Chrome material dark after building


I’m using the built-in M_Metal_Chrome used in StarterContent (with Roughness adjusted to 0.15 instead of 0.25, metallic set to 1) on custom meshes in my interior scene.
When putting the mesh in the scene from CB or modifying it, the mesh looks good.
After building the light, the mesh looks much darker, and I can’t find why the hell.

I’ve got some box/sphere reflection capture objects in the scene, lights, skylight, LightmassImportanceVolume, lighting quality set to production…

See attached :

The selected object has been moved to show the difference between calculated lighting (the credence bar and skimmer). All 3 have the same M_Metal_Chrome material applied. Just over them is a spotlight with ies profile.
I guess the final render should be like the selected mesh shows it…

Any idea about how to correct this ?
Thanks a lot.

They should look as expected as long as they are inside the reflection captures. Otherwise it may be that their lightmaps aren’t good or lightmap resolutions too low and so the shadows are bleeding all over the mesh and affecting the reflections.

Yes that’s what I guessed too… but all lightmaps are overriden to 128 minimum, and the objects are inside the reflection captures (3 in this kitchen).
I just checked their UVs that are correct.

Really, I don’t find where the problem could come from :confused:
Any help would be appreciated !

Okay, some other objects I have in my scene show the same problem since I added new ones.
After disabling all the sphere and box reflection objects, it seems that the problem comes from these reflection captures.

I’ve looked around and found in the UE docs that it is commonly used to set one big sphere reflection object in the scene, then add smaller ones in strategic zones of the scene.
However using this method lets my metallic objects look darker even if I had only one reflection capture object.

Could this come from ouside objects I have in my scene (Trees, fence…) ?

And after some tests, disabling ALL the reflection objects in my scene lets the metallic objects show the same dark reflections…

I gave some time to show you better my scene setup :

  • dotted rectangles : box reflection objects
  • dotted circles : scphere reflection objects
  • yellow arrow : sun direction (light source)
  • light blue rectangles : windows
  • green marks show where the reflections seem to be correct
  • red marks show the reflection bugs (previous screenshot was taken in the down right corner, as the kitchen)

Is this setup correct and/or viable ? Is there a better way to go with the reflections ?
I’ve to admit i’m lost, I’ve tried many layouts, with all sphere captures, all cube, none… The reflections looked good some days ago, and started going wrong since I’ve added some decoration elements in the scene (cook ware, artworks, plants…).

Thanks a lot !

Hey Teapot Creation,

Do me a favor and use the ‘Recapture’ option on your ‘Skylight’ actor to see if that has any effect. Do this and then rebuild your entire scene using ‘Production’ quality lighting.

Also, uncheck the ‘Lower Hemisphere is Black’ option on your ‘Skylight’ actor.

Let me know if these suggestions helped, or if you need further assistance.


Hi Andrew,
Thanks for your suggestions, however nothing changed after recapturing the scene through the skylight.
Also unchecking the mentioned option made the scene lightly brighter, but nothing significant.
The skylight object is set to stationary, should I change that ?

Setting your ‘Skylight’ will give you the highest quality and highest mutability.

I would also look into adding sphere reflection captures instead of the box reflection captures. If you take a look at the documentation, which it seems you are following to an extent, we use sphere captures and light overlapping areas to get the best detail from the reflection environment.


Try the sphere reflection capture actors instead, and changing your ‘Skylight’ to movable to see if that improves your reflections.



I found this documentation page some days ago, and it was very helpful.
Also I tried using only sphere reflection objects : the results is significantly the same, only the reflection in a mirror in the bathroom looks like very stretched (for this object the box reflection seems to be the better option).
Also setting the skylight to movable makes a (too) big change in the scene, letting all the reflections to be very, very bright (and light blue), as if there was no sphere reflection in the scene. Should the movable skylight cast dynamic shadows ? All my objects are static (I looked for the best shadow quality and had some issues with dynamic ones).

Unless I have your project on my side, setting up reflections is just going to take some tinkering and experimentation with what works best for your scene. If all of your objects are static then you don’t need to case any static shadows. You will get good performance using static lighting, but the visual quality might not be as good as if you were using movable lights. Movable lights do incur a performance cost the more dynamic shadows it is being called to cast.

I’m sorry I can’t send you the whole project (16GB :/), but I’m trying all the different solutions I can think of… and none looks good.
All reflections looks darker than they should, especially on metallic materials (probably because they are easier to check).

Perhaps am I wrong about static shadows, I probably misunderstood some doc page. I’ll try with dynamic ones to see if it works better.

Thanks a lot, Andrew, I’ll come back to you after some tests.

Excuse me. I made a typo and need to correct what I said.

“If all of your objects are static, then you don’t need to cast any dynamic shadows”

Apologies, you were my first response this morning before my coffee :slight_smile:

What I suggest is try changing the ‘Light Color’ of your ‘Skylight’ to see if that helps brighten the reflections a bit. In other words, you said when you set it to movable it made all your reflections bright. Try keeping it at movable and darkening the light color a bit.

Hah, that’s what I’ve bet :slight_smile:
Trying with fully dynamical lights (and shadows) doesn’t work better at all, all is clearly too bright and “light blue” (the interior wall paint, whose should be white, looks light blue). However the reflections are better, in that point that chromium reflects the blue sky, and so appears bright…

Let’s try with your suggestion. Thanks again !

Thanks to Andrew, I’ve found some settings that look much better.
So my sun is set to stationnary while my skylight is set to dynamic, with a dark gray/blue colour. Also I had to delete many reflection spheres, those had as effect to reproduce in metallic object’s reflections an unexplainable darker capture of the scene. With only 1 or 2 reflection objects in each pieces the reflections looks good.

Thanks a lot again !