Originally posted on 20 September 2021. Scroll down for news of the Axiom 2.2 update.

Former ILM FX TD Matt Puchala has released Axiom 2, a major new version of the popular GPU-accelerated sparse gaseous fluid solver for simulating effects like smoke and fire inside Houdini.

Version 2 of the solver adds new simulation source types and forces, support for colour dissipation and diffusion, a new Volume Visualize node, and a lot of workflow and performance improvements.

The release also makes the software, which was previously available free, a paid-for plugin, although it is still free for non-commercial use.

A faster alternative to Houdini’s spare Pyro solver for look development
First released in 2020, Axiom is a GPU-accelerated sparse gaseous fluid solver, intended as a faster alternative to Houdini’s Sparse Pyro solver for look dev work.

Like the native solver, Axiom is intended to provide near-real-time viewport feedback on complex fire and smoke simulations, speeding up look development.

However, unlike the CPU-only Sparse Pyro, Axiom is GPU-accelerated via OpenCL, falling back to the CPU if a simulation exceeds GPU memory: each GB of GPU memory is enough for around 8.5 million voxels.

A ground-up rewrite of the solver – and now a commercial tool
Axiom 2 is a ground-up rewrite of the solver – it isn’t backwards-compatible with previous releases – adding new features throughout the toolset.

Changes include a new Cone source shape for simulations, a new Spin force type for source shapes, support for color dissipation and diffusion, and a new Volume Visualize node.

Workflow improvements include control ramps for wind and cooling rate, axis-based control fields, and new Shelf tools and set-ups. According to Puchala, the solver is also now “5% more memory efficient”.

However, for many users, the biggest change will be that the software is now a commercial plugin, although you can still use it for free in trial mode, or in the non-commercial Houdini Apprentice.

 
Updated 10 January 2022: Matt Puchala has released Axiom 2.1

It’s a performance-focused update, improving overall performance by “10-25%” and introducing 64-bit memory allocation, raising the maximum size of a simulation to 2 billion voxels.

 
Updated 12 April 2022: Matt Puchala has released Axiom 2.2.

The update focuses on memory optimisation, making Axiom a further “5% more memory efficient”. In addition, native Metal support is now in public beta, which should improve performance on macOS.

Other changes include a new Python panel and profiling mode, to troubleshoot bottlenecks in simulations.

Pricing and system requirements
Axiom 2.2 is compatible with Houdini 18.0+ running on Windows, Linux or macOS. The software is hardware-agnostic: find a list of recommended AMD and Nvidia GPUs here.

Full node-locked licences now cost $399; floating licences cost $499.

The software can also be used free in trial mode or inside Houdini Apprentice; the Indie edition, which is compatible only with Houdini Indie, costs $99.

 
Read a full list of new features in Axiom 2 in the Vimeo description of the launch video

Read more about Axiom on Matt Puchala’s website

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