Dark slots on mesh, after light building

So, I create in 3ds max a scene with 65 objects, a 3d render of exterior and interior of new house for my client.

I created 80% of scene allone, just few items I download from CGTrader, and transform to quads.

Why? Because my client want 3d walking inside house, so I decide to use UE4.

I made cca 15 render images in 3ds max with mental ray, and everything is great.

I imported all my scene to engine, adjust lighting, add lightning etc, and after light building I have some problems with some objects. Ok, for some object i know what is problem (bad UV, or bad triangulation), but I have 2 problems that I dont know how to fix:

1.) I created hous wall from 2 objects, and now in UE4 I see on my wall where house is connected, why? Both sides of wall have same material, in 3ds I dont see this problem.

2.) On white pillow, I see black spots. Why? I checked normals, UV’s, I tried too many ways to work again on normals and UV’s, I tried to increase lightmap resolution, everything, but I dont know how to fix problem.

First issue is that UE4 can’t match lighting between separate objects. So for a flat wall, don’t make it out of multiple objects, make it one object.

Second issue–looks like your lightmap UV’s are overlapping for the pillow.

Uhhhh ****, but now it is to riski to make that wall from one object, is there any way to fix this, maybe to play with normals?

Second issue - there is no overlapping Uv’s, but UV’s was very bad, so I create new pillow and work again on UV’s and now is great :smiley:

You can’t fix the lighting issue–separate objects are processed on different threads, which means there will be slight variations between them. The only way to avoid it completely is to make the surface a single object. You can improve the results but it won’t go away entirely: