David Li is a developer who builds interactive WebGL demos, including fluid, ocean, and particle simulations, and the Blob Opera.
Commenters repeatedly call his projects amazing and point readers to his site for more demos, including the fluid simulation.
It's difficult to be sure. The original study was posted a few days ago, and my impression is that it was over hyped, more overhyped than the usual level. The article claims:
> The paper is extensive, with dozens of experiments replicated at multiple sites around the world.
but it has not been reproduced by independent groups and IIUC it's just a preprint that has not been officially accepted by a serious peer review journal.
About grey box, they are using a high pass filter, and put the zero in grey, something like #808080. With a high pass filter you should be able to see all the borders of the parts of the body, but sometimes the constant is low. So for a person it looks like grey, but a computer can adjust the contrast and see it.
For example, you can go to https://david.li/filtering/ and click the "Edge detection" filter. Now imagine reducing the contrast of it, and using grey instead of black for 0.
I'm a fan of David Li's work[0]. Most recently he created the Blob Opera[1] which builds up of a lot of his previous experiments
As for recreating some of this work, you could probably start by looking at his github repos[2].
[0] http://david.li/
[1] https://artsandculture.google.com/experiment/blob-opera/AAHWrq360NcGbw
[2] https://github.com/dli
GPUs can definitely handle more than 700 entities. Here's 100k in a web browser: http://david.li/fluid/
But even most offline rendered fluid simulations are not that convincing to my eyes, let alone real time ones. It will be a long, long time before we have truly realistic behavior of real time water in unconstrained settings for games.
There is also a follow-up demo by the same author called Disintegration, with skinned animated mesh driving particles:
http://david.li/disintegration/
That one is brilliant - I just realised you can change the light direction.
Another classic: http://david.li/fluid/
The 1D-case for edge filtering is already quite impressive, when done interactively.
http://david.li/filtering/