For those who don’t know the tool: Paradigm is a GPU liquid solver that runs inside Houdini, alongside Axiom, using node based workflows for VFX liquid setups.

What 1.0 actually changes

Paradigm 1.0 targets GPU accelerated liquid simulation in Houdini, and the developer describes it as a “hybrid that can be called a FLIP solver while borrowing ideas from SPH”, whatever that means. It is supposed to be faster and more accessible than Houdini native liquid tools.

Version 1.0 ships as a sequence of point releases that stack up into something production artists can actually evaluate. The current notes focus on simulation stability, faster solvers, better sourcing, more outputs, and a Tank workflow aimed at open water setups. If you live in Houdini, this is the kind of list that determines whether you can keep a shot moving or spend the week explaining why it will be ready next week.

Sourcing gets less crunchy

The 1.0.153 to 1.0.175 updates bring a major round of sourcing work. Particle emission from source shapes improves, with spacing and layout described as more random and even, and with less repetition. A separate Particle Source node arrives to control emtoion timings in a way described as similar to source shapes.

Read more: Theory Accelerated shifts Paradigm 1.0 for Houdini

Sourcing can now push more than just positions. The solver can output particle attributes like color, temperature, viscosity, and rest as optional outputs, and it also adds age and life attributes plus lifespan controls to remove particles that age past their life value. It can also output churn, described as the magnitude of the curl of the velocity field, as an optional field.

The system also supports defining extra arbitrary particle attributes by defining them in the output tab of the solver node. Source VDBs can affect particle attributes, for example by sourcing a temperature volume source to make particles hotter. Temperature and color attributes can diffuse and dissipate. A relax force is described as now working properly and as fully deterministic. All of that translates into a much clearer story for lookdev and downstream controls. You get more handles, more outputs, and fewer excuses to bake everything into a single sim and pray.

The performance pass: SDF, advection, sorting

The 1.0.176 to 1.0.219 updates lean hard into speed and numerical behavior. A much faster SDF creation algorithm lands, plus changes to advection that make it faster by considering the SDF collision value when stepping forward. Adhesion becomes more accurate by using the collision SDF gradient for directions.

Particle handling also gets a leaf-based sorting method described as greatly improving the performance of grid sampling. The solver can better predict future resource needs when reinitialising, called Acceleration in the Advanced to Solver tab. There are also new filters for the output surface SDF, specifically erode and dilate filters, plus additional filtering options for the output surface SDF as a concept in the earlier 1.0.153 to 1.0.175 set. The end result is still an SDF output, not a finished mesh.

If you want a mesh, you still need to convert the surface SDF to a mesh using the VDB Convert node in Houdini. That’s cool for shot work, because it keeps the meshing and any post-smoothing in familiar Houdini territory, with all the usual caveats about voxel size, narrow features, and meshing time. You know the drill.

PCG everywhere: viscosity and pressure style steps

Viscosity gets a major upgrade in 1.0.176 to 1.0.219. It is described as much faster, with a new PCG-based solver. On the control side, multiple control ramps arrive for viscosity and gravity, and gravity and drag can be driven with control ramps in the earlier update set. Viscosity can be driven with a viscosity or temperature particle attribute, and there is collision conductivity for temperature diffusion plus the ability to source collision temperature for melting or freezing effects when particles touch a collider when using viscosity.

In practical terms, these controls push Paradigm closer to how artists like to art-direct liquids. You can tie behaviour to attributes, and you can do it without building a separate rig of custom forces for every shot. Also, a speed limit force bug gets fixed, where values could clamp incorrectly and produce a lower speed limit than expected. That is not glamorous.

Tank workflows and open water domains

Paradigm 1.0 adds a Paradigm Tank node for creating open water. These domains can be animated to have a moving container. Later updates describe the tank node as more stable and efficient at different scales.

For artists, that sounds like fewer edge cases and less time spent re-scaling a scene just to make the container behave. It also points to a workflow that is intentionally separate from classic boxed FLIP tanks, which feel like they belong to a different decade of fluid tools. And yes, I am thinking in decades; I am old.

Outputs, fields, and other useful knobs

The 1.0 notes mention more efficient sinks. Output field precision issues that could cause garbled outputs get fixed. Source shape noise can optionally cull source particles instead of just source values. Some blend modes get fixes when sourcing with source shapes.

