Staircase tower

Got inspired by a staircase tower or stair tower that you find in german castle also named Treppenturm, Stiegenturm or Wendelstein. It's a tower-like building that contains a stairwell, usually a helical one. After the modeling, I had some fun with the light point option.

In this variant, I let the light run upwards in the middle of the tower.

And in this the light follows the steps upwards. These shadow lines were created because of the bars.