Ryan James Smith, Lead Technical Artist for Sony Santa Monica, who works on the critically acclaimed God of War videogame series, has shared a video of a "physically accurate black hole with volumetric accretion disk."
The impressive render was created using the popular game engine Unreal Engine, first developed for 1998 videogame Unreal by Epic Games.
Unreal Engine rendering black hole realism
Smith shared an early render of the black hole model on Twitter on October 5, stating that he was "working on a physically accurate depiction of a black hole with proper gravitational lensing" using Unreal Engine 4.
Working on a physically accurate depiction of a black hole with proper gravitational lensing in #UE4. Next Steps: Volumetric accretion disk, gravitational and Doppler redshift, and improved gravitational distortion caused by the spin.#gamedev #UnrealEngine pic.twitter.com/ukcCXj7w1O— Ryan James Smith (@OverdrawXYZ) October 5, 2020
The next steps, Smith said, were the volumetric accretion disk, gravitational and Doppler redshift, and improved gravitational distortion caused by the spin.
In the real universe, the accretion disk — viewed in that famous first image of a black hole from last year — is formed by diffuse material, often remnants of stars, orbiting the massive black hole.
Doppler redshift, meanwhile, is caused by the change in wave frequency of light from a black hole due to our relative motion away from the source, making it appear red.
'Better than anything I've seen in games'
Ryan James Smith's final render is an impressive sight, to say the least. Have a look at the model in motion in the video below.
Physically accurate black hole with volumetric accretion disk, made using @UnrealEngine . Black hole spin warps space time, causing further space warp and doppler shift of light, present in the video (Spin = 0.4). #UE4 #madewithunreal #BlackHole #gamedev pic.twitter.com/1gYzx6yXE9— Ryan James Smith (@OverdrawXYZ) October 13, 2020
One commenter, Scott Manley, did mention that they couldn't make out the differential rotation in the accretion disk, or the transverse Doppler shift, prompting Smith to say:
"At 1:11 I start to adjust the spin parameter which makes the doppler effects a bit more apparent. The shadow hides some of the redshift that's happening. It's an approximation. I regret saying it's "physically accurate."
This is, nevertheless, one of the most impressive 3D models of a black hole we've seen. It even rivals some of NASA's most impressive 3D visualizations. As Manley says, "it still looks way better than anything I've seen in games."