Please help with some lighting/materials question.

Hi,

I am just starting with UE and I ask please someone to help me with some questions ?

About multiple materials :

I was adding multiple materials on a building by selecting polygons in maya and then applying the materials. Then UE would import them and it worked fine.
But what if I want for example … imagine I have a room and in 4 walls I want a different material. Could I just split the 4 walls into 4 individual pieces
and then apply the materials in UE just by clicking on them? Does it cause any issues ? Consider that the 4 walls are still in same place closing the room and the
vertices although disconnected, they are still in same position as if they were together.

**About static light **

I have this huge building with a big window with a hall and sun outside, and inside the hall doors that lead to small rooms without windows.
When generating the lightmaps, the big hall gets entirely lit, but the small rooms black.

Does it mean that static lightmap does not catch any global illumination?

If I generate the light using stationary, then all rooms get lit.