Material wrong rendering on mesh

Hello guys , earlier today i imported an obj of a building in ue4 editor , but when i try to apply materials on it , materials does not seem to render right . Materials appear like they have a single color. I built the lighting and played around with material settings on the mesh setting but nothing seems to work .How could i solve this?

Do you have overlapping UVs on the model?

Or better yet, have you unwrapped the model? if they are single color, that probably means you will need to go back to blender, apply uv-maps to it.

No , i got no errors in the light build.

Thanks for your help , its probably this, but my object is made from many little objects, do you know how to uv unwrap it or any good tutorial on this? All tutorials show how to uv wrap a single object.