You don't have to go as far as proper raytracing. After all, Chessmaster 3000 I played with in the 90's was already able to offer a decent "3D" board look, certainly better than what Lichess has now. I'm pretty sure with technologies like WebGL it would be much easier to achieve today. However, as with most features, the problem is finding someone who would be both able to implement it and willing to spend time doing it.
You don't have to go as far as proper raytracing. After all, Chessmaster 3000 I played with in the 90's was already able to offer a decent "3D" board look, certainly better than what Lichess has now. I'm pretty sure with technologies like WebGL it would be much easier to achieve today. However, as with most features, the problem is finding someone who would be both able to implement it and willing to spend time doing it.
