Lighting problems with imported CAD model



I’m currently studying technical design, and we are now working on 3ds Max 2020. I have an assignment where I need to import a .dwg model from AutoCAD, add textures and furniture, and lastly to light it with photometric lights and a sun positioner.

As a first attempt at lighting the model, I have placed a single photometric light in the first floor living room. However, it doesn’t provide any illumination at all, unless I set it to supernova levels (10 000 000 lumens), and reduce the global exposure value to 1. (With the sun up in the sky, I normally had this set to 15)

When I tried lighting a different model (part of a LinkedIn Learning course), I would get decent illumination with 2000 lumens, and the global exposure value set to 4.

Can anybody illuminate me (pun intended) as to why lighting behaves so differently in the imported .dwg model?

The project files can be downloaded from my Google Drive here:

The sun position has been set to 0300, so the sun is below the horizon. The only illumination in the living room should be from the single light in the middle of the room.
I’ve also included the original .dwg CAD drawing, in case there is a problem with my import into 3ds Max:

The instructions for the assignment state that we are supposed to use the ART rendering engine.

Any ideas are welcome, any working ideas are extremely welcome.

PS! Bear in mind that I only started learning 3ds Max 1,5 week ago, so I am a bit of a n00b.


have you check the size of the scene?