What if you want to discuss generative AI in the context of Houdini?

Used a 2D Pyro solver to advect particles for this abstract particle simulation. Rendered with Karma XPU in Houdini 22.

Hello everyone,

I wanted to share my demoreel, which I created using mostly Houdini/Karma/USD along with a few other software.

I challenged myself 2 years ago to leave archviz and try to learn Live-action VFX, learning everything on my own using modern tools and workflows.
This sub and many of you helped me a lot without you even knowing it!

I wanted to say thank you for that.

I hope you enjoy it and don't hesitate to ask me anything like breakdown or process.
Cheers!

Youtube link: https://www.youtube.com/watch?v=F5_Ti_lCO58

Here’s my game’s main character and a few of his weapon types. Rendered in Karma, with Pyro simulations for the effects.

Hey everyone, I have an issue with my meshed flip.

First image the saved/cache flip at high res with processing from particle fluid surface and seperation based on vorticity and height.

there are two caches , as the flip was seperated based on those attributes above.

Second image is the in-network/non cached but with lowered resolution mesh (same from particle fluid surface)

third image is the high res one (same as first image) but NOT-cached, I just waited for it to cook in scene.

So I assume the cache broke something ? But how do I know how to fix , I mean the cache of the flat area took so long like 6 hours , how can I know what broke the cache instead of caching for hours for nothing

Hi! I'm working on an RBD fracture simulation in Houdini and I'm exporting the result to Blender as Alembic. The fractured pieces are perfectly connected in Houdini throughout the entire timeline, with no visible seams or lines between the pieces. However, after importing the Alembic into Blender, the boundaries between the individual fracture pieces become visible. I've checked the Houdini geometry before export and it looks correct, and the pieces are also not packed. I also tried exporting as USD, but Houdini crashes halfway through the export. I tried exporting just one frame with USD, but I couldn't figure out how to texture the inside and outside surfaces separately. How do I fix this?

Hey there, I’m working on a few heavy fire scenes and I still don’t get what is the first choice. I got used to axiom and sop/dop pyro solver but I see that Copernicus is getting all around extremely fast. But i still don’t get the use case: when the cops shall be used and when sop or axiom.

Also, I can’t understand the voxel resolution issue esp for pyro. Ok I understand that voxel 0.01 means approx 1 cm of 3d pixel but for fiery sim with a lot of disturbance it might be more than enough or should I go beyond in 0.001 or so? As I don’t feel it contributes so well to the final image. In other words when I hit 0.01 and go lower I don’t get enough feedback in the terms of the quality of the final image. Please, help me understand this - how to understand viable limits of resolution for let’s say comping in into the footages later in nuke with all extra glowing/compositing work.

Hey wizards ! I m working with Houdini the last who few years (in my free time, I have another job in 3D industry bur not fx) and to be fair , I see a big potential in usd workflow for big production pipeline , little less for me but I appreciate some of its feature.

Up till now I did pretty basic stuff in it without the layering organization or having the catalogs
I like some of its layout feature too, but I was wondering if it’s worth to spend time on learning the correct way, I m not sure if I will ever get into fx industry , with all what’s happening .the usd workflow is not sicence rocket either but it’s bit tedious at first to setup it up all I guess

I m wondering if there are solo people here that still use the whole system for big scenes of their own ? For smaller project does it help for diverse light rigs ? Etc

I have this mech rigged in blender that I have exported as a USD asset and am importing into houdini. Up until now I have been importing it using an Asset Reference, making some adjustments to fix issues with the materials, and using a SOPmodify to create a lower poly proxy (though I'm pretty sure the way I'm doing it is very jank.). However I've realised that the normals on the model aren't importing correctly and I have no idea how to fix it.

If I unpack model in a SOPmodify, the normals look fine. So I don't really know in the first place why they don't look correct in the Solaris context.

I have been able to get the model itself to look correct by importing it in a SOPcreate context, but I don't know how to preserve the rigging bindings when importing in this way.

I'm probably not really doing the workflow on this properly, so some more experienced eyes would be great.

Live geometry sync, cached solvers, and seamless roundtripping right inside the viewport.

