Memory is not freed when switching scenes

To reproduce:

  • open Attic sample
  • switch renderers a few times (should use ~8 GB or so of VRAM)
  • open EuclidVR stage – note memory is not freed despite the scene being relatively small.

Quit CREATE, reopen, open only the EuclidVR stage – note ~2.4 GB of VRAM used

Actually 2.4GB of VRAM at the start of the program even with an empty scene is about right. The program itself takes some memory just to load up.

To clarify, maybe that was confusing:

  • Opening Attic and THEN Euclid (so, Attic is not open anymore): uses 8 GB of VRAM
  • Close Omniverse, open only Euclid: uses 2.4 GB of VRAM

So I think there may be an issue when opening multiple scenes that the memory for previous scenes is not cleared properly.

The way the development has explained this in the past, is that Create will use and hold on to VRAM during the whole session. It will allocate the VRAM for a heavy scene, and once allocated, it will store it for re-use in other scenes later. So the reporting of VRAM looks like you are still using 8GB, but in fact the new smaller scene is 2.4GB inside the allocated VRAM buffer. ‘Some’ memory will be returned when reseting to new scene or a smaller scene, but not all. It is dymamic.

The reporting tool, therefore can be a little misleading and we are looking at ways to make it less so.

The important thing is that Create runs smooth all the time. If this is the case, you are within your VRAM. If you notice the program’s UI and general responsiveness slow way down, you should close and reopen the software to flush the VRAM.

Hm, this isn’t great for a tool that is just one part in a wider ecosystem (e.g. DCCs, other engines, …). If every app would be doing this people could only ever use one software at a time. I strongly recommend the devs look at this with less of a “our software is the only one that ever runs on a user’s machine” look…

We are currently developing a new memory manager to address the issues of memory allocation more efficiently. Once I find out when this might be made available to the next public release, I will let you know.

1 Like