AA vs downscaling from higher resolutions
I think it might be a good idea to re-open this discussion as there seems to be a fair amount of friction between those that find that downscaling from 1920x1080 is an acceptable way to improve image quality in the Rift vs those that find it unacceptable and comes with a potential increase in latency.
With Unity, I've explored a multitude of options:
1) No AA, using native Rift resolution of 1280x800.
2) No AA, downscaling from higher resolution.
3) Anti aliasing as a post effect, occurs after lens correction and chromatic aberration
4) AA between lens warp and chromatic aberration correction.
5) 2x/4x/8x MSAA via Unity's quality settings
Note that at this time, the #5 option here does not actually function like UDK's ScreenPercentage setting because the MSAA textures are not yet accessible. I'm guessing that when Unity does support this, the quality settings are all that we'll need to get a simple and effective "ScreenPercentage" setting in Unity.
Also note that at this time, the #4 option is not possible unless we make some significant changes to the Oculus Unity integration (and I personally haven't taken the time to try out a proof of concept).
So for the time being, that realistically leaves us with #1 (No AA at 1280x800), #2 (No AA, downscale from higher res), and #3 (AA using one of Unity's several AA image effects), and maybe even a combination of these.
Here are screenshots taken of some text that does not squarely face the user, although the user is looking directly at it. The text should read "0%":
1280x800 (No AA, 4xMSAA, postwarpAA):
1600x900 (No AA, 4xMSAA, postwarpAA):
1768x992 (No AA, 4xMSAA, postwarpAA):
1920x1080 (No AA, 4xMSAA, postwarpAA):
My conclusions:
1) I find that post-warp AA done as an image effect softens up the scene details too much, darkens it, etc. Not acceptable (and also has a not insignificant hit to frame rate).
2) I don't see much difference in legibility between no AA and using 4xMSAA in Unity's quality settings, so might as well not use it in favor of performance, although one could definitely make the argument that straight edges would benefit from it.
3) The higher the resolution the better, and even running at 1768x992 looks like it starts to provide acceptable readability of that "0%".
4) I don't have a way to test the latency difference between native 1280x800 and downscaling from a higher resolution, but it sure doesn't seem to feel any different to me, even with looking around all over the place real fast like a crazy person.
Therefore, until Unity allows access to MSAA textures, just use as high a resolution as you can? :)
With Unity, I've explored a multitude of options:
1) No AA, using native Rift resolution of 1280x800.
2) No AA, downscaling from higher resolution.
3) Anti aliasing as a post effect, occurs after lens correction and chromatic aberration
4) AA between lens warp and chromatic aberration correction.
5) 2x/4x/8x MSAA via Unity's quality settings
Note that at this time, the #5 option here does not actually function like UDK's ScreenPercentage setting because the MSAA textures are not yet accessible. I'm guessing that when Unity does support this, the quality settings are all that we'll need to get a simple and effective "ScreenPercentage" setting in Unity.
Also note that at this time, the #4 option is not possible unless we make some significant changes to the Oculus Unity integration (and I personally haven't taken the time to try out a proof of concept).
So for the time being, that realistically leaves us with #1 (No AA at 1280x800), #2 (No AA, downscale from higher res), and #3 (AA using one of Unity's several AA image effects), and maybe even a combination of these.
Here are screenshots taken of some text that does not squarely face the user, although the user is looking directly at it. The text should read "0%":
1280x800 (No AA, 4xMSAA, postwarpAA):
1600x900 (No AA, 4xMSAA, postwarpAA):
1768x992 (No AA, 4xMSAA, postwarpAA):
1920x1080 (No AA, 4xMSAA, postwarpAA):
My conclusions:
1) I find that post-warp AA done as an image effect softens up the scene details too much, darkens it, etc. Not acceptable (and also has a not insignificant hit to frame rate).
2) I don't see much difference in legibility between no AA and using 4xMSAA in Unity's quality settings, so might as well not use it in favor of performance, although one could definitely make the argument that straight edges would benefit from it.
3) The higher the resolution the better, and even running at 1768x992 looks like it starts to provide acceptable readability of that "0%".
4) I don't have a way to test the latency difference between native 1280x800 and downscaling from a higher resolution, but it sure doesn't seem to feel any different to me, even with looking around all over the place real fast like a crazy person.
Therefore, until Unity allows access to MSAA textures, just use as high a resolution as you can? :)