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.

The release of INSYDIUM Fused 2025.4 introduces a rebuilt NeXus core that accelerates GPU simulation performance while reducing VRAM usage. The system handles particle and fluid data more responsively, and the update brings expanded mapping controls such as looping data channels and layered GPU falloffs that increase procedural flexibility. The changes shift NeXus closer to a general purpose GPU simulation framework inside the host DCC.

INSYDIUM develops simulation and animation technology that integrates directly into Cinema 4D. The company’s toolset is distributed as the Fused bundle, which contains NeXus for GPU accelerated simulation, X Particles for particle based workflows, Taiao for procedural vegetation, Cycles 4D for rendering and a series of utility modules for meshing, shading and scene structuring. The suite provides an internal alternative to standalone solvers by keeping particle effects, smoke, fire, fluids, meshes and procedural animation inside the Cinema 4D environment without external roundtrips.

What Is New In Fused 2025.4

Fused 2025.4 introduces a rebuilt NeXus core that increases GPU simulation speed and reduces VRAM usage. The update improves responsiveness during heavy particle or fluid work and adds expanded mapping controls such as looping channels and layered GPU falloffs. These changes make the system more suitable for complex effects work where simulation data needs to be adjusted repeatedly without long rebuild times.

Expanded GPU Smoke, Fire And Liquid Simulation

Several new solvers extend NeXus into full smoke, fire and liquid simulation. nxExplosiaFX processes smoke and fire entirely on the GPU and can emit from meshes, splines, vertex maps, shaders or particles. The system supports layered emitters, collision objects and forces, while the viewport can display volumetric previews and diagnostic information that assists with look development.

nxFluids adds FLIP and APIC based liquid solvers that handle varying viscosity, thin liquid sheets and surface tension features with improved stability. These solvers respond well to high velocity motion and produce more predictable shapes in turbulent scenes. For converting simulations into renderable geometry, nxMesher produces mesh surfaces with reduced temporal flicker. It supports multiple mesh profiles, layered smoothing and the transfer of simulation attributes such as colour, velocity or emitter identifiers into the resulting geometry. Foam and spray handling moves to a new system under nxFoam, which provides more stable behaviour in fast moving flows. nxSplash introduces a procedural method for generating crown splash shapes for shots that need controlled impact elements.

Layer Based Modifier Workflow

NeXus modifiers now operate through a layer based workflow that consolidates several behaviours into single modifiers. Formerly separate nodes for turbulence, motion offsets, directional changes or scaling can now be stacked inside a unified container. The workflow reduces the complexity of particle setups and improves clarity in scenes that rely on multiple behavioural adjustments. Several modifiers receive technical refinements. nxDirection gains more precise control for stream shaping and vortex behaviour. nxFollowGeo adds multi spline support and new guide and force modes that improve geometry following in both smooth and turbulent contexts.

Jidou Brings Procedural Animation

Fused 2025.4 introduces Jidou, a procedural animation toolkit designed for clones, hierarchies and technical setups. jdAniMate manages start and end PSR states with detailed timing adjustments. jdDriver links arbitrary parameters to create dependency based rigs. jdFlowCam generates structured camera paths with holds and timed motions. jdGeoFlow creates procedural curves that can drive object deformation or placement. jdGeoRoll simulates rolling behaviour with gravity and collision handling for mechanical or motion graphic tasks. Jidou serves as a parallel system to simulation work, covering the areas where predictable procedural motion is required.

Production Considerations

NeXus simulations continue to run on a single GPU. Distributed or team rendering cannot offload simulation data because the processing remains tied to the local GPU. Systems running Windows may require TDR timeout adjustments during long simulation sessions to prevent GPU resets. NeXus requires a GPU with Vulkan support and a minimum of 4 GB VRAM. Performance scales with newer GPU architectures and should be evaluated in context of scene complexity.

P.S. On their site, you’ll find the 4K Wallpapers gallery – https://insydium.ltd/community/4k-wallpapers/ , and I’ve been using the “Flip Particles” for a while on my PC. Worth a look!

The post INSYDIUM Fused 2025.4: Faster NeXus, New GPU Sims, And a Procedural Animation Toolkit first appeared on DIGITAL PRODUCTION and was written by Bela Beier.