Why do UMG Widgets Flicker on iOS/Why are pictures blurry on iOS?

Development Programming & Scripting UI
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21

It should also be noted that I have more than 1 UMG widget in that repro project but only one of them doesn’t draw correctly.

22

Hello kgamble,

Thank you for providing a project to take a look at. However, can you reproduce this issue in a clean project? If so, could you provide a detailed list of steps on how to reproduce this issue on our end? As for the flickering that I saw in the provided project. This was due to changing the visibility on tick.

23

Yes, I did repro this in a clean project. The steps I took were the following:

  1. Create a material, set its domain to UserInterface, set “Final Color” to a constant vector 3 of (0, 0, 0).
  2. Create a blueprint inherited from HUD. Add “Event Receive DrawHUD” to the event graph, create a “Draw Material Simple” node that draws the material at (0, 0) with a size of (32, 32).
  3. Create a UMG widget. Add an Image to the Canvas Panel, put it in the center, set its brush to the material.
  4. Create a blueprint inherited from GameMode. Set its HUD class to the blueprint from step 2.
  5. Go to the level blueprint, in BeginPlay add a create widget node with the widget from step 3, add it to the viewport.
  6. Save the map, set the project’s default map and game mode to the map and game mode I created.
  7. Run in PIE, see a black square in top left corner and the center of screen.
  8. Run Standalone, only see a black square in the top left.
  9. Break link to “Draw Material Simple” node in the HUD blueprint, run Standalone and see the black square in the middle again.

I’ve also attached my new project since it doesn’t contain any assets from my current project unlike the last one I sent you. Thanks.

24

We managed to get rid of the flickering by turning off metal under IOS settings.

25

Hello kgamble,

After taking a look at the steps provided I was able to reproduce this issue on our end. I have written up a report ( UE-31791) and I have submitted it to the developers for further consideration. I will provide updates with any pertinent information as it becomes available. Thank you for your time and information.

Make it a great day

26

Just to add, I’ve experienced this issue on two separate projects and only on the iPhone 6. So it is indeed a big issue. As mentioned above, turning off Metal fixes it.

I searched that issue on issues.unrealengine.com and could not find it. Is it still under consideration?

27

Hello Jason.Pecho,

I have pushed this issue to the public tracker. It appears that this was closed as by design. I hope that this information helps.

Link: Unreal Engine Issues and Bug Tracker (UE-31791)

Make it a great day