Low memory availability

I have 2X RTX 4090 24GB and after few minutes when I turn on/off objects using buttons and rendering, whole memory is used. After that when I want to ON some object, they wont load. Now I get message in console “2023-03-10 09:42:27 [Warning] [omni.hydra] Processing of geometry is paused due to low memory availability. 657 objects are left in the queue.”

What should I do? Is possible to somehow release memory when I am in “play mode”? Or my only chance is to optimizing my scene? What is worst: too many objects, too many poly or too many materials? Thanks

I’m getting the very exact same issue! Just followed your post to see if any working fix arises.

To help you out, I’ve had that many assets and even more in my scenes, and would work fine with low frame rate obviously, but still works (using RTX 3060 Ti). Recently, I’ve been getting the same issue you’re getting. Did you change the maximum texture streaming settings by any chance? or used the Paint tool to paint multiple assets in scene?

Before using these, everything worked fine but I don’t think the issue is coming from there. Try a new scene with less assets, and check that you’re using USDs with lesser materials used in scene. Try to re-use materials when you can. See if you’re getting the same console message regarding objects in queue!

Hope my message stems into a fix mate!

Hi Ryan. Well my scene has approx 650 objects, maybe 50-100 different materials and this state is after cleaning. I dont get it why, but I dont use paint tool or changing texture streaming. I do that after this issues.

Same here mate, was working fine but all of a sudden I’ve been getting high memory usage from my GPU. So even with a new project without any assets in scene, you’re still getting high memory usage?

No…I am ok with small scenes…I think its like low memory release after using iray renderer. After turn on iray, memory will be filled, but after turn off iray there is not enough mem release. IDK why. I thought that the renderer solves this themselves.

Ok I see, and does it happen when switching to Path tracing rather than Iray renderer? Try reloading the scene and switch to Path tracing instead of Iray. It was working likes you’re saying before last week, in my case. Then all of a sudden I was getting high memory even after switching to real time rendering and in a fresh new empty scene!

Well I am fine with path tracing. But maybe just because I have 2x 4090…mmm maybe there is some bug after last updates.

Could be mate… If I find a fix, I’ll let you know, Cheers!

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Can you send me your scene so I can take a look ? Also any video capture of the memory being used would be helpful.

Realtime and Interactive use the same vram memory pool on the GPU. However, IRAY, uses its own memory pool, and it will require a rebuild of materials and geometry, thus consuming more vram.

She issue here.

I looked at Twin Motion then bought a compatible PC and adopted Omniverse last spring/summer. We developed several projects on the NVIDIA platform then stepped away to focus on other project types.

I recently downloaded a fresh version of Create (2022.3.3). Seems that was a huge mistake.

All but the smallest and simplest of projects are DOA due to the same memory issue. Right now, I cannot get more than bright red geometry for most projects as they stall/pause without a means to restart loading. I suspect it’s a conflict in latest version.

No time to bug test and we need to make reliable progress as the project clock is ticking. Dang… Sad to say, this pushes me back toward Twin Motion.

Glad to hear of a fix to – at least – recover past projects and hopefully continue forward again with Omniverse.

Update: The last version I used was still locally accessible and I was able to open the files in OV 2022.2.2 Beta. Any further info is appreciated as we’re otherwise hoping for a fix in future versions.

Hi Thom
I would offer the same as I did to the other users on this thread. Can you send me your scene, collected and zipped together so I can take a look ? We have a variety of hardware we test on. I can test it on my 24GB 3090 and see what is happening. I have never really experienced this. I can load very large and complex scenes and they run smoothly.

Are you specifically having trouble with IRAY (Accurate) ? Let me take a look at your scene and see what is happening.

was a solution found? I have 4090. After a few minutes of playing, assigning some materials, the mem pool was 0.

I have the same issue. I have a 4090, and after a couple of still renders at 5K, Composer becomes unstable.
We’re building a USD pipeline and Omniverse is for us the way to go.
But this VRAM issue (which we don’t have with other tools like Houdini, Blender, Unreal) is a problem.
For now, we’ll keep using Omniverse and Nucleus as the core of our USD pipeline in the making, but we’re looking into other renderers. Especially since we need to render prodcuts that have advanced transparent materials with IOR on transparent background, with a shadow+reflection catcher plane. Only iRay behaves properly with the shadow catcher and these advanced alpha situations, but iRay doesn’t support light linking. We can find ways around the light linking limitations, but, using iRay, we need to restart OV afer 2 or 3 renders at a resolution of 5000x5000. That’s not scalable / production ready enough at the moment.

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Yes we are aware of the shadow matte problem in RT and PT. You should not be running out of memory though. Very strange. Are you able to send us one of your scene files for testing ?

I agree that the memory management still needs a lot of improvements. VRAM fills up much then in offline rendering engines I use. For example one of the V-Ray scenes takes up to 16GB of memory for 4K render while very similar scene but made inside USD Composer takes all 24GB of VRAM and becomes very unstable while rendering.

Thanks Richard.
I will setup a scene that reproduces the case in iRAy (can’t share the scene in question, as it’s under NDAs etc.). I’ll ping that over as soon as I can.

@_stef And just curious but why are you using Iray Accurate instead of Realtime or Pathtracing ? Iray is good, buts its legacy and our older renderer. Much slower than the other two.

@Richard3D We would love to be able to use PT. Realtime won’t have the level of fidelity for refraction, dispersion, caustics, etc.
A part of our pipeline involves product rendering on transparent BG.
Some of these products have transparent materials.
We can’t find a way to get a trasparent material to render on a transparent background “correctly”. There are a few catches: the pixels of the transparent materials are often contaminated by the environment dome light, and or (dependending on the cam angle) the shadow catcher plane. Then, it is also hard to get a clean reflection catcher too.
I’m now trying to find a way (even if we have to render several pass separately without a premultiplied alpha) to get good results for post compositing.
I’m trying without luck to output a clean alpha channel for the transparent/translucent materials.
And I’ve not yet tried to render several transparent objects together with PT ( i.e. a transparent liquid inside a transparent container).
I’m trying to get the right AOVs or LPEs for rendering these alpha, shadow, and indirect reflection passes separatly.

For info, UEs deffered and PT renderers have the same issue, I’ve talked to Epic devs at the Epic Fest 23, and it seems to be a tough-nut-case to crack. :)

Attached are preview renders that are slow but close to what we want, using iRay. Which is not ideal, as we’re wasting a lot of cool tech like light linking and more.

The forum’s uploader API converts PNGs to JPG on white, so I’ve uploaded screen grabs with a checker BG. (I know, transparency is expensive AND tricky ;-) )

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