It’s beautifully done. A few questions
I noticed that complex patterns - marble, some paintings, some stained glass - are rendered in what seems like stretched, hazy ellipses. Is that the fundamental building block of a splat?
Also, I was interested if any specularity would be captured by the splat. Or any other aspect of the building which shifts from viewpoint - like lights reflected on the marble floor, or where a metal element outdoors is reflecting the sun but only from one vantage point. I didn’t see that. As I understand it, splats are a kind of solution to the “problem” posed by the series of photos so they are capable of capturing that sort of thing. Is that present here, and I missed it? Or is that something that you need a lot of processing power for, to generate a more complex solution for the light fields?
Splats can indeed come with view dependent colors to represent lighting, reflections… Those are captured in values called spherical harmonics of different levels 0, 1, 2, 3 representing different aspects like diffuse, directional lightning, highlights… Not all splat reconstructions come with spherical harmonics though. And they add rendering overhead.
Besides spherical harmonics splats are also good at representing high frequency detail that is harder with traditional meshes: Hair, clouds, vegetation… notice how trees in these reconstructions already look much better than in google maps / earth 3D views.
The ellipsoids are what a splat renderer uses as primitives, usually.