Custom walls or ceilings can be used to create light troughs for reflected lighting, where light tubes or strips can be hidden in ceiling recesses, making the ceiling look aesthetically pleasing. The steps are as follows:

1. First, draw the area in the ceiling structure layer and set the drop height.

2. Click on the lowered area and directly click to create the light border on the area's properties bar to achieve the light trough effect;

3. Enter the profile editing section, and you can double-click to modify the width and height of the light trough.