Reflection problem, any help ?

[anonymous_user_d0ebbb201 (anonymous_user_d0ebbb20)]

Hi guys,

I have some trouble to understand how to manage the reflections in my scene.
I have an exterior scene with a 24 floors building who the main material are going to be something close to a mirror.

If I do nothing, the building reflect the sky sphere (BP_Sky_Sphere). Ok, that’s nice !
But i want to see the others buildings (neighbours, street, …) and at that moment, I don’t see that so I try with a SphereReflectionCapture placed at the ground inside the building.
Here is what I get : (little curvy reflection, stree light are twice bigger…)

Here I try with a wider radius and placed at the middle of the height of the building: (huge curvy reflections and the ground get an inception style)

So I decided to try with a BoxReflectionCapture, I have try with a wide radius (wide enough for the entire scene) at 50cm above the ground and inside the building. It was “ok” but I had some strange thing.

And lastly, I realized that the reflection appaers strangly when I was close to the building. Looks like a radius that beyond a certain distance becomes blurred.

And, I’m at that moment.
I don’t really understand how to setup my reflection.
For the test I’ve put a basic cube instead of the real building to setup that easily but I can’t do it properly.

So if you have any explainations or advices, I’m listening.
(I’ve already see the unreal doc but it’s mainly explain for interiors).

[rabellogp]

UE4 combines some techniques to generate reflections and none of them are perfect. By default you get Screen Space Reflections (SSR) which uses everything you’re seen on your screen to generate some reflections. The results are relatively precise but you wont get any reflection of things that are not appearing on your screen (say the buildings behind you). When you add Reflection Capturers (comes in sphere and cube flavors) you’ll get a baked 360 texture of the environment combined with SSR. The transition between SSR and reflection capture will never be perfect and won’t work at all for mirror-like surfaces. Then you have the Planar Reflections which may be the best option for you.

Take a look at this: Reflections | Unreal Engine Documentation
and this Planar Reflections | Unreal Engine Documentation

[anonymous_user_d0ebbb201 (anonymous_user_d0ebbb20)]

Thanks, that work’s !
It’s a little bit more ressource consumming but it works.

With the real model of the building is pretty good.
Thank you !

[heartlessphil]

You can raise the sphere reflection capture resolution since a recent update. The default resolution was 128x128 pixels but now you can set it to 1024x1024. It’s a huge improvement. Planar reflection is still your best solution for that particular building though.

[anonymous_user_d0ebbb201 (anonymous_user_d0ebbb20)]

Ok, good to know.
Thanks.