Thanks Ryan, turning on bloom in light shafts activated the effect. But unfortunately it doesn’t have different colours, as you can see below:
Is there a way to make a shadow sharper? Or to blur these pixelated edges at least? Setting higher resolution for the floor is not helping much unfortunately:
On the other hand, it looks like this effect has it’s disadvantages (rays should stop on the balcony’s floor), but I guess it’s connected to optimization:
I’m also not sure if this is a bug - on the left and right are the same meshes, just rotated. Glass has a two sided material (I attach screenshot of it below). One side is always darker after building the light: