Hey everyone,
I am probably what one would call a ‘Noob’ in the Unreal Engine and more generally in 3D.
I only have a few experiences with textures, so be indulgent with me 
Well, I’ve been looking for any kind of response about normal/artifact rendering in UE 4 and no one seems to solve my problem, let me explain :
Last week I wanted to start a personal project : creating, modeling and texturing an object for Unreal Engine in order to give me a sharper picture of how video games are made !
I started to design a weapon in ZBrush : I made the High Poly mesh and transposed it into a low poly version with 3DS max and applied the normal_map ( created with Zbrush) .
Here is my low poly with smooth-groups applied (I don’t know if it’s a good choice, as I said i’m experimenting and it was looking good for me for a first try)
I’ve learned how to create UV maps and decided to export my work in substance painter to finish the texture:
Here is a PBR render with substance painter :
The mesh seems to react correctly with the environment, no shader issue, the normal_map has been properly applied to it.
Here the low_mesh imported in UE without any material.
Has you can see, it’s still usable even if there are some little shadow issues with some sharp edges.
But compared to what’s coming next, it’s nothing
I’ve exported differents layers from Substance painter : normal_map, ambient occlusion, base color and mat_RoughnessMetallic.
I found a tutorial to apply those layers and unfortunately I have difficulties to apply the normal map to my mesh.
Some strange artifacts tend to appear and create strange shadows/ weird black areas over my mesh.
I first thought that it was due to “smooth group” in 3ds max and I made different attends but it’s not changing.
Then, I played with the UE material of the weapon, switching on and off the base_color texture, the ambient occlusion but it’s seems to come from the normal map.
I don’t really know how to imporve the final result , I used “NormalMap” for UE compression and texture Group is set on : World Normal Map.
Can someone help me to solve this problem ?
I tried to be the most accurate possible , I hope you’ll understand my problem.
Anyway, thank you to all of those who will take the time to answer me.
I hope my situation will help other people stuck with the same issue.
King regards.
NB: If you need more details, just tell me 
Thank you in advance for your answer.
