Good answer. Especially if it could degrade gracefully for low performance, without temporal artifacts. E.g., have ray-surface hits act like point projectors with approximate visibility, so indirect lighting splashes brightness on a soft region instead of creating a hotspot.

I think there's a general solution to noise that's gone unused.

Okay, Metropolis light transport jiggles steps in each bright path, to find more low-probability / high-intensity paths. Great for caustics. But it's only used on individual pixels. It samples a lot of light coming in to one spot. We want the inverse of that.

When light hits a point, it can scatter off in any direction, with its brightness adjusted according to probability. So... every point is a light source. It's not uniform. But it is real light. You could test visibility from every hit along any light path, to every point onscreen, and it would remain a true unbiased render that would eventually converge.

The sensible reduction of that is to test visibility in a cone from the first bounce offscreen. Like if you're looking at a wall lit by the moon, it goes eye, wall, moon, sun. Metropolis would jitter to different points on the moon to light the bejeezus out of that one spot on the wall. I'm proposing to instead check moon-to-wall visibility, for that exact point on the moon, but nearby spots on that wall. (Deferred rendering can skip testing between the wall and your eye. Pick visible spots.)

One spot on the moon would not accurately recreate soft moonlight - but Blender's newer Eevee renderer proves that a dozen can suffice.

One sample per pixel could be a million.

You don't need to go from all of them, to every point onscreen, to get some pretty smooth results. Basically it's "instant radiosity" but with anisotropic virtual point sources. It's just a shame shadowing still needs to be done (or faked) or else applying them would be doable in screen space.

Honestly I'm the opposite, I want godots window manager to be more like blenders

Blender just does it so flexibly, and the minimum size of the panels isn't actual continents in size, so I can actually shove stuff out of the way that I don't need instead of having between 30%-60% of the screen being wasted at all times

Godot has improved this a bit in 4.1, since now you can pop out the scripting and shading workspace into new windows, but it's not nearly universally implemented like blender, you can't pop out the animation editor, the audio buses, the output panel, the debugger, and absolutely worst of all is that you can't pop out the viewport, even if you press the "distraction free mode" button, the bottom panel still eats like 20%-30% of the screen

Which means there's no way to quickly preview what the games gonna look like at corner-to-corner full screen without launching the game and waiting for it to load

This is even worse if you need to have multiple viewports open, because they all share that same limited space with no option to pop one out to a second monitor

GD's window manager is just incomplete compared to Blender, and I far prefer Blender's way of doing things

Godot supports .blend files check documentation