Update one eye per frame?

Since timewarp currently doesn't support movement (only rotation) moving your head would result in one eye lagging a frame behind the other eye, which wouldn't be fun.

(Even if it did support movement, it wouldn't be able to reveal previously occluded surfaces, so would still look bad if both eyes didn't do it at the same time)

Even if timewarp could account for your head movement perfectly, tracking a moving object with your eyes would be hell.

It is possible, but probably not desirable. You would end up with a 2D+depth reprojection (similar to the 3D in Crysis 2). This would boost performance, at the cost of halos around objects and other occlusion related anomalies.

We have tried it, but unfortunately what you get is the worst of both worlds - the scene still looks like it's running at the lower rate, but now there's some bizarre stereo disparity happening.

This if for the Dolphin Wii emulator BTW, if you are wondering why I want to render one eye per frame.

On a related note... if an emulator uses frame-skipping, should I be rendering the skipped frames using only timewarp? Or should I be skipping them altogether?

"2EyeGuy" wrote:
This if for the Dolphin Wii emulator BTW, if you are wondering why I want to render one eye per frame.

On a related note... if an emulator uses frame-skipping, should I be rendering the skipped frames using only timewarp? Or should I be skipping them altogether?

Perhaps it would work rendering each eye alternating at half the frame rate and fill in the skipped half-frames using alternating time-warp. If it works this could be a pretty nice universal acceleration technique.

I've got it rendering both eyes every frame now. Which works, except for screen-space effects. On my laptop, I'm getting about 1/3 the normal framerate, which is probably partly from rendering the scene twice, partly from the increased FOV, and partly from the warping. Hopefully most people have more powerful gaming rigs.

"tomf" wrote:
We have tried it, but unfortunately what you get is the worst of both worlds - the scene still looks like it's running at the lower rate, but now there's some bizarre stereo disparity happening.

I'm seeing the same stereo disparity trying this on 0.8. Did you have timewarp on when you tried? I'm seeing the stereo issue even when closing one eye, so I don't think it has anything to do with the alternating rendering of each eye. When I don't copy the last frame over for the skipped eye, it flickers black but is silky smooth, no stereo effect, so I'm guessing this is timewarp's doing and I have no way of turning it off in 0.8. I'm interested in this method as a fallback for large scenes that may not hit 75hz.