Screenspace reflection cutoff distance jarring in VR

[buckjohnston]

I am using deferred renderer and with that screen space reflections. What bugs me in VR is when you look down at a shiney floor you can clearly see the screen space reflections cutting off. The cutoff moves with your head. I checked the post processing volume and there is no setting to change the cutoff distance for screen space reflections. Does anyone know how to do this?

Edit: Also I am not interested in the forward renderer and planar reflections at this time.

[xN31]

SSR are not very suitable in VR because they can reflect only objects currently visible in the screen and this limitation is very noticeable in VR. I don't think there's a cutoff distance of any kind, the reflection fades when the objects that should be reflected are currently out of screen. The best approach is currently using reflection captures + planar reflections, but I understand these may not be a good fit for your project.

[buckjohnston]

Thanks for the info but they overall look really pretty good to me in VR. In general though yes that is the issue. The reflection are "out of the screen" and this screen size is being defined somewhere I just need to know where. This seems like it would be a very important variable to be able to adjust for VR because the SSR look fantastic in VR really.. it's only the cutoff distance or this screen size that is the problem.

In fact this cutoff is happening even in desktop mode when I check and look down at my feet, so it doesn't even seem VR specific. Images attached (of koola's lightroom for testing) you can see that as I move the mouse down the outside window stops reflecting and you can see the cutoff line. If it is necessary for me to render things that can't be seen on screen to fix this I'd be willing to do that if there is a setting somewhere. But I don't understand why it stops reflecting the top of the tree when it can clearly be seen. So I am not sure if UE4's ssr just needs further work done to it in general.

[wickerman123]

"Screen Space" is the key factor here. You're getting that cutoff line because the top of that window frame is no longer visible on the screen - therefore it can't be shown in the reflection.

The tree getting cut off is a separate issue. With screen space effects, there always seems to be less space allocated than the actual window - causing this sort of border, which could be contributing to this issue. I don't think it's something that can just be tweaked because the same drawback can be seen in many AAA games that make use of Screen Space reflections.

The only solution is Planar reflections but that has a high cost and isn't really suitable for VR.