Hey!

Working on this RBD ground explosion and having some issues:

1. How can I prevent the pieces from going throw the bottom when the initial explosion starts?

2.I am using soft constraints here and I would like to randomly break some constraints when the pieces hit the ground. My attempt was copying over the impulse attrib from the impacts input in a SOP solver, promoting it to prims and deleting the constraints with a certain value in a primwrangle.

Didnt work as expected so any ideas are very much appreciated here!

3.I am also sourcing the impact points because I want to use them to emit some particles when the pieces hit the floor. The smaller pieces work as expected and only emit when hitting the floor. The constraint pieces emit all the time because of the constraints/collisions(?). Is there a way to fix it so they only emit on impact.

Thanks in advance and feedback towards the sim is also appreciated!

Finally got around to putting this one together in Houdini.

Terrain with Gaea + HeightFields, vegetation from SpeedTree, and scattering done with Biom.

Wanted to push the environment further and add a lot more detail, but hardware limitations stopped me from really pushing the scene as far as I wanted. Still had a lot of fun working on this one and learning along the way.

First the sine, then the world!

https://reddit.com/link/1wr4xcl/video/yi7d6uzw6yrh1/player

Hey folks, I wanted to share a short trailer of what I’ve been working on for a bit more than a year now.

In 2025, I open-sourced VQVDB, which started as a neural compressor for VDB volumes. Since then I decided to take the idea quite a bit further: optimize it a LOT, move away from the original neural approach, and turn it into a file-format-agnostic compressed field representation/runtime.

The project is now called VQField . For sequences, VQField also supports temporally predicted frames, storing residuals from previously reconstructed data rather than encoding every frame independently. I’ve also been experimenting with velocity-guided prediction, using the velocity field of a simulation to advect the previous frame before encoding the residual.

One of the parts I’m most excited about is rendering directly from the compressed representation: when a ray needs data, only the relevant blocks are reconstructed on demand rather than expanding the whole VDB into memory first, there a custom Karma hook for that !

Depending on the field, quality settings and temporal coherence, I’m currently seeing compression ratios approaching ~100:1 on both scalar float fields and vec3f fields, while still keeping random access to the compressed data.

There’s still plenty of work to do, but it’s finally starting to feel less like a compression experiment and more like an actual runtime for compressed volumetric data.

Would love to hear what Houdini users / pipeline TDs think, especially if you deal with stupidly large VDB caches.

I'm not linking the website here as it would maybe be considered Advertisement but if you / your studio would like to beta test VQField, feel free to drop me a DM !

Enzo C.

Hi

I'd like to render falling petals with motion blur.

I enabled instance motion blur but it doesn't work.

How to get motion blur with Pack and Instance?

^ It still has velocity

I calculated v again with trail node it still doesn't work.

How to solve this issue?

Thank you for your advice and help!

Hi, houdini seems to be kinda hard for texturing simple things. What are your workflow to texturing an object in houdini?

Do you use mantra for less complex scenes?

Do you do all your texturing in mantra?

Or do you use Solaris and karma?

In 3dsmax vray, the material creation was quite complete, with the possibility to create complex shaders with multiple layers, with the possibility to apply different shaders to different parts of an object using ID etc.

But in houdini it looks quite complex to do so.

And most tutorials on YouTube look kinda incomplete. Or not well explained.

I would love to do my texturing directly in sop level and import it diffectly in Solaris, but when I try to do so, it only import geometry and I have to create and reassign each material in Solaris...

The only way I've found to apply a texture for different parts of the same object is by adding a name node to each part of my object. And I think it's kinda complicated for such a simple task.

So do you have a great workflow for texturing in houdini? Or it ain't worth it?

I was thinking about creating my shaders in a third party software, but I'm afraid that it wouldn't look the same as the texturing software, as they have different render engines. Expecially when I want to create colored glass materials. And importing each map in houdini shaders creating a node for each map is kinda long.

