This brings a meta quest 3s to its knees. It's almost so bad you can't quit it, and the video lags 15 seconds, which is very disorienting to be immersed in (it can make you fall down). Shame, since it looks gorgeous.
The Quest's Snapdragon GPU, like most mobile GPUs, uses a tiled rendering [1] architecture.
The basic technique for rendering gaussian splats is kryptonite for this architecture, essentially implementing every worse practice for rendering on a mobile GPU:
* Tons of overdraw (overlapping splats)
* Tons of alpha blending
* Millions of splats in the distance generate a lot of tiny triangles resolving to a single pixel
* Long thin splats in the foreground generate triangles that cover multiple tiles
These are all the ingredients you need to bring a mobile GPU to its knees! Any desktop GPU (including most laptops) will be far less sensitive to these issues, even if it's not very powerful. It's a fundamental issue of architecture rather than one of raw FLOPs.
The quest is underpowered (it's basically a midrange Android phone you wear.) More efficient coding or a simpler model would help. Inside the Scaniverse does something similar with a high framerate but the models are simple and don't look very good.
I had to power cycle mine to get out, but boy was the view great despite the motion sickness.
