Comment by keyle

I know this comes up a lot on HN because its not primarily a graphics community but:

1. Gaussian Splats are very expensive to render. They capture a lot of detail which makes them seem cheaper than an equivalent raster render of that quality, but they wouldn't meet real time AAA game performance requirements

2. Gaussian Splats don't have a concrete surface. Want to cast shadows or do physics? It's doable but very tricky. Want to relight them? Also tricky. What is the exact surface point that you want to affect or sample for any particular operation? Deformations also become very difficult to do well.

3. Gaussian Splats are not sharp. You can get sharper with different kernel types or higher density of points, but your costs go up as well.

4. Gaussian splats are awful for any kind of path tracing. You can do it but you go back to the issues above. So mixing and matching traditional content with splats becomes a performance bottleneck.

I don't think you'll see a AAA game use splats for more than something like cinematics in the near term.

Note that the first published work of rendering Gaussian Volumes was in this 1991 paper (https://articles.tomasparks.name/publications/Westover1991.p...) - so 3DGS is really a rehash of an old method from the 90s!

The contributions of 3DGS lie in how fast you can make them in modern GPU hardware (tiling + sorting with threads), and how to make the pipeline differentiable so that you can fit the Gaussian splats with photogrammetry data. Similar to the history of deep learning, it became technically feasible once the GPU hardware was powerful enough.

There was this FPS demo recently https://playcanv.as/p/qxGSuzYq/

People have also converted some small sections of Unreal 5 demos into splats https://superspl.at/scene/692c4f91

Or perhaps use a real world scan - it was suggested this one would make an ideal setting for zombies https://superspl.at/scene/6359774f

Many years ago there was a game called Casebook[1], a small little detective game where you investigated rooms for clues. But unlike similar FMV games where you jumped from point to point, it had photorealistic environments that could be smoothly walk around in, much like later lightfield or gaussian splatting experiments.

[1] https://www.youtube.com/watch?v=o-VAaC5BgVE

It's not gaussian splatting, but Outcast (1999) has an interesting voxel-like rendering for the world surface. It has a pretty distinct feeling when walking around in the early areas, and a somewhat clunky but usable UI.

> The game does not actually model three-dimensional volumes of voxels. Instead, it models the ground as a surface, which may be seen as being made up of voxels. The ground is decorated with objects that are modeled using texture-mapped polygons. When Outcast was developed, the term "voxel engine", when applied to video games, commonly referred to a ray casting engine (for example the Voxel Space engine). On the engine technology page of the game's website, the landscape engine is also referred to as the "Voxels engine". The engine is purely software based; it does not rely on hardware-acceleration via a 3D graphics card.

https://en.wikipedia.org/wiki/Outcast_(video_game)

This is "rendering a 3D world". It's basically the exact same techniques that traditional rendering uses, just with a different primitive that's not triangles. Everything else pretty much carries over.

If you mean the technique of splatting specifically, Dreams for PS4 [1] is prior art.

If you mean pre-rendering, there's Myst and games like the original FF7 for PS1.

[1] https://en.wikipedia.org/wiki/Dreams_(video_game)

Dreams for PS4 used point splatting and has a very unique look as a result. The splats were created from distance fields instead of being scanned, so they don't look like modern gaussian splats. They have a painterly look instead. https://youtu.be/2ltgkcoQzow

Bladerunner: Revelations used a similar technique to bake down large CGI worlds with expensive lighting into something that ran on a Pixel 1 at VR specs.

Its honestly really very hard to work with this stuff because you ultimately need to be able to meshes inside these scenes triangle seas and you need to do it in a way that plausibly fits in the world. You can't have unlit characters walking around a baked lit scene and have them fit in. That's just from a visual design perspective.

You also always want to have bounce light from your dynamic things onto the baked scene and depending on the tech, you might not even be able to spatially place a dynamic thing and have it properly occlude what splats it needs to occlude.

As is, its a niche technology for games. That might change one day.

https://github.com/googlevr/seurat https://www.youtube.com/watch?v=Pf5Q3bvXj8E

I think it's inevitable it goes there. Right now the level of detail and quality of games is limited by the console/PC hardware you're playing on. But with the splats they can render the whole game's world in a massive server farm at Hollywood Movie quality. I imagine there might be some balance of splat and traditional rendering technology since not all objects will lend themselves well, but this might be truly transformative.