None of this removes the need for real pipeline testing. New tools and innovations should always be tested before use in production, especially when the toolset is still evolving across frequent builds and wet behind the ears. (Obvious joke. Watersim. Wet. I need more coffee.)

What it does and does not include

Paradigm does not include narrow-band support yet. It does not currently have reseeding, though it is something likely to be added. A white water solver is in development, and the suggested current approach is to use Paradigm with Houdini’s white water solver.

Ocean spectrum workflows are described as not officially supported. The FAQ describes a possible approach using custom sources if the spectrum is converted to velocity fields and mask, with a desire to add full support for ocean spectrum in the future. That future support is not confirmed.

Compatibility and system requirements

Production builds of Houdini 20.0 and higher are supported. Daily builds are not supported. Windows, Linux, and macOS are supported. Nvidia and Apple GPUs are recommended, and any device that supports OpenCL 3.0 should work. Due to issues with drivers, some GPU may not be supported.

Pricing, licensing, and the parts people actually ask about

Paradigm Indie is $99 as a node locked license and can only be used with Houdini Indie. Paradigm Commercial is $199 as a node locked license and can be used with Houdini Core and FX.

Each node locked license includes one year of maintenance that renews annually, plus a perpetual license for all builds released during the maintenance period. A node locked license can be used on two devices at a time, with a maximum of two licenses per studio. Floating licenses exist for Paradigm Commercial via contacting sales.

The FAQ also states that Paradigm is free to use with Houdini Educational and Apprentice licenses, matching the vendor’s approach for Axiom. During the open beta for version 1.1, it is also free to use with no license or login required, with builds lasting 30 days from the date of publishing. The 1.1 open beta is scheduled to start in early May 2026. There is no release date, and the estimate given is 2 to 3 months, described as just an estimate.

If you are planning to integrate this fluid into a pipeline, test the licensing workflow, expiry behaviour, and Houdini version constraints in your actual studio environment. Then test again on the machine nobody loves, because that is the one that will end up simming the hero splash.

Where this sits in a broader Houdini sim stack

Liquid Thinking: Paradigm Brings GPU Speed to Houdini

Paradigm is a separate solver from Axiom, and the FAQ states there is no two-way coupling between the two. That does not stop you from using them in the same Houdini project, but it does mean you should not expect an automatic handshake between liquid motion and volumetric effects. You can still do the usual tricks using exported fields and caches, but the coupling is a pipeline job, not a one-click feature.

Axiom 4 for Houdini: Faster GPU Pyro With Better Collisions

This is also where expectations need to stay grounded. Paradigm outputs a surface SDF with filtering options, and Houdini converts that to a mesh. White water comes from Houdini’s own white water solver for now. Narrow band and re-seeding are not there yet. If your shots require those features, treat 1.0 as a serious tool that still leaves some work for you.

If you adopt it, run a focused test pass: emission behaviour, collisions with temperature effects, viscosity art direction, SDF meshing quality, and driver stability under OpenCL.

https://www.theoryaccelerated.com/paradigm

https://theoryaccelerated.notion.site/paradigm-1-0-whats-new

https://theoryaccelerated.notion.site/paradigm-1-faq

https://www.theoryaccelerated.com/axiom

The post Theory Accelerated shifts Paradigm 1.0 for Houdini first appeared on DIGITAL PRODUCTION and was written by Bela Beier.

Theory Accelerated is the independent R&D studio of former ILM and Naughty Dog technical director Matt Puchala. Known for Axiom, a GPU-based volumetric solver for Houdini, the studio builds specialised simulation tools aimed at faster, artist-friendly workflows for VFX and cinematics. Paradigm extends this approach from smoke and fire into liquid dynamics.

Theory Accelerated has released Paradigm, a new GPU-accelerated sparse liquid solver for Houdini. The software, currently in open beta, aims to provide a faster alternative to Houdini’s native CPU-bound FLIP solver. According to Theory Accelerated, Paradigm can simulate millions of particles “in a fraction of the time a CPU would take”.

Like its sibling tool Axiom, Paradigm is designed to handle simulations across scales—from small splash tanks to large-scale water scenes. The solver runs entirely on the GPU through OpenCL, making it hardware-agnostic and compatible with GPUs from AMD, Intel, and NVIDIA, as well as Apple Silicon.