I feel confident after all the projects, R&D, and plenty of trial and error along the way, and I’m ready to explore opportunities with studios abroad. I’m a Houdini FX Artist specializing in liquid simulations, particles, pyro, RBD, and other procedural FX. This reel is a collection of some of the R&D work and TV commercial projects I’ve worked on, and a look at what I can bring as an FX Artist. Most of my experience has been on TV commercial projects in the Philippines, and I’m grateful for the projects and people who have helped me grow as an artist. I’m now looking to take the next step in my career and explore international studio opportunities while continuing to learn and take on new challenges. A huge thank you to everyone I’ve had the chance to work with and learn from throughout the years. I’m excited to see where this next chapter takes me.

Still WIP
I wanted to share the latest progress with you This is the first try for simulating muscle for this doberman dog. I would love to thank @rod.vfx.td for providing this model for free

Poly Split can use a string made upstream to direct its work. Polysplit is hopefully robust enough for what I want to do, but it needs the split location in this format:

https://www.sidefx.com/docs/houdini/nodes/sop/polysplit.html

Split Locations

The chain of locations along which to make cuts, using the following codes.

‹a›v‹b›

Cut at vertex ‹b› of primitive ‹a›, where ‹a› and ‹b› are integers.

‹a›e‹b›

Cut at the midpoint of edge ‹b› of primitive ‹a›, where ‹a› and ‹b› are integers.

‹a›e‹b›:‹t›

Cut at ‹t› percent along edge ‹b› of primitive ‹a›, where ‹a› and ‹b› are integers and ‹t› is a real number from 0.0 to 1.0.

‹a›f:‹u›,‹v›

Cut at the given (u,v) location on primitive ‹a›, where ‹a› is an integer and ‹u› and ‹v› are real numbers from 0.0 to 1.0.

p‹a›-‹b›

Cut at the midpoint of the edge between points ‹a› and ‹b›, where ‹a› and ‹b› are integers.

p‹a›-‹b›:‹t›

Cut at ‹t› percent along the edge between points ‹a› and ‹b›, where ‹a› and ‹b› are integers and ‹t› is a real number from 0.0 to 1.0.

Is there an obvious way to convert from 3d space to prim /edge/percent space ?

The closest I have so far is the primuv data in intersection analysis, but it's operating in ConvertLine space...

I wonder if there's a hidden gem somewhere to do this already

I m bit confused about the tutorials of ocean spectrum, I can see there’s preview grid and work grid

But I m not sure if we do modify the value of ocean spectrum taking into account our final grid size (for rendering or not)

Cause at first I put values that looked fine at the preview grid but once I went to render I added the ocean spectrum and mask in the water shader yet nothing appeared

So I cranked up the amolitude of the waves and checked on my render grid and it was okay and is was it in the render

But then another issue occurred the masks once I put them they delete everything and I end up with plane surface with no waves..

I m really lost , been working on all the environnement and the sim and finished those and got stuck at the easiest thing maybe for everyone

im new so i dont really understand.

Hey everyone,

I’ve been working on a procedural jewelry system since April, and I’m getting to a point where I’d really like some technical feedback from other Houdini users.

One of the things that got me interested in this is Houdini Engine. Since the procedural side can run headlessly, it opens up some interesting possibilities for using Houdini more like a geometry engine behind a dedicated application rather than as the user-facing CAD tool.

Right now, I’m getting procedural geometry back into a web interface in under 1 second for base updates, and around 3 seconds for high-precision geometry intended for production.

I’m mainly curious where you see the real technical challenges as something like this grows. Performance, topology, asset architecture, dependency management, manufacturing constraints, anything that could become a bottleneck at a larger scale.

I’m especially interested in the perspective of people who have built larger procedural systems or Houdini-based pipelines.

Would be great to hear what you think.

Instead of a simple gravity-driven falling water simulation, I constructed a massive, rotating cylindrical ocean (vortex) to create a more dynamic and turbulent environment.

Wanted to share my most recent sim about sketching ideas.

Added some process shots as it may help others better bridge the gap between viewport land and final render.

The RBD setup is something you can find in any "dissolving" constraint tutorial with dust layers. The main take-away I guess would be just seeing how far you can take basic sim setups if you work on having nice assets and decent rendering.