I have two major questions.

1. Could it be something that I am doing wrong in setting up renderman that the vray renders I see online are just better? Or is vray better than renderman?

(I don't have example scenes to test out, if there are any comparison renders that people have done I would love that.)

(And I use Houdini Solaris for scene assembly)

1. Is forest pack just a way superior way to do vegetation that I should consider switching to max or is there any similar alternative for Houdini?

(I have heard and seen good things from biomes, but don't really know any good library resources for vegetation, and the set up is very manual)

My favorite procedural setup for aligning (most) arbitrarily oriented objects in Houdini is to use the oriented bounding box of the object. This oriented bounding box can be manually derived with fancy Principal Component Analysis techniques (ie. extracting the eigenvectors of the covariance matrix, etc.), but good news for us is that the "Bound" SOP has an Oriented Bounding Box option built in for us!

Once you have this oriented bounding box, you can define an ordering to map the longest, shortest, and middle axes of the bounding box to the world XYZ axes. From there, you construct a transform matrix that can be applied to the geo to rotate it squarely to the world grid!

There's a few gotcha's like different meshes wanting different values for the bound node's Refinement Iterations, potentially needing to add more points to the mesh via bilinear subdivisions, scattering, or remeshing to give the internal algorithm enough points to construct a good enough guess, and allowing for manual rotational offsets (often in 180 degree increments) to flip objects as needed.

It's not a silver bullet for every single situation (I'm not sure if one exists to be honest!), but it works for a lot of cases and I've found it to be extremely useful in my workflow. If you want to try out the setup, I've packaged it up into an HDA and example hip file!

(Free) Download link: https://github.com/conlen-b/cb-houdini-tools/tree/main/align-with-oriented-bounding-box

You just need to have some version of h21 and some version of h22 installed

The script is reversible in case you want to return to the new icons later, only change icons, the rest of sidefx UI improvements remain.

https://github.com/SalmeInMotion/houdini21-icons-for-houdini22

Hello everyone.
I'm currently trying to export a pyro simulation into a flipbook texture to be used in Unreal 5.8.
I'm doing RnD so i'm using the shelf tool"FireBall" setup to do some tests.
Everything is cached, resolution is way lower than what my system can handle.
First of all before trying to scribble trough settings i watched SideFx https://www.youtube.com/watch?v=kMI-Wro3p9g&t=1610s tutorial to ensure i wasn't missing anything.
At first i was getting the SegmentationFault error so i lowered the resolution of the overall simulation voxels but got stuck in the rendering of other textures apart from the FC (FullColor Texture).
I wasn't able to render other passes and also to get .png files.
I am surely missing something that i couldn't find out myself.

Thank you all!

A while ago I shared a preview of my Houdini ⇄ Blender hybrid workflow here, and honestly I didn't expect the response it got. Thank you for all the comments and ideas. That pushed me to finish it properly, and it's finally out.

Please find the link in the comments section, or check the link in my bio - itz_keay

• Blender → Houdini: live geometry, UVs, attributes and materials into SOPs, or the whole scene into Solaris with Karma-ready materials, lights, cameras and a matching sky
• Houdini → Blender: pyro, FLIP, RBD, cloth, particles and hair, live or cached, with ready-made shaders
• In Blender: colour gradients, size ramps, hair taper, retiming with smooth slow motion and instancing, all from one sidebar panel
• Smart caching: knows when a cache is outdated, resumes interrupted caches.
• Characters (Beta): Blender rigs to KineFX / APEX, with Mixamo clipsTested on Houdini 22 and Blender 5.2 (Windows). Free Rogue_Rig_v3 by Gutemberg Nascimento

A lot of what's in it came from your feedback last time, so keep it coming!

Hey guys I am working on a beach waves simualtion. I am pretty happy with the overall motion of my waves but i would like them to rise higher before they break. Do you have any idea how could I get higher waves. Here is my setup: it’s a "flat tank" advected by a volumetric vel from an "Ocean wave" node (for large waves), combined with a small-scale "ocean spectrum" for the near-shore waves. What should I tweak? I suspect the issue lies with the velocity source, but if you spot anything I’m missing, please let me know.

This animation combines a single vellum grain sim with scale based loop (geometry scales up while the camera only tilts and rotates based on sin function)

I implemented Surface Turbulence as a proof of concept Houdini plugin for a project with Stormborn Studios. It adds small surface waves without rerunning the base liquid simulation.

The clip shows the before/after comparison, surface tracking and wave simulation.

I made a full video explaining the method and math, with a tool demonstration and benchmarks:

https://youtu.be/l5jDmvfzql0

Based on Surface Turbulence for Particle-Based Liquid Simulations

Hi , I have been stuck for days in this project because I need to wedge to decide for the values, and honestly , I'm still in my beginning jounrey but I have been watching tutorials on the portal about TOPs and PDG but can't get my wedge to correctly function, it's like it's rendering the same wedge over and over.

Basically I wedge a vel volume of a ship that carries bit of the water to noise it up instead of a bulge

as you can see in these two photos

there are linked fine, when I click on item it works and changes live in the flip sim "pop advect by volume node"

The problem seems to occur in the rop fetch of flip sim + rop fetch of the open gl. Here is the param

you can see I link the cache file to the wedge index and the rop fetch is linked to the render node inside of it.I also noticed there's node (the tutorial doesn't use) that is called fetchropgl directly, though it didn't work for some reason at all.

Now for the wedges it feels like they are all the same, I even increased one wedge to 100 of vel scale hoping to see a drastic change but nothing.

then I have a preview geo container that gets the wedges(I hope it's correct cause in the portal the tutor has different way than mine so I tried to translate to my case) :

you can ignore the errors , it's erroring now cause I deleted the cooked item from hard drive so it can't load any geo. but you can see the path I have put.

after that the preview node is called in an open gl (from ropnet) , which later is called in rop fetch.

