Reflection Capture Problem

What am I missing here?
Thanks for any help!

also… planar reflection is to expensive and didn’t work. Frames are dropping below 20FPS… cause of the huge mirrors… I really wonder how you tackle a scene like that?

Reflection captures aren’t going to show your character/dynamic objects and they all need to placed/scaled appropriately to not create any extreme distortions in the projection. SSR will only reflect what is on the screen(excluding back faces). The two are usually combined to get the best of both, but are obviously poor in some areas.

Planar Reflections would be your best option here, but you’ll likely need to make some changes to it. You can disable capturing every frame and a few specific rendering features to reduce the cost.

These reasons are why most, if not all, games even to this day don’t have mirror walls. :slight_smile:

@BernhardRieder - The "Lighting Essential Concepts and Effects" course on:

https://learn.unrealengine.com/

… particularly the section of the class titled “Lighting Essentials: Reflections” helped me understand this quite a bit … like why your geometry is getting clipped in SSR. I agree with @rosegoldslugs that Planar Reflections are probably your best bet. You could also try experimenting with “Scene Capture Cube” … it’s explained in that same Reflections lesson I mentioned. Good luck!

As far as i have understood, those screen space reflections can only reflect, what your camera (or the reflection plane) can see, the rest is guess work and interpolation at best. And since your camera can only see the back of your char it cannot mirror its front in your mirror wall.
So as BrianAllenHill had mentioned, without raytracing, your best bet would probably be SceneCapture as mirror, and making the mirror wall a big video screen, that plays whatever the SceneCapture captures.

the problem is… that even using a planar reflection… the mirror itself is not just flat and planar. The mirror has additional forms, and shapes. like little bumps inside every section.
I also tried the SceneCapture. But the problem that you’ll run into … is the fact. that the SceneCapture is just a projection… and therefore… in runtime… the reflection is not dynamic.
Uff… I am assuming… a space with huge mirror walls… it’s just not doable at all in runtime… or am I wrong here?

The SceneCapture should be dynamic, basically capturing a live video of what it sees and then streams it as a video to your mirror. Maybe this video helps you a little bit, it´s a comparsion for 4 mirror versions, including Planar and Scene Capture as the last version.

like I already told you before. Your best bet is to use a custom scene capture, and target ONLY movable objects.
This costs much less then capturing the whole scene.

You then use the render texture within the mirror material so that the material displays a live image at runtime.

You can have all the bumps and shapes you want.
you just need to make sure that your render target is properly distorted to match.

and, for performance you still want to leverage the reflection capture.
it is static, so it will not render objects set to movable by nature.
the material will blend it automatically with the reflection. You just mask the area where the movable objects are to be more rough so you can fake the reflection.
Maybe for a better effect you also add a transparent plane on top of it with even more detail so its like a real mirror.