We are about to develop a bigger UE5 project (whole city rebuild) and would love to be able to use nanite in VR in the foreseeable future. We need to plan out building 1500+ buildings. Can we relate on more geometry (Nanite) or should we build it with only Virtual Textures in mind and minimal geometry. Please give us some hints: will Nanite work in VR with 5.1 or 5.2???
From what Iāve researched nanite isnāt supported on VR platforms at all. If itās coming or not I donāt know. It would be an absolute game changer to the VR scene if it does.
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Hello, My current knowledge is that Nanite will support VR (no timeframe) and thatās itās just a matter of āplumbingā.
I was actually able to find the source of my info by searching the transcript for āplumbingā 
Cheers.
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This is awesome! Iām super excited for when it becomes available now that Iāve heard this. I was thought it was a technical limitation, but heās saying they just havenāt gotten to it yet lol. Thatās tremendous. Now hopefully it can work on dynamics meshes also and then weāll be in another world altogether (pun intended).
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Great news:
As can be seen in link, support will be added already in 5.1!
- Initial Stereo support for Nanite and Lumen, PC/Deferred Renderer only.
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You should also consider the performance of your application. When are you going to release it and what is the target market/hardware? For VR you want to hit 90fps. With Nanite you also will have to use Lumen for lighting. You also donāt want to use any upscaling (no TSR or DLSS) as that will introduce ghosting and that is something you donāt want to see in VR. It might take another generation or 2 of graphics cards before hardware is fast enough to get 90FPS with nanite for the resolutions required for VR.
if you google it youāll find a bunch of articles and demos even weeks ago demoing Lumen and Nanite in 5.1
Testing UE5's Nanite and Lumen in VR for example
or if you want to go to the source, thereās Alex Coulombe on Twitter:
https://twitter.com/iBrews
Why wouldnāt you use Nanite without Lumen for VR? You could just set up static lighting.
According to the documentation (Nanite Virtualized Geometry in Unreal Engine | Unreal Engine 5.0 Documentation) nanite uses a fallback mesh when using baked lightmaps.
From what I can see Iām getting fully detailed meshes regardless of swiching Lumen on/offā¦ I think maybe it uses the proxy in the lighting calculation (when calculating bounces etc.) but you still see the full mesh in normal rendering.
Ah ok, could also be that the documentation is outdated 
In 5.0 nanite is not supported in VR (doesnt support stereo). Meshes will use the Nanite fallback mesh that gets auto generated. You need to pay careful attention to the Nanite Fallback values on the meshes. You may notice that in VR and baked lighting meshes look kind of raggedy and rough like bad auto LOD. You can force the full res geo with those Nanite fallback settings if you need. I am hopeful that in 5.1 Nanite in VR will give the performance benefits of Nanite even in baked lightingā¦ but I havenāt been able to test yetā¦
To clarify:
In fact, for static lighting, Unreal uses the fallback mesh for baking the lights to speed up the baking process. The full Nanite mesh is still used in-game.
Thatās true. In my setup Nanite meshes were visible just in the left eye.
Absolutely! Iāve been working with it for a while now and it works extremely well. Not having to create LODs saves so much time. Beware that in some cases I had to re-import meshes because migrated meshes were having some lightmap artifacts.
Youāre getting acceptable performance with Nanite and baked lighting? Thatās great to hear as I knew Lumen was not going to play perform well in VR for a long time but Nanite Iām excited about. Any tweaking with console commands or just out of the box?
Thereās some overhead to account for (so thereās a minimum amount of tris under which Nanite is worse) and since light is baked against the Nanite Proxy Mesh you maybe have to tweak the fallback parameters. Otherwise itās great!
This is the only Thread I found about Nanite and VR without Lumen. So thanks for sharing some of your experience.
Some more questions:
Does it give good performance even on high resolutions and frame rates like you usual have in VR?
And how about that you canāt use forward shading and MSAA with nanite, is it still worth it?
Wellā¦ tris basically without limit is of course a huge benefit - both from a development time (no more LODs! No more baking normal maps!) and a result (endless detail!) perspective.
So yes, itās worth it. But the requirments for Nanite are such that there is a lower bound on the platforms you can use and/or you may need to make some other sacrifices (like less moveable lights) to reach your minimum FPS.
For us, forward shading was always a last resort for our projects. But it still kinda sucks not to have it as an option. In a way, the downside with switching is that youāre not going to do all the LODs/baking anymore, creating a huge barrier for moving back to regular meshes (a huge barrier created by the work that you havenāt done, that is ;)).
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Thank you for the input!
I think I will try it. I have static lighting so perhaps there is enough headroom for nanite.
Especially because I have an workflow where I process stylized high poly models in Houdini. And this would make development a lot easier.
FWIW I have finally got to do more testing in 5.1 with nanite, VR without Lumen. I got 6 billion triangles and 80 shadow casting spot lights working in VR at 60fps with virtual shadow maps. it was a very artificial test scene (a single very high poly asset duplicated many times). In a more realistic actual game level I actually had no performance increase with nanite. The non Nanite scene was reporting 4million triangles. That said, not having to deal with LOD and always getting the highest quality meshes with no LOD popping is a big deal. Using virtual shadow maps did not seems in incur too much of a burden either and gave better visual quality (though with nearly all baked lighting, this was not such a big issue).