In general, when "you" do things in VR that you'd normally expect strong feedback for in your head, and you don't, you feel sick.

Some examples: strafing side to side (try it), going up stairs, any sort of sudden acceleration.

Vive avoids this in room scale VR since you receive the feedback since you're really doing the action.

The best demo/test I've come across for this is Minecraft in VR for the Occulus Rift. It has a "theater"-mode, in which you can play Minecraft on a "big screen" in a room in VR. This mode works great for running around and doing things. And it has a first-person mode, which works great -- for standing still and looking around. But I'm pretty sure the only people that can play and walk/run around in first-person mode, are the 0.5% of US fighter pilots that don't get motion sickness at all.

I think it's a great way to demo the limits that motion sickness places on experiences for the vast majority of people. It's more than just being in control, and there are other effects at work, just like hand-held video footage without image stabilization is painful to look at. But my pet theory is that the big one is working with your body - if your body sits in a chair, your avatar should too (ie: drive a car, fly a spaceship is ok, walking around an art gallery at a leisure pace, not so much).

It's likely he played entirely different demos between the headsets, which is a huge factor in whether one gets motion sickness.

Probably because of the full room position tracking and using teleportation for longer distances instead of a controller. If the viewport/camera moves but your body doesn't move you may experience motion sickness.

I suspect (speculate) that the issue is with normal vision being a sequence of saccades, wherein you don't actually see anything between point A and point B, vs most VR which is a smooth glissando between points.

I heard of one hack, for minecraft or something, that snapped view angle increments to 30degrees or something like that, and it was helpful. That would simulate saccading.

Expect a lower point of view frame rate (vs animations that don't change point of view) would be helpful. i.e. smoothly move whatever is in your hand, or that pig on the landscape, but turning your head triggers saccade emulation.

> I suspect (speculate) that the issue is with normal vision being a sequence of saccades, wherein you don't actually see anything between point A and point B, vs most VR which is a smooth glissando between points.

Why would your eyes not saccade when wearing a VR headset? The screen isn't the source of saccades. Your eyes are.

because your eyes are looking straight ahead for the most part. It's like seeing the world through a narrow view point like binoculars (sans magnification).

You can dart around within that narrow window, but mostly you are looking around by turning your head. You are subjected to more visual motion than you would in real life.

Your eyes still saccade when you turn your head. If your headset is causing your eyes to stop saccading properly, I'd expect that means it's not rendering fast enough. I also don't see how adding jitter to the turning would fix this. That seems like it would just cause major disorientation. Maybe I'm totally off though.

I was at the mall and had a chance to try out an occulus rift. It was a very pleasant surprise. My speculations were completely wrong, it felt very natural.