Try new Houdini GPU liquid solver Paradigm free in open beta
Theory Accelerated – aka former ILM and Naughty Dog TD Matt Puchala – has unveiled Paradigm, a promising new GPU-accelerated sparse liquid solver for Houdini.
Like Axiom, Theory Accelerated’s well-regarded volumetric solver, it is intended to provide a faster alternative to Houdini’s native simulation tools, but for liquids rather than smoke and fire.
The software, which is currently available free in open beta, is intended for sims of all sizes, and can “simulate million of particles in a fraction of the time a CPU would take”.
A faster alternative to Houdini’s Fluid FX tools for liquid simulation
Houdini already has a powerful set of tools for liquid simulation, but they’re primarily CPU-based: while the FLIP solver can use the GPU for specific tasks, for example, it’s CPU-bound.
Paradigm, which is fully GPU-based, is intended to provide a faster alternative to some of those tools, making it possible to iterate on effects much more quickly.
According to Theory Accelerated, “simulations that used to take hours can now be created in minutes”.
The software makes use of OpenCL for GPU acceleration, so it’s hardware-agnostic: it should be compatible with current GPUs from AMD, Intel and NVIDIA, and Apple Silicon processors.
Based on the underlying tech from the well-regarded Axiom solver
Paradigm is built on the same technology as Axiom, Theory Accelerated’s popular GPU-accelerated sparse volumetric solver, which is used in production for VFX and game cinematics.
Development of one tool feeds into the other: according to Puchala, early work on Paradigm led to the improvements in collision detection in Axiom 4.0.
However, they are completely separate products, and don’t integrate directly: according to the online FAQs, there is no two-way coupling between the two solvers.
Still in development, but you can test it free in open beta
Although Paradigm still isn’t feature-complete, you can now test it for free in open beta, while Theory Accelerated gathers user feedback.
For small-scale simulations, like liquid pours and splashes, the current beta build already supports surface tension, viscosity and adhesion.
However, while it will scale to large simulations, it still lacks features that would be important in production, like whitewater, and full support for Houdini’s ocean spectra.
Other features currently in development include color sourcing, the option to use point attributes like temperature or viscosity to drive simulations, and narrow band support.
Writing on LinkedIn, Matt Puchala said that the current build is still “highly unoptimized”, but that he now aims to take Paradigm to “the same level of polish that Axiom has”.
Price, system requirements and release date
Paradigm is currently free in open beta until the end of February 2026. You don’t need to be an Axiom user to download it.
After that, it will become a commercial product, with a pricing model “similar to Axiom”, which is available as perpetual licenses: node-locked for individual artists, and floating for studios.
The software is compatible with Houdini 20.0+ on Windows, Linux and macOS. It requires an OpenCL 3.0-compatible GPU.
Read more about Paradigm in the online documentation
Download the open beta of Paradigm
(Requires registering for a free account on the Theory Accelerated website)
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