UE 5.1.1 Lumen lighting Popping when rendering with Sequencer

Hi All,

I have a scene where Im showcasing a product with a simple light setup - One directional, and a few rects for fill and rim. No sun/sky or anything like that. Its basically a high contrast render with a black environment. Im doing a camera orbit around the product. It looks great in the editor, and it also looks great with a sequence setup (I just ‘play’ the sequence, everyhting looks solid, no issues). Loving the Lumen GI bounces, all is good.

Then I add it to the MRQ, and render the project to frames, and here and only here, does this wierd light/shadow popping start happening. It appears to correspond the changes in the lumen scene info - when I have the image sequence loaded in a compositor, and I compare against the sequencer with Lumen Scene Visualization turned on, I can see the rendered popping occurs when the Lumen light maps are changing.

But I dont see this problem in the editor. And i dont see it just testing the animated camera orbit in the sequencer. I only see it when its actually rendered to frames.

This problem appears to be directly related to the sequencer. Though I have to admit, I dont know why the lumen maps are changing as the camera position changes… Ill be look at the side, and itll show one map for a while and then suddenly POP a different lumen lightmap appears (similair, but not the same, most apparent in the shadow areas).

So far ive tried:

  1. Ensured Distance fields is enabled for both the overall scene, and on each mesh of the product.
  2. Increased the max Lumen Mesh Cards from default 12 to 24.
  3. Enabled “Use Hardware Raytracing When Available” and also “Support for Hardware Raytracing”.

None of this has made a difference. And like I said, this problem only manifests when its rendered to frames. Everywhere else it looks great.

Is there a way to fix this?