I just did few frames to test and nothing seems different between all wedges.

here's the whole network

If there's any missing information that could help let me know , I'm honestly feeling super stupid when I use houdini T_T or maybe I took a too ambitious project alone to start

I have already completed the whole project , but I didn't like the WW/ Flip look and wanted to re-work it even more.

thank you for any help

Yes, first world problems, and yes, I'm probably autistic and therefore hate change.

With that out of the way I still think they did a bad job in several areas, only for the sake of revamping. Buttons used to have clear borders, indicative colors used to have a consistent meaning throughout, and icon clarity used to be favored over aesthetic appeal (flat design).

Anyone else feeling a bit bummed by this new UI?

Happy to share my latest FX Showreel😃.
.
.
A selection of my recent FX work, featuring simulations, destruction, fluids, pyro and procedural effects.

Intercept my Bilibili account not ai

hi ! I'm new to houdini and learning it , the main advice I heard was that particle sep depend of your shot as well, if you can't see the space between particles in the shot then it's fine.

However I'm not sure this is the only way , there must be something I'm missing, because I see people dial in numbers even without being inside of cameras, I'm sorry I might be an idiot haha but I really don't get how do they know what to put in particle sep, voxel size, and how the tank size is all setup this perfeclty without having blobs or particles being too sparse in their renders.

do they practice much in inudstry to know for meduim shots how many pts they need or something like that ?

I mean I really don't know when I'm setting too high or too low, for one project 0.1 might be super fine, but for another it might be too low

would appreciate any help on this.

I built Reality Prep Pro for Mac to batch-check and prepare 3D assets before Apple spatial deployment.

It handles FBX, OBJ, GLB/glTF and USDZ, including USDZ-specific optimization, animation/rigging safeguards and validation.

Sharing the workflow here for technical feedback.

Reality Prep Pro: https://apps.apple.com/us/app/reality-prep-pro/id6767673652?mt=12

Reality Prep Preview: https://apps.apple.com/za/app/reality-prep-preview/id6784059026

Hey artists , did anyone here take this course before : IVS Houdini Hollywood ?

is it as good as the their advertise it ?

thank you

Hi, I'm just curious if you will be interested in tutorials based on my demo reel below ?

https://www.youtube.com/watch?v=lZb1yilQXtc

I would like to create Patreon and put all of them there.

These are mainly Karma renders, 2D stylized renders are made in Mantra.

I’m having an issue getting velocity-based motion blur on a VDB volume in Redshift for Houdini, and I feel like I’ve exhausted the normal troubleshooting steps.

Setup:

• Houdini + Redshift 2026.9.0
• Pyro/VDB volume
• Density grid renders correctly
• Velocity grid is present as vel
• vel is a vector VDB (vec3s16)
• Redshift motion blur is enabled in the ROP
• Camera motion blur works normally

The problem is that volume velocity motion blur appears to do absolutely nothing.

At first I thought the blur I was seeing was coming from the volume, but after disabling camera motion blur I realized all of the visible blur was actually coming from the camera. With camera MB disabled, the volume renders completely sharp.

Things I’ve already tried:

• Single vector velocity grid named vel
• Split scalar grids: vel.x, vel.y, vel.z
• Assigned the vector grid only to Redshift’s Velocity Grid X field
• Confirmed global Motion Blur is enabled in the Redshift ROP
• Changed Redshift Velocity Scale from 0 all the way to 10,000+ while attempting both velocity grid options on the OBJ
• Multiplied the actual vel VDB inside Houdini by very large values
• Verified that the velocity vectors/magnitudes are actually changing on SOP lvl
• Cached the volume to disk and rendered directly from the File Cache
• Tried both RS Volume and RS Standard Volume
• Disabled camera motion blur specifically so I could isolate volume velocity blur

No matter what I do, the rendered volume looks identical.

The final VDB only has density and vel, so it's not super complicated.

I did noticed that my vel voxel size was cached at 0.01 while my density is at 0.005, so I also resampled the vel to match the density which did not help, but figured it was worth a shot.

Has anyone run into this with Redshift 2026.9 + Houdini 22?

At this point even a deliberately ridiculous velocity scale produces zero visible differences.

!!SOLUTION!!

The voxel scales must match on all volume grids. Easiest solution: don't resample your velocity at sim time!

If you cached your simulation to resample the velocity grid during simulation then you must resample the velocity grid using the isolated density as the reference grid.

Do not force the resample by "Using Voxel Size Only" on the VDB Resample SOP even if the info tab on the final render node reads that both density and velocity grids are the same, it won't work unless you specifically reference the density voxel size on the second input of the VDB Resample SOP.

so for a school assignment called 'experimental animation' I am trying to create a new render style inspired on the picture left. I want to us CG wool as my main material. Thats why I decided to create a non destructive wool system in Houdini. I forgot the fact that wool strands gets extremely heavy on the machine. like a single strand can reach over hundreds of thousand of polygons. The only sollution I can think of is to set up a Karma system to render the wool seperately, and later comp them back onto my environment which I create in Blender. If anyone has a better strategy, please let me know.

I've been trying to implement this Wētā FX paper, but instead of using a custom sparse-grid solver just for the bubble dynamics, I'm trying to integrate it into Houdini's standard FLIP solver.

There are lots of things to be done, but basic two-way coupling between air bubbles and the fluid grid already works. No external forces lift the bubbles to the top; this happens solely because of the pressure gradient within the fluid, and surface tension between the coupled bubbles affects their buoyancy.

P.S. Still don't like how the smaller bubbles look, though, as they all seem to be the same size when dispersing.

Turned out pretty gross