Rigging & animation · Advanced

Fluid simulation

Making liquids, smoke and fire move realistically in 3D

What is fluid simulation?

Fluid simulation is a physics simulation that makes liquids, smoke and fire move realistically. The software splits a space into tiny cells or particles and calculates how the fluid flows, splashes and swirls through them, frame by frame. It is one of the heaviest effects in 3D.

Think of it like this

Like tracking every marble in a tank full of them, every moment: more marbles give a more lifelike flow, and far more work.

Where it fits in a 3D project

  1. Create
  2. Surface
  3. Rig
  4. Animate
  5. Render
  6. Export

Animate: Making things move over time.

How fluid simulation works

  1. 01Set a domain, a box the fluid can never leave.
  2. 02Add a source, such as a tap pouring liquid or a fire giving off smoke.
  3. 03Mark obstacles the fluid should flow around.
  4. 04Choose a resolution, simulate, then bake to disk before rendering.

Where fluid simulation is used

  • Pouring drinks, splashes and product shots
  • Ocean waves, rivers and rain
  • Smoke, steam, fire and explosions

Beginner tip

Test at low resolution until the motion looks right, then raise it for the final bake. Detail grows in three directions at once, so a final run can take hours.

Terms related to fluid simulation

Fluid simulation FAQ

Liquid vs smoke simulation: what is the difference?
A liquid simulation tracks a surface, the water’s skin, which becomes a mesh for rendering. A smoke or fire simulation tracks density and heat through a volume, which renders as soft, see-through haze instead of a hard surface.
Why is fluid simulation so slow?
Every cell or particle in the domain is calculated at every step, and detail grows in all three directions at once. A small rise in resolution means far more cells, more memory and much longer bakes.
What is domain resolution?
How many cells the simulation box is divided into, usually counted along its longest side. Higher resolution gives finer splashes and wisps, at the cost of time and memory.

Updated October 29, 2026 · Browse all 3D terms