Significant Changes Coming To VR Resolution Settings in 4.19

[Ivey]

@muchcharles

WMR and Oculus Rift via Steam VR were both broken in 4.18, but they are fixed in master with this change. Here’s a couple threads on the issue:

https://answers.unrealengine.com/que…n-instead.html
https://forums.unrealengine.com/deve…ession-in-4-18

I’ve tracked it down to the aspect of the native screen res on the HMD differing from the aspect of the ideal rendertarget (GetRecommendedRenderTargetSize).

Rift just legitimately gives a different aspect ratio, which should be handled (and is in master and 4.17).

WindowsMR doesn’t try to give a different aspect ratio, but the way UE4 is querying native screen res (VRExtDisplay->GetWindowBounds) breaks and returns the screen res of the Rift and Vive (2160x1200) even on Windows MR, which differs from the actual aspect of most Windows MR devices (1440x1440 or 1440x1600) and their recommended render targets.

4.17 didn’t care if the aspect ratios were different, but 4.18 does. 4.18 seems to have inadvertantly done this while adding adaptive pixel density, but adaptive pixel density doesn’t actually work for me on Vive in 4.18 and the interface changes in 4.19. I think 4.18 should just be reverted to the 4.17 behavior in a hot fix.

Edit: Added a pull request here that hopefully should fix things: https://github.com/EpicGames/UnrealEngine/pull/4354

Thanks for the feedback on the current implementation and the suggestions on what we could change to fix!