How does the render chain work – Tips for optimal setting

[Wehrwolfi]

Hi Vorpx lovers !

I’m a recent Vorpx user and tested it so far only with a few games, maybe not the best ones as they are not officially supported (Far Cry 5, Guardians of the Galaxy).
Although the result is great and in some cases really near to my 1080p physical display, letting me use the headset most of the time.
I play mostly in Immersive Screen for those games without head tracking, so basically, I mainly use the stereo-3D function as I would have done with Reshade+SuperDepth3D in the past.

My headset is Pico 4, I connect through Virtual Desktop, my GPU is RTX 3090.

I found that the best graphical quality was achieved with those settings :
– Games resolution the higher possible (over 4k resolution I don’t find that much difference and performance decreases a lot)
– Play through steamVR mode instead of just Generic 3D Display (then Virtual desktop SBS desktop mode). Because VD is capped at 1440p…
– VD setting in Godlike (3120×3120), HEVC-10 codec, max bitrate.

What I would like to understand is how the render chain is made to find the “sweet spot”.

First step is the game itself : setting the higher resolution improves the quality and sharpness, making the use of AA unnecessary.
I would tend to say that here the higher is the better.
Then Vorpx :for example, in my case, if I don’t run the game through Vorpx virtual screen, then 4K resolution will be in fact DSR. Does Vorpx “grab” the output at 4K before downscaling to 1080p ? If yes, we benefit from DLDSR a bit. If not, it would be better to use custom 4K resolution on virtual screen.
Then SteamVR : renders at 3120×3120 because of VD Godlike setting. Don’t know if I should put a manual value there? Maybe the same as game resolution?
Then Virtual Desktop : takes the output from SteamVr, encodes it and sends to Headset, then decodes it in Standalone and updscales/downscales to headset resolution, with barrel distortion etc…

So, there is a whole chain of conversions involved there. I would like to get your advise on what could be a common guideline to set it up. Is simply the higher resolution at all steps the best if the computer can manage it? Or should we try to align everything on same value to avoid upscales/downscales etc?

Thanks in advance :)

[Wehrwolfi]

Additional questions if you don’t mind :
– I would like to try mixed reality in VD to replace the black environment aroud the Immersive screen with passthrough. Then I would find back the essential function that I miss with VD Desktop view. Did someone try ?
– I’m also open to any suggestion for 4K movie watching. is it better to simply watch them through DeoVR or similar app on standalone headset or through Pc with Vorpx? Then what is the best setting ?
On my TV I had a whole set of settings and filters with MADVR etc… don’t know if they would apply in this context.

[MarcDwonn]

Couple notes:
– VD desktop streaming is now 2160p since v1.29.6 (VD Classic, the Steam version, has an uncapped resolution IME, but you need to set resolution on your monitor first)
– Watching movies is easiest with VD – just stream them from your PC and play them with the VD player. If you want postprocessing, you can play the videos on PC full screen and watch them in VD desktop mode.

[Wehrwolfi]

Hi MarcDwonn, thank you for your answer.
How do you activate 2160p on VD? I’ve never seen this info and when I even use Virtual Desktop own virtual screen adapter (unplugging my physical screen), the max resolution is 1440p.
EDIT : looks like the 2160p res. is only for Quest 3 headset, lucky them ! I understand better now how they could say that they achieve similar quality than physical display.

For movies I have to do my own testing. I didn’t find yet a satisfying solution that would make me stop using my TV (also because of the great colors and contrast it has!).
But I red somewhere that Vorpx takes the output of video player (like MPC-HC) before the post-processing is applied.
Also, if VD desktop view is 1440p, the result is worse compared to Vorpx and maybe worse compared to standalone apps.
To be continued…

[Wehrwolfi]

After further testing I can confirm that it’s possible to activate VD mixed reality mode when setting a solid colour backround in Vorpx Cinema mode. This way, the passthrough is here also in SteamVR!

From a quality point of view, VD limits the Quality setting to High with Mixed reality mode activated (means 2520×2520 in SteamVR). I then tested it against Godlike and wasn’t seeing big difference even lowering in-game resolution to 2560×1440. I’m quite confused about all those resolution things and it’s quite hard to do a side-by-side comparison.

What I can confirm is that the picture quality is still better in SteamVR with equivalent resolution. That could mean that the difference comes from VD Sharpening and color enhancements that are not activated in Desktop mode?

[Author]

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