Floor is black after light building

Dear friends,
am facing strange problem here as am using brush box for the floor and i applied a material to it but after light building it turned to be black. any idea whats happening here and how to solve it?


by the way I checked if there is overlapping but not there is not

Do you have a skylight and reflection capture actors in the scene? A material with such low roughness doesn’t really get any diffuse lighting, only specular and reflections from the reflection environment.

Yes I have skylight and reflection sphere in the scene and after changing the roughness value from 0.1 to 0.4 am still getting the same black color

Messed up normal map? Try unplugging it.

just tried it now but still same issue :frowning:

I dont think the problem is related to the materials it self as i tried and changed the material of the floor to another one from the scene which have no problem and again it turned black

I made new copy of the floor with the same material and I moved it out of the room then i rebuilt the light and the out floor looks perfect but the one inside the room have the same issue
any idea whats happening here???

Does the floor have a proper UV map for the lightmap?

its a brush box . from what i know it should have it by default

Ok finally i figured out whats the problem is :smiley: the problem was the Normal map but why dont ask me :stuck_out_tongue:

My friends after rebuilt I had the same problem again but this time I found how to fix it.
after the last update for unreal 4.5 the unreal started by default to generate UV light map what is causing all this issue (which is very helpful if you have an object without UV channel for light building) but in my case I have my own so I had to go to the static mesh details panel and un check generate UV and thats it :smiley: all done now without any problem