Landscape flickers when distance from camera is large

I’m experiencing flickering artifacts on Landscape actor at far camera distances in UE4 4.14.

Artifacts happen even in a blank project with no settings changed.

Problem occurs in editor and standalone.

Problem seems to be limited to Landscape. It does not happen with static meshes at the same distances.

Problem happens mostly when the angle between the landscape surface and the camera is acute but will happen at other angles with increased distance.

It looks like a moire pattern / screen door effect from certain angles.

Steps to reproduce:

  1. Create a new blank project and a new blank level.
  2. Create Landscape with “Fill World” button. Ensure it is placed at origin (0, 0).
  3. Create material. Material is simple: Const Vector 3 (color) into base material input.
  4. Apply material to Landscape.
  5. Add Directional Light to level.
  6. Fly camera away (using speed 8) until landscape starts to flicker.

Note that this is an extremely simplified set of steps to create a level that demonstrate the problem.

Problem seems to be related to anti-aliasing.

Setting AA mode to FXAA or turning off Show->Anti-Aliasing seems to prevent artifacts except when moving the camera.

This problem happens with both World Composition and just flying the camera a certain distance from the landscape in a regular level.

Flickering starts to happen quite severely at distances around this position from origin / center of the landscape:
(X=-804017.125000,Y=139755.453125,Z=97068.093750)

You can copy and paste that line into any actor’s Transform → Location and then press ‘F’ with it selected to quickly jump there with the editor’s flying camera.

Update: When the Landscape is selected in the World Outliner hierarchy, the flickering stops completely, even when moving the camera. Enable Game Mode (G) with the landscape selected to get rid of the highlight. However, this is not a workaround or solution.

Here’s a screenshot of the issue:

Here’s a shot of the material graph.

Hello,

Maybe try, to set you engine settings to “epic”, to set your distance rendering to “epic”.
Maybe this could fix it.

Cheers, KR

Hi ,

I tried playing with those settings, but they were all already on Epic or Cinematic. Changing them doesn’t help, unfortunately.

Thanks for chiming in with a suggestion though.

Hey coreyx,

The flickering occurs at far distances due to reaching the extent of the landscape actor and its component’s bounding box. This bounds determines what does or does not get rendered based on the size of the object on the screen relative to the distance from the camera. I ran your test and can only see the flickering at glancing flat angles and very far distances.

This flickering is expected and can be avoided by increasing your landscape’s Positive and Negative ZBounds. You need to be careful when modifying this parameter, as it can reduce performance the larger your landscape and the greater the extension value.

Unless you have a very specific use case for needing to render your landscape in your project or game at far distances, I would advise against extending the bounds by too much. Sometimes increasing the bounds is necessary, like when using World Position Offset or Displacement. These routes push the vertices of your landscape in a vertical direction, therefore might push the landscape outside of its original bounds which will cause the same flickering you are reporting.

Let me know if you have additional questions.

Thanks,