Isn't it generating in the browser using webgpu?

I mean, it's the same author but seems like co-authors are different.

How do you know it's the actual implementation?

Your link above (Splatter Image) is not the same code / paper / research as Bolt3D.

This is a previous paper/work by the lead author a year before they interned at Google Research and produced Bolt3D.

Bolt3D appears to be his intern research project done in conjunction with a bunch of other Google and DeepMind researchers.

I don't suspect there will ever be publicly available code for this.

This is previous work. Bolt3D uses the same principle, of predicting a per-pixel Gaussian splatting representation but it also trains a diffusion model, which is only feasible if you have substantial compute available.

Given that it's a work done at Google I will not expect them to release source code. But it will be reproduced by someone else soon enough.