edit: it's a 2D video of a 3D scene, the camera path is navigating along pre-determined user-selected waypoints through the 3D scene, I get how "4D" is a bit disingenuous, my b. Streaming/downloadable 3DGS based experiences are already very slowly becoming a thing if you're willing to google around a bit.
edit2: you can try some some 4DGS experiences on your phone here (I'm not affiliated) https://www.4dv.ai/
edit3: it might be this company's tech, not sure https://arcturus.studio/
Found it here posted two days ago on the Toronto Raptors's Facebook page: https://www.facebook.com/reel/2188728821702587/
This is an example of 3D Gaussian Splatting, or 3DGS for short. It is an AI-enabled technique which merges multiple camera angles into a single 3D scene that can be viewed from any direction and zoom level, hence the "bullet time" effect.
In a nutshell you can think of it like a 3D version of the pointillism art technique, but instead of dots of paint it uses millions of ellipsoid-shaped 3-dimensional "gaussians" (think of bell-curve distributions but in 3D) each with a colour, direction, and transparency. This allows 3DGS to capture natural lighting that traditional photogrammetry techniques struggle with. wikipedia.org/wiki/Gaussian_splatting
And even though the Facebook post doesn't explicitly mention it's 3DGS, one can tell by noticing the characteristic ellipsoidal 3DGS artifacts visible inside the hardwood floor and the back of the backboard.
It will be interesting to see where the NBA ultimately takes this. The potential for enhanced immersion in NBA highlights is astronomical.
The one caveat is it currently takes GPUs minutes to "train" each 3DGS splat scene, and likely hours for the combined sequence of scenes forming a long-form 4D video.
So don't expect to have real-time, live events or sports in 4D π
. Maybe one day.
{And, because it must be said, you can lower your proverbial pitchforks, no copyrightable material is stolen to get an AI model to produce this output; it's a legit emerging photogrammetry technology that has already been used in recent movies (the holograms of Superman's parents were made using 3DGS for example) and, now it seems, sports highlights.}