SSAO and VR

[jjensson]

In preparation for buying my 1st VR headset (Rift S) i’m doing my homework and watched the VorpX tutorial by Stereo3DProductions.

I was shocked when he explained that you have to turn SSAO off for VorpX! That would be a complete dealbreaker for me, as i can’t play a game without ambient occlusion – switching off AO completely destroys the lighting IMO (i’m extremely sensitive about lighting in games – it’s my #1 immersion requirement).

Could anyone please share his knowledge about this issue? Why should i disable SSAO in a game with VorpX? Is it just a performance problem, or are there artifacts? What kind of artifacts? Would an ENB help? Are games with HBAO free from this issue?

Unfortunately there is not much information available about this…

[Ralf]

Whether that statement is true or not depends heavily on the game and how you use vorpX. Fore some games SSAO works perfectly fine no matter what. For others it may not.

With Geometry (true) 3D it can make sense to disable computationally intense effects like SSAO to get a VR compatible frame rate alone. Keep in mind that vorpX needs to render everything twice to make a game 3D, which cuts your framerate in half. On top of that there is some extra overhead for rendering the image to the headset.

Screen space effects of all kind may also not work correctly in (geometry) 3D since normal games aren’t made with stereo rendering in mind. Depending on the game that might be another good reason to disable them.

However, for most games vorpX also has a less demanding post process stereo creation method. The stereo 3D effect with this method isn’t quite as natural as the Geometry 3D method, but it’s a lot faster and doesn’t come with any drawbacks regarding screen space effects like SSAO. Most prefer Geometry 3D, but if perfect SSAO is the most important thing to you under all circumstances, this depth buffer based 3D method is practically made for you.

[jjensson]

Ralf, thanks for the fast reply. How about a more concrete inquiry: My main wish is to play the Witcher Trilogy in “VR”. Maybe you could elaborate quickly how the issue lies with these 3 games (or probably Witcher 2 and 3, because the 1st one doesn’t have AO, AFAIR). TW2 has SSAO, TW3 has HBAO. Any insights how they work in Geometry 3D with enabled ambient occlusion?

Performace is really secondary for me. In the past i’ve played games with under 20fps and i’m still alive. :) If needed i’ll buy the fastest VGA card available just to be able to play the Witcher Trilogy in “VR”.

[Ralf]

Performance may be secondary for you while you play games on your monitor, but it won’t in VR, trust me. Can’t relly recall TW2 currently. G3D in TW3 works well enough I would say, but there are some shadow glitches with G3D. If you can’t live with something like that all (or with disabling effect options if necessary), Z3D is your way to go.

[jjensson]

Thanks. I’ll research the topic G3D vs Z3D if that’s the most safe route for a glitch free experience. Otherwise it’s “wait another year” i guess. I waited 4 years for VR, after the Oculus announcement, i can wait a bit longer, until most of this stuff is really fixed.

You see, i’m not interested in those new VR games at all. All i want to do is experience the best of the best (IOW, older games like Witcher) in VR, in all their graphical glory. For that, i would even pay 100€ for VorpX, if all the lighting works glitch-free in G3D.

[jjensson]

Quick follow-up: I crawled the forum for information and it seems that Z3D perfectly usable for many games. I had the fear that it will brake immersion, but now it looks to me that all the lighting problems in G3D would be more immersion-braking to me.

It’s an acceptable compromise, given that these games are not made with VR in mind. I think i’m sold now. :)

Can’t wait for the Rift S to hit the market.

Ralf, i hope i have not sounded too negative previously. VorpX is a dream come true for me, and the thought of compromising visuals for working stereo3D always made me sad. As it stands, the software is mature enough for my needs, and i can’t wait to test it out in the next months.

Thanks again!

[dellrifter22]

Not to say the Rift S would be a bad choice (especially at that price point), but one might also consider other headsets scheduled for this year. Valve just announced the Index, HTC VIVE Cosmos is said to sport their highest resolution yet, and the HP Reverb with an impressive 2160×2160 per eye.

As one who uses my headset almost exclusively for vorpX, and cares less about trackble hand controllers, the Reverb has my attention. Current VR can’t yet match the image fidelity you are used to on a monitor, so I’m excited to see higher resolutions coming.

Z3D is my preferred option for 3rd person games anyway, as it preserves the native look of the game (i.e. shadows and lighting) and also let’s you run higher resolutions with the extra performance headroom. Only real drawback you’ll notice is objects closest to the screen will have a slight transparent outline and may look a bit flatter than expected (i.e. in dialogue closeups), but the over all scene will have compelling depth.

G3D is preferred for first person games and looks the best close up, but will often have compromises with lighting/shadows. Something that bothered me more initially, but I’ve became more accustomed in some cases.

[jjensson]

Great post, dellrifter. Especially those infos about Z3D vs G3D.

The only question mark for me ATM is the Index. It could change my plans completely, but we’ll see. The problem with the other HMDs you mentioned: As much as i don’t care about proper VR games ATM, i’m still interested to play some of the narrative titles like Lone Echo or Stormland, and i don’t think that i could live without SkyrimVR. :) So that’s the reason for Rift S. Besides, after all i’ve read, Oculus HMDs tend to run better and more reliable w- VorpX than SteamVR and WMR stuff. :shrug:

PS: One other consideration is health. I’m sitting way too much every day, and i figured that a HMD will allow me to play standing, so motion controllers (with gamepad emulation) may be better suited than an XBox or Steam controller.

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