180VR_headache

#180VR – The Good:

According to a recent article on TechCrunch, Youtube is popularizing 180 degree VR

First: The good news – proper Stereographers will be back in business and in-demand.

Now, 180 VR is not exactly something new. It’s the same as wide-angle Stereoscopic 3D movies. The quick and dirty of 180 VR – take two RED Cameras, put fish-eye lenses on them and you’re shooting wideangle stereoscopic 3d, which is being called 180VR because it’s viewed in a headset.

I’ve chosen to mention RED cameras for a few reasons, both the good and the bad. The good in choosing RED Cameras, is they are widely known for pristine image quality. The other good is a bit more technical, but it has to deal with the ability of these cameras to “Genlock” i.e, to “paint” an image across both sensors in concert; in complete sync. This is important as we’ll see in a bit.

The bad of using standard RED Cams just placed side by side to mimic the way the eyes see the world, is that the physical profile of RED cameras leads to a large interaxial (de’ja vu happening here) or to put it another way – the separation between the lens centers of the cameras is larger than our eye’s interocular distance. This leads to Hyperstereo or KingKong vision. 

If you’ve seen a VR ‘broadcast’ done by NextVR, of a basketball or football match, you’ll see how you feel like King Kong watching little human figurines running around a table top field.

There certainly are smaller profile, – closer to human interocular distance – cameras, that can genlock for wide angle stereoscopic production (BMCCs, even machine vision cameras, for instance) Sometimes it’s advantageous to have smaller than adult sized interocular spaced stereoscopic cameras.

Getting back to Youtube announcing the launch of 180 VR… it’s good but also also leads to…

#180VR – The Bad:

The video above is taken from the TechCrunch article itself, and is part of Youtube’s #180VR playlist. Here’s what Youtube has to say about it via an article on Wired:

“Watch a VR180 video on your phone, and it flattens and stretches a bit, no big deal. They look just like any other YouTube video we have on the site. So there’s no need to pan around or move your phone around. Pop it into a Daydream headset, and the footage fills your field of view.”

If only it were that easy. At least we agree, Youtube intends it to be viewed in a proper HMD and therein lies the rub:

What needs to get fixed, is this democratizing of #VR180 without Quality Checks being put in place.

Why might this lead to the delay of mass adoption of VR?… read on.

A few reasons:

  • To produce ‘true’ video based VR – it was hard, because it needed stereoscopic 360 coverage of a scene which was not easy and the forte of only a few production studios world-wide. Felix and Paul, Canada, Visualize in the UK, and the excellent work of independent producer Antonio Victor Garcia come to mind. 
  • Now, any production house can put two cameras side-by-side with fish eye lenses and claim #180VR production capability
  • Even more dangerous is the slew of cameras that will come that will not necessarily be genlock synced and allow hobbyists and consumers to produce 180VR that hurts themselves and their audiences.

Where’s the problem? Is this just a purist’s rant? No.

You_tube_180_sync_errors

#180VR – The Ugly:

The results of this seemingly “easy to produce” 180VR will lead to eyestrain, headaches and in extreme cases – nausea – and we’ll see from dissecting the sample video from the techcrunch article.

Start with the image above (click it to enlarge) – notice the foot positions of pink-hoodie’s sneaker- shift your gaze alternatively, between the back sneaker in the left half of the image and then the right – see the shuffle happening as your brain animates the image? This is because: either, the editor has messed up aligning left and right video clips on their timeline (easier to fix) or – much worse – the cameras used by the production crew were out of sync when recording this stereoscopic image. 

It’s beyond the scope of this article to delve deeper, and there’s other more specific articles on the Realvision knowledgebase (blog, to some), but what’s important to note is – this will happen more often as Quality Check will take a nose dive if even Youtube’s own studio is putting this level of material out. Hobbyists and consumers could be forgiven.

This is just one area of the ugly that could come about with 180VR…

2: Wobble Cam Nausea in 180VR:

Look at the video again – from 0:24 and even though it is a steady cam shot… remember #VR180 is to be seen in a VR headset – most likely, Youtube and Google are hoping it will be their Daydream headset.

Wobble – is magnified in VR by a factor of… I don’t know what the technical term is for measuring degrees of nausea. While it’s tempting to think 180 VR will work well for moving steady-cam like shots, and there’s reason to believe it will, we have to remember:

Even at an Imax cinema – there’s a physical distance between you and the screen. In VR – you are “in” the movie.

Watching this video, unsynced and with steady-cam wobble in a Daydream headset will make someone woozy at least and nauseated at worst – Why?

Because in VR, the wearer of the headset *is* the camera. Now, if the wearer is not bobbing and weaving – even if ever so gently – of his/her own accord, (s)he is likely to feel ill, because you, the filmmaker, are poisoning the vestibular system.

Readers are encouraged to try the video out in a VR headset (I had to download it and viewed it in the Oculus Rift)

Stereo_Jump_cut

3. Depth Jump cuts In VR = Headaches:

If you were to watch the above image with a pair of red-cyan anaglyph glasses there would be nothing wrong and it actually looks like a nice deep stereo image. However, the video is in Youtube’s 180 VR playlist and meant to be watched in a headset.

The gymnastics your eyeballs do, as this Jump Cut kicks in is not going to be easy to stomach.

To break it down: Your eyes in scene one have adjusted to a relaxed, comfortable distance, converging on the main subject – then, in a matter of a second there is a depth jump cut – the subject popping in your face (literally – as we’re viewing this in a headset) and you have to force yourself to go cross-eyed to make sense of the imagery. If these kinds of cuts happen even during the course of a 5 minute film, you can imagine what the audience will feel after they remove their VR headsets and make a mental note… to never try VR again. 180 or 360.

Now you see why there’s the Good, the bad, and the Ugly to Youtube’s announcing #180VR. 

excessive_postive_parallax

Stereoscopic Depth Continuity and Jump Cuts in VR:

Here’s a link to an understanding of Depth Jump Cuts in VR and Stereoscopic 3D and how they can harm an audience. Again, it’s bad in a 3D movie when viewed in a cinema, in a VR headset – it can cause physical harm and hurt.

Further reading:

I’ve seen footage from some of the upcoming 180VR cameras, and it’s not encouraging. One example listed, is midway through this article.

A note: 

It is indeed a thankless job to write critique, because what I get in return is: “those who can’t do, preach…” What we forget is – haters are the ones who have this knowlegebase (sorry, blog) on RSS alert and are first to visit to read, learn from, correct their mistakes, and then go on to make money from the knowledge gained, without so much as a vote of thanks, publicly.

At the very least if it leads to better VR, every one gains. When the time is right, rest assured, I’ll “do”