Slate Widget Flicker on iOS when using Metal


Our team have come across a pretty annoying rendering artifact that happens on iOS. We have pretty complex widgets with images, scroll boxes etc. from time to time (pretty often) many of the images and other widget elements will flicker for a frame display what seems to be a font and change zOrder.

See this image for reference, I was able to capture it on video and took a screenshot.

This only happens when we are using Metal forward rendering for iOS on iPhone 6, 6s and 7. Since the GLES2 will be deprecated in unreal 4.17 this is an issue for us.

Wrapping the images and other elements with invalidations panels help to reduce the amount of “flicker” but does not completely remove it.

Is there some kind of settings or something else to eliminate the problem?


Would be great if anyone from epic could clearly or have any insight in this problem.

Good Luck