Fluid Simulation
The Fluid Displacement mode runs a GPU-accelerated Navier-Stokes fluid solver (Stable Fluids algorithm) on Metal compute kernels. Force generators inject velocity into a 3D volume; that velocity field is then applied to point cloud particle positions each frame.
← Point Cloud Displacement overview
Enabling
Section titled “Enabling”- Add a 3D track with a Point Cloud object
- Open the Point Cloud Displacement card in the inspector
- Click the FLUID DISPLACEMENT toggle to enable it
The solver starts immediately with no forces — particles remain still until you add at least one force generator.
Simulation parameters
Section titled “Simulation parameters”| Parameter | Description |
|---|---|
| Resolution | Simulation grid size: 128 / 256 / 512 / 1024 |
| Depth | Z-axis grid layers: 4 / 8 / 16 / 32 / 64 / 128 / 256 |
| Strength | How strongly the fluid velocity displaces particle positions |
| Fade | How quickly fluid velocity dissipates each frame — lower = instant fade, higher = long-lived trails |
| Curl | Adds rotational turbulence to the velocity field |
| Speed | Maximum velocity cap — higher = more chaotic self-interaction |
| Viscosity | Resistance to velocity diffusion — higher = smoother, larger-scale motion |
| Bounce | How much velocity reflects off the volume boundary — 0 = absorbed, 1 = elastic |
| Contain | When on, fluid reflects at the volume edges; when off, it wraps |
Strength and Decay appear below the simulation card and scale the final displacement applied to particles. Decay controls how quickly particle positions return toward rest when velocity is low.
Reset Fluid snaps the entire velocity volume back to zero instantly.
Force generators
Section titled “Force generators”Click Add Force to inject velocity into the fluid volume. Each force has a Strength, Pos X/Y/Z, and Radius (the Gaussian splat size of the injection).
| Force type | What it does | Extra parameters |
|---|---|---|
| Directional | Pushes fluid in a fixed direction | Dir X, Dir Y, Dir Z |
| Radial Out | Pushes fluid outward from the emitter position | — |
| Radial In | Pulls fluid inward toward the emitter position | — |
| Pulse | A single radial burst triggered by a mappable trigger | Trigger, Decay |
| Rotation | Spins fluid around an axis | Spin X, Spin Y, Spin Z |
| Vortex Sink | Swirling inward drain | Spin X/Y/Z (axis), Pull, Lift |
| Texture Force | Uses a track texture to drive velocity | Source track, Mode (RGB→XY / Luminance→Radial) |
| Noise | Turbulent per-particle force field | Scale, Speed |
| Drag | Slows fluid proportional to local velocity | — |
Up to 8 force generators can run simultaneously.
Symmetry mirrors all forces across an axis at once — useful for symmetric motion without adding duplicate generators. Options: None, Mirror X, Mirror Y, Mirror XY.
All force parameters (position, strength, radius, direction) are full modulation targets — right-click any slider to map it to an LFO, sequencer, audio range, MIDI, or OSC.
Performance
Section titled “Performance”Resolution is the main performance lever. Start at 128 or 256 and increase only if you need finer-grained flow detail. 1024 is very GPU-intensive — use it for final output or on high-end hardware.
Depth controls Z-axis resolution. Higher depth gives true 3D volume but multiplies GPU memory usage. Keep it at 4 or 8 unless you need distinct front-to-back flow layers.