Planar reflections only good for water?

Because the way it works right now, we can’t select which meshes it affects. It’s everything around the planar reflection actor or nothing. Am I right?

Here’s an example. I wanted planar reflections on my glass but not on the wood planks…it’s not possible right?


Correct; one of the listed shortcomings of the planar reflection actor is that “anything close to the reflection plane” will use the planar reflector for its reflections.
They seemed to indicate that some future version of the engine will let you mark which actors will use planar vs other reflections.
Meanwhile, make your planks a lot more rough and less metallic, and you’ll do okay :slight_smile:

Ok it was just a matter of tweaking the distance from plane fade start/end to match the windows thickness, pretty much. Not perfect but much better.


The roughness value does nothing when planar reflection affect a mesh it’s full mirror or nothing!

I’ve gotten good results with glass and mirrors by using a cube reflection capture actor directly in front of a mirror or window, and now in 4.12 you can up the resolution of reflection probes.

I’mma try this out ZacD, because planar reflection is still very ressource-heavy. This scene ran at 80 fps on my gtx 980 and iI get sub 30 fps with the planar reflection :-S

Man, it’s work pretty darn well actually. Can you confirm the max res for cubemap is 1024? Imagine with 2048!!!

Yeah 1024 is max because higher resolution probes fill up your vram fast.

Much better solution for glass than planar reflections I think. Thanks for sharing.

4.13 has roughness based fade so that would fix this. You can also make planar actor very thin. For water I use 1cm fallof distance and it just work.

Can someone explain me why my sky light cubemap is getting reflected on my walls and glass (roughness 0 for testing) even tho I don’t have any reflection probes at all in the scene… It doesn’t make sense…
I use the cubemap with an hdri to light the scene, but I can’t get rid of it’s reflections… It seems to overrides any other form of reflections, like when I want to use a box probe like ZacD suggested.


I have quite a few mirrors in my game and was unable to opt into using Reflection Captures due to its MAJOR performance hit. Its sad to hear that Planar Reflections were a godsend that ended up being no different than the destructive predecessor. Just easier to use I guess. :confused: I’ll probably have to be tactful over its use and spend a lot of time optimizing my game. Oh well. Hopefully 4.13 will be worth it.

I don’t know if you know this, but the Skylight also generates a global Cubemap. Localized cubemaps will blend with the global cubemap for accurate scene lighting. This is why I opt to use very simple skylight cubemaps with a proper blend of colors and as little detail as possible. I normally use a lowres texture that has been blurred. Unless of course you need the global cubemap for crisp reflections.

Ok I see, thanks for explaining. Reflections as a whole is probably the thing I have the most difficulty with right now. When I use corona renderer and go back to ue4 I almost want to cry haha! Working so hard to do something that an offline renderer can do perfectly by itself is a bit depressing but heh, that’s how realtime works!

Anybody managed to get a good angular mirror with planar reflections? I mean, two separate mirrors that meet at 90°?

If you place a planer reflector on both mirrors, it doesn’t work?

Planar Reflections will not reflect within themselves in this instance. They will fall back to SSR and Reflection Captures for this.

Ok, I understand. Thank you anyway, it’s a good progress!