There's a similar effect in old movies when a super-strong character picks up a massive boulder that is actually made of styrofoam or something. You can tell that the mass is wrong based on the way it moves.

I think this is a similar effect but in reverse -- we know the limbs are heavy and aren't made of styrofoam, so the fact that they are moving like they are is uncanny. Our brains aren't used to motorized and hydraulic limbs.

You can get a little bit of this effect watching assembly line arms sometimes, but it's less jarring because they are clearly disembodied, whereas this thing is fairly humanoid.

Or even in modern movies with CGI-enhanced characters.

Gollum moves as if his enormous head was empty, because the actor doing the motion capture didn't wear a heavy helmet.

In "Rust and Bones", Marion Cotillard plays a character that loses her legs after an accident, and she has her legs removed by CGI, but there are scenes where she's carried by Matthias Schoenaerts that look unnatural, out of balance.

I see this frequently even in newer movies/tv--when actors are drinking out of empty coffee cups.

That's a great example. I wonder how much of that is due to the (lack of) the weight of the coffee, vs. not having to compensate for sloshing liquid that could spill if you aren't careful.

Could it be slightly sped up? The robots do make jumps so one could calculate it from that.

I was curious so I just timed the jump at the beginning of the song about 15 seconds in.

Assuming the jump is about 30cm, and I stopwatched it at 0.3 seconds from the apex to the ground, you arrive at an acceleration of 9.6m/s^2 which is basically spot on the acceleration due to gravity.

At 0:57 the camera pans to a position where you can see people on the upper floor walking by in the distance. You can see them move as the robot dance, which shows the video is not sped up. You could claim they were composited in (a suicidal move for BD, if they ever tried that), but if you look closely at the windows below, you can see the the camera crew in the reflection, who also move at the correct pace - and that shot would've been hell of a work to fake. In conclusion: this is real-time.

I think it's clearly recorded in-camera, and I think real camera footage - the reflections in the (plexi?)glass screens show the robots and people holding cameras. I'm not even seeing any obvious indications it's been denoised.

As someone who works in the VFX industry, faking reflections on wobbling/flexing glass screens (static ones are easy) is actually pretty difficult to do right, and I doubt they would have added the camera operators if they were faking it.

Some of the aspects making people think this is CG are the diffuse lighting (no obvious hard shadows or occlusion), very clean robots, "weird" (i.e. not normal, but I believe it's honest for the robots) motion, and lack of sound.

I think what happened is they used a fancy camera with a big lens and a 30 FPS frame rate, giving a very high quality image reminiscent of Hollywood films, but they set a faster shutter speed than Hollywood generally uses, giving less motion blur than is normal in high quality footage like this. The relative lack of motion blur despite the low frame rate gives it a jerky appearance similar to sped up or timelapse video, or animation. Combined with the slightly odd motion of the robots, it has an uncanny look.

It's kinda funny because most robot demo videos are sped up and/or CGI, but this one isn't.

You can see the vibrations of the plexiglass walls and the camera crew reflected in them vibrating in amazing detail. You can also see people walking around in the background in normal speed. It doesn't look like it's accelerated, or I would say no more than 10%. Also given the visible but subtle marks the robots leave on the mat, this is either next level CGI and compositing or next level robotics, and BD are not a next level CGI company.

I think it's absolutely fascinating that so many people, here and especially in the YouTube comments, are thinking this is CGI, when doing this with CGI would be much harder than doing it for real.

Also, if you've followed Boston Dynamics for a while, what this video is showcasing isn't that much of a leap forward, they're just iterating away on their robots, adding capabilities and movement patterns.

I'm inclined to agree with this after bumping the video up to max quality. I do believe that this is real, and you can see from 0:51-1:05 that there's some reflections going on that would be a lot trickier to fake. But this footage has a similar quality to what I see in a lot of heavily processed drone footage, where it just doesn't look like the same way I see the world.

Also watch their feet very closely at max resolution.

There's a lot of shock rattling and wobbling I've never seen in any CGI robot animation, not to mention they are leaving visible indentations in the foam floor. If it was CG they really went all out.

If you look carefully, you can also see reflections on the robot's visors.

Change playback speed to 50% and it looks more realistic. That's probably realtime and they sped up the video.

I don't know... watch the people walking in around 1:00 in the top left. Looks pretty much real time.

https://youtu.be/fn3KWM1kuAw?t=58

A simple test shows this isn't more realistic. Gravity during the jumps are off, and people walking upstairs is odd. It looks like it was filmed in realtime.

75% looks most similar to the previous Atlas videos. Also the movement of the people upstairs behind the glass or the reflections of the cameraman confirm that it has been sped up.

I don't know how fast you walk, but at 75% those people are definitely in slow-motion. I could see maybe 90%, but 100% looks completely natural to me as far as their movements are concerned. (Personally, I want to see a jump at 90% to judge, not someone walking.)