The Kawase approach is from 2005, and GPU performance has improved a ton since then. Some of the newer games do use Bokeh blurs with multiple depths of field. The result can look much more natural than the Gaussian stuff. BTW, it's not just a cinematic effect -- the fact that our pupils are round means that like cameras, they act as a disk-shaped filter for things that are out of focus.

Here's a breakdown of how Doom (2016) does it: https://www.adriancourreges.com/blog/2016/09/09/doom-2016-gr...

I'm a huge Adrian fan boy <3

Yes, bokeh blur is way more pleasing. In my article the gaussian likes are the focus for their use as a basic building block for other effects, like frosted glass, heat distortions, bloom and the like.

Specifically the 2015 Dual Kawase was created in the context of mobile graphics, with weak memory throughput. But even on my RTX 4090, near the fastest consumer hardware available, those unoptimized unseparable, naive gaussian implementations bring it to a crawl and `samplePosMultiplier` has a non insignificant performance hit, so texture caches still play a role.

At today's high resolutions and especially on mobile, we still need smart and optimized algorithms like the dual kawase.