How can I solve this rendering problem?

I tried to brighten these parts. But for some reason it didn’t get brighter. So I checked how does it look outside, and found out some weird looking sphere. It shows up whenever I try to render.
Could you tell me how can I solve this problem?

Are the faces of the window correctly oriented, with the white facing outwards?

1 Like

Thanks a lot. I never thought the faces of the window can cause this problem.

Thanks a lot. I never thought that can cause a problem. You saved my day :grinning:

1 Like

Many rendering apps use the convention that back sides point toward the interior of a solid 3D object where light can’t possibly reach. To reduce computation, they skip over these sides while rendering - without even examining whether they are actually 2D or reversed on the outside of a solid.