Strange problems in UE4!(i think are bugs)

hi guys,
how are you?
i have 3 Strange problem with UE4!
when i import a mesh in unreal engine,and create material for it mesh seem black in scene and i should to navigate camera and Approach it to can see model about normaly a bit.!(i think when i use from metalic!)

another problem is that u can see Strange material on mesh after building!(Spots and diffrent colors)

i deleted sample meshes in scene and you can see another type of bad materials in scene after bulding!

why i have these problems?
are bugs or i should to set things?
(for every model that i import to engine i see these problems!)

sorry,anyone is not?

Make sure that your meshes have a 2nd uv channel with a proper lightmap + add a lightmass importance volume + type in a higher value at lightmap res (e.g 128): That should solve your problem with the strange black spots on your mesh

Hey Mrdehnavi

I’m not sure I understand your problem correctly…

Just a few general notes:

  • Have you checked that the normals of your mesh are ok (no flipped normals)?
  • Are your UVs correctly laid out?
  • Could you open the material editor with your material selected and post a screenshot of what you’ve got there?

Do you get any errors when building the scene? These would help too…


thanks for your help!
but some points:
1-i did not use from uv unwrap and i textured my model as uv map modifire in 3ds max!
2-i did not set 2nd uv for lightmap!(because i have not uv unwrap and i use from uv map)
3-when i build mesh in scene i see this error:
4-when i set lightmap resulotion to 128 for example i see like this:
and for better i should to set on 4!

a quastion?
sometimes,when i build scene my scene be orange!!!my sky changed to Afternoon i think!why?

you can see shadows of models in scene!!!
direction of directionallight is from right of the pic.!
and you can see right models of this model in scene:

is not strange?
because i think should not shadows of this models be so far and long!

for every model that is imported in engine,should i create for it 2nd lightmap channal?(i didn’t it in udk for models that was imported!)

Hello Mr.Dehnavi

A few tips:

  • First of all, it is really important to get your UVs sorted out. I recommend that you go back to your 3D tool and have it create the UVs for you (a simple 3-plane unwrap or something similar should be fine for this test). UVs are a quite important part in the process and they can cause various issues when not done right (there’s tons of tutorials out there for tools like Maya or Max)

  • You don’t always need a second UV channel for the lightmap. But if the engine complains, you can create a second channel directly in the editor like this:

  1. Double-click your mesh in the content browser to get you into the mesh editor
  2. Go to “Window -> Generate Unique UVs”
  3. Select “Create New” and make sure that “UV channel to sve results to:” is showing “UV Channel 1”

  1. Click “Apply” (the rest of the settings should be ok)
  2. Now go to the “Light Map Coordinate Index” option in the details panel and set this to “1” (= Use UV Channel 1)

  1. Save and close the mesh editor
  2. Build

This shold take care of the lighting issues you’re having.

  • About the orange in the scene: Have you changed some settings of the skybox or the directional light?


thanks michael
my this problem solved.very thanks :wink:

this ways for solving my problem are orginal ways that everyone should to do these?or is a way to solve my problem?

i want to know why have i this problem?!

i found my problem for orange.(was from direction of directionallight)

new problem that i see is from all meshes!
see this pic:
you can see strange material in floor of chairs!
when i Approach to them it be good and has not problem!problem is when i am far from them!

see this:

this problem you can see in Columns of top!

with problem in sphere and floor of it!


“problems of unreal engine are very strange!!! in rendering!”

You’re welcome :slight_smile:

When you’re working in 3D and specifically with game engines, there are a few workflows that you need to establish, or you will run into problems sooner or later. Clean models and UV layouts are fundamental and need to be right. Take your time to do some tutorials on this - it’s worth it :wink:

Concerning your current problem: Have you bulilt lighting? Also, have you checked the lightmap resolution of these objects? If you get any errors, please also post those.


thanks :wink:

yes i built the scene.“build all”!

It is interesting that after any building i can see another shapes of materials of meshes on far seeing!

this scene was good and has not problem!i do not know!

my problems are very strange!
in starter map in new package created i see map that has not any problem!
when i build the scene again i see new problem in it:
why why why why???
and when i approach(near) it i can see good material:
this is not just in editor and these shots are from the game! :frowning:
why everytime i have new graphici problem in building?!

Just to make sure I understand this correctly: You only get these arfifacts when you are at a certain distance and not when you’re really close up to the objects?

see this steps of pics:

do you understand it?

may is this problem seem another…and like show just normal texture of it…! very strange!

Weird, I haven’t really seen that before. Do you have that just in this level or others as well (you can try some of the EPIC content demos)…

sometimes i have this,sometimes i have not this…
i this scene i have this problem…
in other sample scene i have this problem but just with black areas Instead Colorful problem!(this Colorful is not just seem!i can see sometimes for example just normal texture of mesh!!!(normal texture connected to diffuse!) or i can see a bad material of other mesh on another mesh!)
do you know what i say?
is very strange!
i think,i should to change my windows from 7 to 8.1!
my performance of system is good but i don’t know why i have these problems!?!

Could you post your PC specs?

  • Have you already reinstalled the UE4?
  • Start the UE4 with admin rights
  • Is this happening in every project or just in a special one?

I wouldn’t recommend switching to Win 8.1. Its far less stable than Win 7, especially for high-end work. We had a ton of issues in the studio with Win8.

At this time, I would look at your pc setup, as fighter mentioned. Could be a graphics driver issue or something related.

Can you post the graphics card you use, and the driver version?


thanks guys (IMX & fighter5347)
graphic card=>EVGA nvidia GTX 550 Ti
cpu=>AMD phenom™ II x4 965 processor 3.40 GHz
windows:7 x64

no i think i have in all scenes and projects!
yeah you say right!
my specs was as mentioned in up!
my driver version of graphics card i think is from 3 years ago about!i did not any graphics card update!is important?(new version is 335.23 in net)

Hi MrDehanvi

Yes, it is very important to keep your graphics drivers updated! You can miss a lot of functionality, apart from having quite some issues when you use drivers which are that old.

I would definitely update them to the latest versions for your card and check if your issues in UE go away.

It is generally advisable to keep your drivers updated…

Let me know how it goes once you’ve updated your graphics driver.


hi IMX and fighter5347

i updated my graphics cart and i do not see any problem in editor to now!

my problem is solved with updating graphics cart!

thanks very much IMX and fighter5347 :wink:

i did post this message to you know my result!


Good to hear! Enjoy UE 4 now then :wink: