I was building a tunnel since I got my farming fields on the other side of a hill where the other players settled down.
So I decided to build my house inside the tunnel. Everything was all right until I looked at the ceiling of the house and it was like the game was trying to show me the sky, because the view was like when you fell from a world hole.
I uploaded it to youtube: https://youtu.be/0o_wPPS85xM
This only happened once I finished the building. Before that, the ceiling was normal like the one shown outside the house.
Also, I may be using it wrong, but my door was at the middle of the entrance, hehe, and it's difficult to pass it trough. I don't know if it's a bug or if I don't know how to use it xD
ahh.. know what this is =P file a bug report for it =)
Ah yeah this is a fun side effect of our block building code - we'll be resolving it with the art pass likely.