Someone with a little knowledge here would be greatly appreciated.
I know that it alternated the left and right eye at 180hz, but is it showing a new frame for each refresh? I was wondering if they used reprojection to achieve this?
Brainwarp in a nutshell uses an optical trick.
From what is said above 1 panel fruns at 75 to 90 hz.
1 4k image is generated 150 to 180 times. 1 eye sees the image while the other is blind. This tricks the brain into perceiving 150 to 180 fps.
For example lets say the panel has a response od 16ms. The other panel timing is set to stsrt at 8ms after the first eye revieves the image.
I understand that, but even if one eye is blind, is there other a NEW frame, a reprojected frame, or is it a copy of the other eye?
My concern is refresh rate of the physical display is arbitrary if the signal fed into it isnāt presenting new frames for each refresh cycle on the display. In simpler terms:
If you watch a 60 fps movie on a 120 hz display, the movie (without some smooth motion interpolation) is perceived at 60, because thereās no new frames to fill in every other frame on the tvās 120hz refresh rate. So between the fps signal to the display and the native display operating hz, the content is perceived as whatever is the lowest common denominator. Thatās why Iām hoping that pimax hopefully uses interpolation to add new fram3s to make 180 fps, and not simply double every frame with the same image because doubling every frame in 9p frames per second with the same image will still feel like 90.
The huge allure in whats advertised of 180hz is 180 frames per second
Does anyone know if they reproject frames to 180?.
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Okay with a tv that is using frame doubling with 1 display which is seen by both eyes.
With Brainwarp its kinda more like active shudder 3d glasses.
Brainwarp uses 2 displays. Because the eyes are rendered 1 at a time in sequence. Each eye when rendered is a complete frame.
Example
Left image right blank = 1 frame
Left blank right image = 1 frame
The brain (yours) essenitally sees 150 to 180 because display 1 refresh + display 2 = 150 to 180.
Now remove brain warp and both eyes render simultaneously thus the frames perceived beomes only 75 to 90 hz.
By rendering sequentially the brain fills in the blank from what it knows of the eye with image. By rendering display/eye at time the refresh/frames combine to create a pseudo effect on the mind. The mind sees more frames as a result. Turn brainwarp off & the mind only see max 75 to 90.
If you consider the old view master with negatives usually there is a pic with the sun present & one without. This creates a 3d effect but your mind thinks the sun is in both stills even though only 1 eye in truth can see the sun.
Simple truth we wonāt know how well this magic trick works until a combination of reviews & trying it out ourselves. If its not as good by individual preference then the team has added the option to switch it off.
Very good points, Iāve been thinking about this too and I think youāre right. Without some kind of interpolation this thing is not going make any difference.
I actually believe they ARE using shutterglasses, just like theyāre using now in the Pimax 4k. Itās the only way to have a 90hz panel display 90 frames AND 90 black images per second. Pimax said that if one eye shows an image, the other is black. So if you still want to show 90 pictures on one panel per second, you need shutterglasses to black them out after a half phase.
Still aesopfabledās point is correct I think: if both panels are just displaying an image that belongs together, without any kind of interpolation, I highly doubt that it will make much difference.
The good news is a rep told me they do infact use a proprietary reprojection algorithm. The big question is whether itās 180 frames or not. I mean, I get that the image is left eye right eye sequentially, but if itās not left eye new frame right eye new frame itās just going to feel like 90hz. So hereās hoping we get some clarification. The GOOD new is what pimax has said officially, which is they RENDER 180 frames send them in sequence left eye right eye alternating at 90 times per eye. So yes thereās a chance each frame to each eye is a NEW image, which then would mean the effect of brainwarp would indeed feel like smoothness of 180 fps.
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I know for a fact that games render the left eye and the right eye together, at once and that these belong together, so that they show the EXACT same image, just from a slightly different perspective.
I think the only way this makes sense then is that if Pimax doesnāt show the right eye like it got it from the game, but interpolates it. Because if it doesnāt, well then I agree with you that it wonāt make much difference at all.
Well, they said that they will use a custom low persistence screen. Low persistence means that the picture goes automatically black after a short amount of time. This might also be the reason why it is not as bright as other VR headsets.
But doesnāt ālow persistenceā just mean that itās a high refresh rate screen (90 hz instead of 60 hz theyāre using in the 4k) ? I think the āpersistance timeā is always the same as the interval between 2 frames ? If it would be half of that, wouldnt it be a 180 hz screen ?
No - low persistence means that the frame is shown for less time on the screen. Full persistence/a normal display would show the frame until the next frame is displayed.
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Interesting, in that case they would not need shutter technology indeed. This would then explain the better colours/brightness in the Pimax 8k.
Lol theyāre not using shutter thank goodness. My tv has a low persistence mode and does indeed cut the brightness down by about 30%, but I was able to actually counter that by adjust other features that used local dimming and even some post process stuff to get the brightness to watchable.
They are using it in the 4k, thatās why it has such horrible colours and brightness. If you remove the shutter glasses youāll need to crank down the brightness to ālow level 2ā and it will still be higher than it was with āhigh level 3ā before. It actually does what itās supposed to do though: motion blur becomes much higher after removing the shutter glass.
So yeah Iām happy to learn about this ālow persistenceā panel (I always figured this referred to the pixel response time but thatās really something different indeed, pixel response time being the time needed for the pixel to change and then the persistence being the time itās being displayed).
Anyway still leaves us with the question about brainwarp ā¦ Wish pimax would chime in and explain it for once and for all.
Could it be Pimaxās brainwarp is really the invention, or the achievement? Or maybe even the combination of brainwarp and CLPL display? When you think about it, everything else has been done, either by them or someone else. Maybe not FOV (other than starvr) but really they are just putting two 4k screens together. Iām not trying to downplay what looks to be amazing, rather Iām saying it looks like theyāve developed software to truly take care of the issues stemming from high resolution demands. This may be why they are so quiet about exactly how it works - at least for nowā¦ weāll know soon enough!
Well what Iāve heard is the whole reason this new pimax is gathering buzz is because they listened to the community and alleviated the shortcomings of the old 4k and surpassed many shortcomings of the vive/rift.
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Yeah, they are definitely listening to the community. I never owned the 4k, but have been reading all over the place about the 8k and they are replying to questions, comments, and concerns. Itās really great to see a company who may be producing the latest in vr tech to be so in touch with the consumer! This is why Iām optimistic.
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An easy way to kinda simulate the effect. Take a flipbook pad od paper draw a stick figure leave a blank page then next page start your stick figure walking repeat.
Then flip the book to animate if you flip it fast enough the blanks will be unseen.
The brain will in the case of left eye having an image the ābrainā will fill in the blank using the eye with the image from the eye that sees.
Like the example of the viewmaster having 1 pic no sun. Other eye same pic but sun at high noon.
Create a 3d effect and the eye with no sun in the brain will combine the image to have the sun seen by both eyes
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I get all that. My concern was whether if the left eye gets the first page in a flip book animation, does the second page contain a copy of the first page for the right eye or does it contain the next image to move the animation. Looking over some of there material on the Kickstarter it appears they RENDER 180 images and disperse them in sequence left right left right. Iām okay with that, as I donāt care if itās a trick to fool my visual cortex if the motion just looks smoother, itās saving a tremendous amount of processing and bandwidth.
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The game supplies 2 ācopiesā. However I THINK that their own renderer will do an interpolation on one of those 2. Otherwise I donāt think it would make much sense. In the flip book analogy to repeat 2 the same image indeed, thatās not going to make any difference.
Pimax doesnāt seem to want to explain though.