I reckon that at the current polycount of today’s games an Nvidia Pascal by the ~end of 2016~, say the GTX 1080 Ti ~will~ be able to run 4K with 90fps with VR with VXGI. At least the Nvidia Pascal Titan Y or whatever they might call it.
So the very high-end Nvidia cards of 2016-2017 I believe will handle 4K VXGI VR at high frame rates, particularly with improvements to UE4, VXGI and the drivers. Not to mention tons of optimisations being done for VR right now including Nvidia’s GameWorks VR efforts like “crushing” the edges of a scene (https://www.youtube.com/watch?v=1Dn2JKfje2o).
You rightly point out the issue of the next five years for mainstream PC gamers. I’m still learning UE4 so from a layperson PC gamer perspective indeed it’s great if developers can “fill in the gaps”.
What’s been brilliant about PC game developers is the scalability they’ve (almost) always implemented in games. I’ve always enjoyed how you could play through a game at low, low settings and still get a feel for it, while gamers with the top-notch equipment enjoy all the maximum graphics possible (“really bad console ports” not included, of course).
Can you share how you are working with the scenes with VXGI on and off? I think that’s a very noble approach to this whole matter. What’s the method to toggle “force no precomputed lighting” on and off at runtime? I think that’s a better approach than trying to use really low VXGI settings for low-mid GPUs.
So to sum up, at the end of the day the effort in making a game that has VXGI and non-VXGI all-in-one can pay off in terms of advertising and marketing opportunities. The game could (rightfully) be shown as, hey, this is how it looks on mainstream graphics cards (and it should still look good), but then, BOOM! with an Nvidia Pascal and better check out full dynamic GI with VXGI. Yes, it goes back to the controversial “The Way It’s Meant To Be Played”… but if you’re a game developer trying to deliver the best experience for gamers, as long as the experience for mainstream Nvidia and AMD is good and not purposefully crippled, why not? I don’t know the industry but I suspect incorporating UE4, VR and VXGI in any game in the next five years will get a lot of support (and let’s be honest, free marketing) from Epic, Nvidia and Oculus.
So all the best, you’re at the very cutting edge and potentially looking at good rewards for your efforts, Lord willing! (That said, there is a very dark side of people being lost in photorealistic VR and not being able to adapt back to the real world… but that is something I suppose an individual developer has to consider themselves).
PS. As for VR Oculus has already specified (IIRC) the Nvidia 970 as ~minimum~ …So for PC VR we’re already in high-end Maxwell territory. Obviously at this point VXGI is not suitable for Maxwell VR, but high-end Pascals should be capable as I detail (estimate) above.