Hello there,
I’ve notices big Problemes while using the planar reflection componenten (not in the Viewport as Actor, but as Part of a Blueprint). It is not excaclty a Mem “Leak”, but it goes cracy at all. I think the problem is mentioned in UE-30669 but it is resolved as “won’t fix” !?
My Setup: Static Mesh Plane with a reflective Material attached. A Planar Reflection as a Child Component for taking the parents Location and Rotation.
As soon as you start “playing” around with the mesh - extremely on rotation - your RAM will go Crazy and your System - or at least the Engine - crashes.
I’ve testet this in 4.15 with a new blank project. In 4.14 I’ve noticed the component is not working at all (not the Actor - this works fine) which made me to upgrade my project to 4.15.
- Attached Screenshot you can see my RAM increase after roating the MESH only 10 Degrees. Watch at the Committed RAM and the 100% Usage of “Datenträger 1 D:” (Second HDD where my SwapFile is setup)
- The Secend Screenshot is after starting to play which seems to be the only way to clean up the RAM.
executing a “save all” seems to cleanup the ram also!
Hey Adnoh,
So I was able to reproduce the Out of Memory issue and decided to go ahead and reopen the ticket you linked. There’s definitely a memory consumption issue here. You can see the updated report by following the link below. The issue went untouched for a while which flagged it for auto-expiration which is why it was closed as ‘Won’t Fix’
UE-30669
I did notice that when you compiled or saved the blueprint, the memory seems to free up a little bit. Now depending on how much RAM you have, you might hit the Out of Memory a lot sooner than myself (64GB RAM).
Cheers,
Hey Andrew, thank you for your response.
No, Compilation doesn’t help. But if you hit saveAll or start a PIE it frees up the memory.
The Problem occurs only in the Editor, when rotating the PlanarReflection in Game everything is fine (but I have heavy performance impact using the component at all! I need it for 2 CarMirrors, but it drops my FPS from 120 to 30 and each mirror requires around 6ms of GPU Time - I’m going for SceneCapture2d because it is useless in my case until getting fixed but the quality is not near of the great one I get out of PlanarReflection)
I’ve got 64GB in my notebook too, but it is not enought, even with the swap file 
the problem is not the RAM, it is eating up the VideoRam - so my GPUMemory of 6GB are gone if I rotate the planar a few times - then it starts eating up the System RAM to free up the GPU.
Well now the issue has been reopened, the memory consumption VRAM or RAM issues should get addressed in any case. I will say be careful with using SceneCapture2D within blueprints, as they also have a known issue with memory consumption when manipulating a blueprint actor that contains a SceneCapture2D component.
UE-43455
Cheers,
H
