Show HN: Immersive Gaussian Splat tour of grace cathedral, San Francisco (vincentwoo.com)

Hi Vincent, the Sutro Tower 3dgs demo is one I enjoyed a lot. I'd whip it out on my phone and show people saying, 'hey look this is whats possible with 3D Gaussian Splatting'. And this Grace Catherdral splat is stunning. It showcases one of my favorite parts of 3dgs which is reflections and glass. The color and essence of the stained glass comes through so well.

The cutaway Peek feature is like a sci fi version of an Stephen Biesty's Incredible Cross-Sections book. Incredible work!

Very impressive. How are you managing to produce such a clean model without artifacts?

Extraordinary. Thank you for sharing. If there would ever be the possibility of seeing European Gothic cathedrals in this manner, that would also be really cool.

From OP's prior work scanning Sutro Tower in SF: https://vincentwoo.com/2025/02/18/sutro-tower-in-3d/.

> This scan is made possible by recent advances in Gaussian Splatting. This is an emerging technology that lets us quickly create very detailed models just from photographs. For this model (or splat, as we call them), my friend Daylen and I flew our drones around Sutro Tower at a respectful distance for an afternoon until we had collected a few thousand photographs.

> I then aligned these pictures in free software called RealityCapture. Alignment is the process that teaches the computer that a bunch of points in different images all actually correspond with the same point in real life. Then I used another piece of free software called gsplat to produce the 3D model itself.

I'm assuming this was done similarly. Very cool.

absolutely crazy level of detail... in awe

Reminded me of a VRML demonstrator inside Notre Dame from decades ago. Different approach, similar outcome. (it used surface texture mapping inside a game engine from my memory)

A lot more architecture would benefit from being available like this splat model. The Pharonic tombs which you can visit in google/other virtual tourism are good, but this is also good!

Wow Did you have any apps in Apple Vision Pro?

The Keith Haring altarpiece is a really cool surprise!

It's unfortunate that this tour makes it very difficult to see. Really not a fan of this "on rails" presentation style. I understand the angles matter when viewing a splat, but come on.

The cars moving in the beginning is a nice touch.

Looks good the few seconds it works here. Then stops working and I have to close the tab and reopen for it to work again for another few seconds.

Firefox, Windows 11, Nvidia

Get the following in the console when it stops working:

  Uncaptured WebGPU error: Buffer binding 2 range 138024504 exceeds `max_*_buffer_binding_size` limit 134217728
  Uncaptured WebGPU error: Buffer binding 1 range 138024504 exceeds `max_*_buffer_binding_size` limit 134217728
  Uncaptured WebGPU error: In a set_bind_group command, caused by: BindGroup with '' label is invalid

I like the moving cars. They're copies of the stopped ones right? Adds a good effect.

This is such a cool immersive experience on mobile that works so well. Great job on this!

Wow, I didn't expect to see transsexual steps in front of a church.

Did you animate the cars separately? That really did a lot to add to the immersion (and the sound effects too). If nothing moved I think the effect would be significantly diminished.

Unreal. It’s been years since I’ve been here. It’s crazy the fidelity you can capture. Stunning work.

Unrelated silly question. Are you the same Vincent Woo who went over the whole unit combination story on Medium of a supervisor?

Gsplat is indeed the future for graphics. Handling much more detail in mobile hardware spec. Check this work too. (Not mine) https://demo.immersivetech.ch/chateau-la-sarraz/

The Peek mode is insanely good, it reminds me of those exploded views of buildings and "how things work" children books.

The model seems to be having a hard time with the marble floor in the quire (low resolution), is this because of its reflection?

Wow that's crazy that they built an apartment building where it would shadow all that stained glass.

I bet there's a story there.

Woaah, zooming all the way out is really cool

The cathedral is the star of the show, but I found myself more fascinated by all the incidental little details captured in this. Like the trees and the buildings nearby, the basketball court, the little solar panel on the side, the apartment towers.

It's like seeing the promise of Google Street View realized.

The technology is in such an early stage and it already slaps this hard.

Wonder what the next steps are for this tech? "Un-splatting" optimizations to convert things like flat surfaces into classic rigid textured geometry? Factoring the lighting away from the geometry? Filling the pipeline with AI tooling - segmentation to remove the "variables" like humans automatically, generative AI to fill in the missing non-semantic details based on the surroundings, more generative AI to "port" the data from things like public high resolution images of plaques or other undercaptured details into the scene?

Seeing this kind of reconstruction now makes me very excited for what the 3D environments of the future are going to be like.

what kind of drones did you use for this.

That's really cool

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I'm not sure why, but my brain always gives a strong "this is not real" alert with Gaussian splats. Something about the lighting is really off for me.

And whenever I see videos explaining the Gaussian splats, they always claim they are supposed to fix lighting issues.

Is this a function of "not enough detail" or.. Something else?

Combining the interior and exterior captures sounds like the hard part. How did you get the two sets registered to each other?