Random Flashes/Light Flickering

Hi everyone, I’m using Unreal Engine 5.4 with Lumen, and out of nowhere, I’m getting a random light flash in this corner, which is also appearing in the final renders with the Movie Render Queue (Image attached). Any idea how I can fix this? Thanks in advance!

Try in this way for Reducing Flicker in Movie Render Queue:

  1. Temporal Anti-Aliasing (TAA):
  • In Movie Render Queue, you can adjust the Anti-Aliasing Settings.
  • Set the Anti-Aliasing Method to Temporal Anti-Aliasing (TAA) for smoother results across frames.
  • Increase the Temporal Sample Count (e.g., 8, 16, or higher). This controls how many sub-samples are taken per frame, which can smooth out frame-to-frame variance and reduce flickering or light flashes.
  1. Motion Blur Settings:
  • If you’re using Motion Blur, ensure it’s properly configured. Flickering can sometimes occur if motion blur isn’t set correctly, especially in fast-moving scenes.
  • You can find this setting under Movie Render Queue > Motion Blur, and adjust Amount and Max Samples accordingly.
  1. Sub-frame Rendering:
  • In the Movie Render Queue, under the Settings for Anti-Aliasing, you can enable Override Anti-Aliasing, then increase the Spatial and Temporal Sample Count to get more precise results per frame. This forces Unreal to generate smoother results by rendering sub-frames between each actual frame.

By tweaking Temporal Sample Count and other settings, you can effectively simulate temporal accumulation during rendering, which helps Lumen behave more consistently in final renders.

Thanks for catching that, and I hope this clears things up!