Crash when exporting 16-bit single channel textures from UE4 to Omniverse

Omniverse Connectors Unreal Engine
1

Method:

Create a greyscale 16-bit image in photoshop (pure white 1024x1024 will reproduce the error)
Save as .png
Import into UE4, leave compression as ‘default’
Right click ‘export to Omniverse’

Expected behavior:

Texture is exported to Nucleus

Actual behavior:

Unreal will hard crash with the following error (array size will change depending on the texture):

Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h] [Line: 703] Array index out of bounds: 2097152 from an array of size 2097152

Environment:
Unreal 4.27.2
Latest connector at time of posting

Are there any workarounds known for this?

2

Thanks for reporting this Alex, we’re going to look into it. We are tracking this internally with issue OM-54391.

I’d like to be sure that you were running 4.27 version 105.1.276, please confirm.

3

Yes -
4.27
105.1.276

4

Hi Alex,
I can’t repro your issue with the greyscale 16-bit image. So could you please send me your crashed UE asset? Maybe there’s something else caused the crash.

5

Hello - apologies for the long delay in replying.

The error really is any 16-bit grey scale image - I’ve uploaded one to google drive here:

I suspect this has more to do with the graphics driver - the machine(s) which demonstrate this issue are VMs with Windows Server build 1809 (17763.2928), and hence also (according to our datacenter managers) limited to a particular GPU driver.

We’re running 50% of a A40 per machine, and GPU driver 512.78. Omniverse ‘create’ complains about this, but appears to run just fine.

Is this a possible cause?

6

I just took a quick exporting with your png and it’s fine for me. I’ll let our QA also have the test.
BTW, the png is 16bit, but it’s not 16bit grey png.