I see font rendering is not adapted to 3D in the screenshot, so it is not yet ready for serious UI work. I presume curves are not rendered in an adapted way either, so everything will look pixelated around the edges.

Is it not possible to do serious UI work without fonts adapted to 3D?

I would say that the majority of people don't notice StereoKit uses regular raster for font rendering! However, that number is definitely not zero, and there's definitely people that can spot it right away, as evidenced. Designers in particular would probably spot it right away.

I'd say it's primarily a question of polish and feel! Those that can't spot it right away would still prefer SDF fonts in a side-by-side, and the difference becomes much more clear if you start getting your head really close to the text. I consider it to be an essential feature for a 1.0 version, but not a blocker for right now.

I actually worry more about looking at longer and smaller text in 3D. It is noticeably harder to read, which prevents many use cases. For instance, you would not read HN in VR using an RSS reader built with StereoKit.

Ah yeah I think there's a collection of issues related to small text within XR! The biggest one is really pixel density on XR headsets, which is always an issue for small text, or far-away text. XR also can't benefit from sub-pixel approaches to font rendering either. Since you can always move further from text, there's also the IRL issue that the text is just too far to make out!

The current raster technique should actually be fine for smaller text, there's some super-sampling going on in the shader that should help a bit here too! I'm not entirely certain what else could be improved on in this case besides font selection, I'd be open to suggestions or tips :)

Something like https://github.com/servo/pathfinder (newer) and as you mentioned SDF (older) are the latest approaches.