Built on the same tech as Axiom

Paradigm shares its underlying sparse-simulation architecture with Axiom, Theory Accelerated’s established GPU-based volumetric solver. Development of the two products is intertwined; improvements made during Paradigm’s creation reportedly led to better collision detection in Axiom 4.0. Despite the shared lineage, Paradigm and Axiom are separate tools, and there is currently no two-way coupling between liquid and volume simulations.

Simple setup, Houdini-native workflow

Paradigm integrates directly into Houdini and is structured around a compact node set—just four nodes are required to set up a basic splash tank. Its interface closely resembles Axiom’s, offering familiar workflows for existing users. Artists can use source shapes as emitters, colliders, or custom forces.

According to the developer, the goal is to make iteration as fast as possible. Paradigm’s GPU core enables quick previewing of surface tension, viscositiy, and adhesion effects, helping artists evaluate sims without long cache times.

Still missing whitewater, but it’s coming

As of the current beta, Paradigm supports small- and medium-scale liquid simulations but lacks several production-level features. Whitewater simulation and full support for Houdini’s ocean spectra are not yet implemented. Upcoming updates are expected to add colour sourcing, temperature-driven behaviour, viscosity attributes, and support for narrow-band simulation. Matt Puchala describes the current build as “highly unoptimised”, but plans to bring Paradigm to “the same level of polish that Axiom has”.

Free to test until February 2026

The open beta is free to download for all users until the end of February 2026c (See the FAQ for details). After that, Paradigm will move to a commercial model “similar to Axiom”, offering both perpetual node-locked and floating licences. The software runs on Houdini 20.0+ across Windows, Linux, and macOS, and requires an OpenCL 3.0-compatible GPU. The documentation includes setup examples and sample projects. Installation requires creating a free Theory Accelerated account.

Early verdict: promising, but still maturing

While Paradigm’s GPU acceleration promises a major speed boost for Houdini-based liquid simulations, it is still in beta. Key production features, such as whitewater and advanced ocean interaction, are not yet ready, and the solver is described as unoptimised. For now, Paradigm is best used for testing and experimentation rather than critical production work. As always, new solvers should be tested on controlled scenes before deplorment in a production. And we’ll check out the next builds to keep you in the loop when it is worth your precious GPU-cycles!

The post Liquid Thinking: Paradigm Brings GPU Speed to Houdini first appeared on DIGITAL PRODUCTION and was written by Manuel Kotulla.

If you’ve ever watched your pyro sim clip through a collider and thought, “Physics has left the chat,” this update is for you.

Headline Features

The big one is collisions: animated colliders and narrow geometry now hold up better, with smoke and fire retaining density and velocity instead of evaporating into numerical limbo. On top of that, the sourcing workflow has been redesigned, so setting up emitters feels less like solving a puzzle box and more like… well, just setting up emitters. The interface has also gone through a detox. Parameters are now sorted into sensible tabs, with advanced options politely tucked away, which means less scrolling and more simming. Performance has had a small but noticeable bump too, with simulations running between 5 and 15 percent faster depending on scene complexity. On the CPU side, fallback multithreading now relies on Intel TBB, giving more stability when GPU memory runs dry. And yes, it’s time to check your Houdini version: Axiom 4 supports Houdini 20.0, 20.5, and 21.0, with 19.x officially stamped “legacy,” which is dev-speak for “upgrade already.”

What It Means for Artists

The gist is simple: smoke looks better when it interacts with geometry, simulations tick along faster, and you’ll spend less time digging for hidden parameters. For artists cranking out pyro in production, Axiom 4 is less about flashy new features and more about shaving off headaches per day.

Pricing

Nothing has changed here. The commercial license stays at $199, the indie license at $99, and if you’re running Houdini Apprentice you can keep setting digital buildings on fire for free.

Outlook

Axiom 4 isn’t about reinventing the solver wheel but about refinement. With sturdier collisions, smoother sourcing, and faster turnaround, this release makes it easier to trust that your smoke won’t ghost through a wall. For production artists, that’s often the only feature that really matters.

Release Notes

The post Axiom 4 for Houdini: Faster GPU Pyro With Better Collisions first appeared on DIGITAL PRODUCTION and was written by Bela Beier.