distance between piled particles — the grain size of the heap. A particle’s own body size wins when it is larger. | float | 0.05 |
| Position XWhere the mesh stands in the particle system's space — match it to the 3D Mesh that renders the same cable. | float | 0 |
| Position YWhere the mesh stands in the particle system's space — match it to the 3D Mesh that renders the same cable. | float | 0 |
| Position ZWhere the mesh stands in the particle system's space — match it to the 3D Mesh that renders the same cable. | float | 0 |
| Rotation XThe mesh's turn, Euler degrees, Grafit clockwise — the same contract as the Geometry collider. | float | 0 |
| Rotation YThe mesh's turn, Euler degrees, Grafit clockwise — the same contract as the Geometry collider. | float | 0 |
| Rotation ZThe mesh's turn, Euler degrees, Grafit clockwise — the same contract as the Geometry collider. | float | 0 |
| QualityHow dense the riding mesh is, against the source: Full is exact contact; Half and Quarter ride a decimated proxy — the honest dial for heavy or animated geometry. | int | 0 |
How It Works
Particles Along Geometry is a surface constraint child of the Particle System. Cable any Geometry into it and particles born within Tolerance of that surface stick to it and move along it. Every force in the system still speaks — gravity, fields, turbulence, attractors — but only its tangential component survives, so gravity streams particles down the slopes and into the hollows, a negative gravity climbs the ridges, and a vector field herds them across the skin.
The mesh is indexed into a CSR grid on the GPU so the nearest-surface query stays cheap at a hundred thousand particles. Stick Mode widens capture from birth-only to any contact, so a falling cloud snows onto the shape. Adhesion is the escape threshold (0 = unbreakable); Friction brakes the slide, and at 1 the particles freeze into a sculpture on the form. Hover floats them a little above the skin, Surface Flow adds a built-in curl current along it, Align To Surface stands cubes and mesh bodies up on the form like scales, and Pile Up gives the riders personal space so a stream accumulates in a hollow like sand in a bowl.
Show draws the ridden mesh as a wireframe, which answers "why don't they stick here" without any guessing. Quality trades accuracy against speed by riding a decimated twin of the mesh.
Use Cases
- Particles as the shape — Don't render the mesh at all: the riders are the form, and the geometry is invisible scaffolding.
- Snow, sand and dust — Stick Mode: Any Contact plus gravity and Pile Up gives snow settling into the recesses of a model.
- Flow over a body — Surface Flow plus Align To Surface makes a current that reads the volume: hair, scales, fur, streaming light.
- A frozen sculpture — Friction 1 captures the cloud exactly where it landed, so an animated arrival becomes a still.
- Data on a surface — Feed the Particle System from a point cloud and let it settle onto a mesh: a map of readings wrapped around a form.
Tips
- Tolerance is a capture radius, not a snap distance. Too small and nothing sticks; too large and particles are yanked from far away.
- To render the mesh and the riders, cable the same Geometry into a 3D Scene's Mesh child — one source, two consumers.
- An animated mesh re-fits its acceleration structure; keep Quality at Half or Quarter while the mesh is moving and raise it for the still frames.
- Position and Rotation on this node place the ridden surface without touching the Geometry node, so one mesh can be ridden in two places.
- Pair with 3D Paths to draw the trails the riders leave on the surface.
Open Particles Along Geometry in the interactive catalog →
Particles Along Geometry 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.