There are certainly efforts (see: Google Stadia) but so far these are big commercial projects. Most commodity servers don’t have GPUs at all, so I expect you would need specialized and rather expensive server hardware to do better in realtime than WebGL in a browser.
The two projects that I mentioned in my original post perform this “rendering” in the browser. What prevents us sending this scene to a “nodejs” based server ?. Any work in that direction ?
Sure, there’s no reason you can’t do that, using something like headless-gl to replace WebGL. I wouldn’t expect to stream raytraced scenes in realtime to many clients with that, but it should work for individual renders. Some polyfills and patches may be necessary since three.js is mostly designed to run in a web browser.