Why Light Source Pass Through Floor?

Have a look the screenshot first.
The scene shown is the production quality lighting build + lightmass importance volume + 4 indirect lighting.
They said it must be something to the mesh Min lightmap resolution, but mine is 64. Isn’t enough? And lightmap resolution is 128.

It seems like the light pass through my room opaqueness and reflect on the wall.
I change apply all the settings above and rebuild the lighting on production quality rendering.

I’ve read some of the documentation, but it didn’t work well. Please help me with this lighting problem.


I think you should read more about lighting in Unreal!
First of all you don’t need those extra lights: you can get away with a skylight and a sun…
No, 64 lightmap resolution is not enough neither 128! …usually in an archviz scene a vase would have a higher one!
Think in pixels! Put a 64/128 res checker map on your mesh and you’ll see how low res it is… This(ish) what you give Unreal to visualize all your lighting information! :S Impossible!

No, I don’t think so. This is my first time experience this kind of problem. I know how lighting works, I’ve finished my course in game development with UE4. So, don’t assume me like I know nothing. What makes you think I asked this question before I read about it??

Ok, back to the question. Is that the reason? Well, I want to know the solution. As you can see on the plane of the roof(interior) it’s pretty dark almost like impossible to see. 128 is not enough? That’s weird and I’m sorry because I can’t accept that answer.
And btw, baking the light quality, really do help me out a lot but didn’t solve the problem. Preview lighting still leave the scene with weird black lines shadows. While Production quality baking lights, really improve the scene a lot. It takes longer rendering time, but it does the work.