Backward Reflections

[Vernatia_1 (RyanJames)]

I’m having some problems with reflections.

If I have a light, in front of an object, with another object behind it, I get a reflection of the first object where shadow should be on the second, both objects use the standard M_Metal_Chrome textures to make the reflection clear:

I’ve included text and a plank to make it more obvious.
As far as I can tell, it is reflecting what the camera can see (the reflection is cut off if the camera cannot see the reflected object, but can see the reflection):

It is possible I’ve changed a setting somewhere that has affected this, but it is a very odd thing to be able to toggle.
The light is just a standard point light, as is the text.
Both the plank and arches are static meshes.

Any help would be greatly appreciated.

[Lovecraft_K]

Hey Vernatia -

Have you added a Sphere Reflection Capture Actor to your scene? These will greatly change the look of your reflections in the map.

Let me know, Thank You

Eric Ketchum

[Vernatia_1 (RyanJames)]

Thanks for the reply Eric.

I’ve actually tried both the Box and Sphere Reflection Captures, but they make no difference.
Honestly, I’ve never seen a difference when adding a reflection capture actor to the scene, it is possible, somehow, we’ve broken it, though not sure how.

Basically, the sphere capture makes little difference to the reflections:

But one thing I did note, hence why I said “little” not “no” was, if the sphere capture was moved, it make a small difference in the brightness of the shadows on either side of the arch:

I’ve also had a test to see if it was the static meshes that were causing it, so I put a Box in the way, and gave it the same material, and it still shows the reflection.

Basically, it’s like there is a reflection sphere around the camera that is overriding all reflections in the scene, but I can’t for the life of me work out what or where such an thing exists.
It doesn’t matter if it is in the editor or in play.

Actually, I just started up the FPS example, and did the same thing, using:

• Wall_Door_400x300
• Wall_400x400
• M_Metal_Chrome
• Reflection Sphere
• Text Render

It still occurs, I have built lighting, told the Reflection Capture to “Update Captures”, and if I move the reflection capture around, it makes no difference to the text render and light splotch that is being reflected.
This is in v4.4.3, our project is based off the FPS example,but I wanted to test to see if it was a setting I had changed, but it appears not to be.

[Lovecraft_K]

Hey Vernatia -

Thank You for the additional information that helped me identify exactly what is going on here. The issue revolves around what the reflections from the sphere actors actual are. Essentially the sphere is generating a cubemap based on the position the actor is in so, this normally would not be an issue except when dealing with completely flat surfaces. This is discussed quite well in teh Reflections documentation found here, Reflections Captures in Unreal Engine | Unreal Engine Documentation

To solve your issue though a believe we can enable the Screen Space Reflections through a Global Post Process Volume. This should enable “true” reflections based on a distance calculations between player camera and the reflecting surface. At a distance though, the reflections will shift back to the cubemap based system, but it should be far enough away as to not be a major concern.

Thank You

Eric Ketchum

[Vernatia_1 (RyanJames)]

Thanks Eric,

That provides a resolution to the problem, thanks.
Added a touch of roughness to the model and the reflection vanished.

Regards,
Vernatia