Houdini 20.0 Pyro

Introduction to Pyro

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Pyro refers to Houdini’s volumetric fluid simulation package. The pyro solver is used for capturing the motion of fire, smoke, and explosions, but can also be used to simulate other fluid-like phenomena, such as mist or an avalanche.


In contrast to FLIP, pyro does not use particles to track the fluid. Since particles are very useful for resolving the surface, pyro is not well-suited for simulating liquids.

Getting started with pyro using shelf tools

The tools on the Simple FX shelf generate pyro simulation networks using the Pyro Solver SOP, which is a SOP level wrapper around the pyro dynamics building blocks. These tools provide a fast and friendly user experience, and avoids the need to build a dynamics network manually.

You can alternatively use the tools on the Pyro FX shelf to put down example DOP pyro setups. They create pyro networks that include sourcing on the at the geometry level, a DOP network for the simulation, and an output object to import results of the simulation back into a renderable object.


The tools on the Simple FX shelf are typically a better alternative as they are simpler to get started with, more user friendly, and don’t require a separate dynamics network.

All of these are extremely useful for creating instant simulations that can be further modified to integrate with your scene.


Sparse Pyro

Pyro instancing

Legacy Pyro