Instanced Stereo broken in 5.6?

Development Platform & Builds XR Development
1

We’re running into some strange issues after updating to 5.6 and after a few days of troubleshooting we’ve narrowed it down to instanced stereo.

To reproduce:

  1. Create a blank project from the launcher version of 5.6
  2. Keep all the default settings, including the deferred renderer
  3. Change instanced stereo to true
  4. Create an empty niagara system and open it in the niagara editor
  5. UE immediately crashes:
    Fatal error: [File:D:\build++UE5\Sync\Engine\Source\Runtime\RHI\Private\PipelineStateCache.cpp] [Line: 533]
    Shader compilation failures are Fatal.

UnrealEditor_RHI
UnrealEditor_RHI
UnrealEditor_RHI
UnrealEditor_RHI
UnrealEditor_RHI
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
kernel32
ntdll

We’ve also seen similar issues with scene capture components, but the niagara editor is the fastest way to reproduce the problem.

Is anyone else seeing this? Seems like a pretty significant issue. Our application is a hybrid desktop and VR, so instanced stereo is critical for us.

2 Likes
2

Thanks Ken we’re looking into it

1 Like
3

Thanks Victor! Fingers crossed it turns out to be something hotfix-able.

4

As an update, we were hoping that perhaps this was an editor-only issue. We did a packaged build and it still crashes with the same error.

5

I tested with forward rendering and it works fine. Probably just deferred issue only.

6

Hi Victor, have you guys been able to reproduce this internally and, if so, is it in the issue tracker yet? I’d love to follow it as it’s a critical issue for us.

Thanks!

7

This may or may not be the same issues as this:

Instanced Stereo + Virtual Textures

8

Hey Victor, has there been any progress on this? I can’t enable Instanced Stereo at all in 5.6, it crashes during project load. It throws the same error:

Fatal error: [File:D:\build++UE5\Sync\Engine\Source\Runtime\RHI\Private\PipelineStateCache.cpp] [Line: 533]
Shader compilation failures are Fatal.

I’ve tried turning off Virtual Textures and Ray Tracing, but that doesn’t help. I’m also using Deferred Rendering because my project is both VR and First Person.

9

I have this exact sazme problem. I was hoping it was going to be fixed in 5.6.

Whenever I use Niagra or my puddling FX in VR I cannot open my map.
Im badly in need of the extra fps too.

Its getting pretty bad waiting for this for a fix. Ive even thought about creating entire datalayer sets to switch instance stereo off when im in hallways etc but this would probably take me 4 months or so of 10 hour days to get it to where I need it to be, just for those extra 20 fps.

10

This was fixed on Main, but didn’t make it into 5.6.1: https://github.com/EpicGames/UnrealEngine/commit/f7e0f419bd5ecb8252bfc67eeda6577d78ab595c

3 Likes
11

Also running into the same issue with RVT and Instanced Stereo in 5.6.1

Does this mean it won’t be fixed until 5.7?

12

I’m still having a similiar issue (same crash when using InstancedStereo) using the 5.7 branch and a custom 5.6.1 with the fixes in the commit you pointed out:

Reproducible in a new project:

  • Turn on InstancedStereo → restart
  • Enable PCG framework and PCG Biome Core and PCG Biome Sample and open the BiomeSampleLevel in the PCG Biome Sample plugin content folder → Crash

it only crashes when InstancedStereo is enabled.

Edit: It seems to be related to the RVT (Runtime Virtual Texture) as mentioned above.

Thanks!