Leungchunghong

My Bad, did not know know have such "Pony Wall" option... haha. Thanks Lot.

Looks ok. No light through the wall corner. The slightly orange is the light from the back. thanks lots.

Doing "a short L shape" lower half height wall and upper half glass panel to the area highlighted in yellow. It seems too short to add in a windows to the shorter side of the wall.

I created a roof but the light still went through. The wall material in use is "Default: Plasterboard" . I tried adding Polyline solid to whole wall. 10mm, still goes through until 50mm., but the wall overall thickness increased significantly. So I changed the material to "Grey Shade", yes it blocked the light. I believe the material does matter. Thanks Both.

I have this light reflected from outside's rope light... The wall should not let any light from outside shine through. Even with render, similar issue. How can i fix it?

You are correct. Thanks.

Why do i have the red/blue arrow and how do i disable it in the camera prespective? (Render Technique is "Physically Based")

I found it. The windows is not maximized and it is hidden behind the taskbar.

When performing ray tracing, there is a status bar at the bottom of the screen to show the progression of rendering. Suddenly, it went missing and never comes back. I also went to edit - preference - appearance and ticked every option it has, but still not appearing.