Lightmap errors on project migration from 4.11.2 to 4.12.3/4.12.4

96636-lightmass_4_11_2.jpg

Correct Lightmap in 4.11.2

96637-lightmass_4_12.jpg

Lightmap of converted project to 4.12.3/4

This problem covers almost all meshes in the level.

Rebuilding lightmaps doesn’t solve the problem.

Moving far away from level some times fixes the issue on some mesh but pretty randomly look like is some kind of lodding but no LODs are present in the geometries.

The issue came back on each map or project reload.

Packing the project doesn’t solve the issue.

Hi rgemelli,

Thank you for submitting a bug. Unfortunately I had trouble reproducing your issue in 4.12, here are the steps I took:

  1. Opened a blank project in 4.11 with parameters set to Desktop, Max Quality, and No Starter Content.
  2. Deleted the Skyphere and Atmospheric Fog from level.
  3. Added a basic sphere static mesh from the basic tab on top of the floor so that it rests in the middle and intersects. (see screenshot for reference.)
  4. Changed the Directional Light in the scene (Light source) to a static light.
  5. Built the lighting only on preview lighting quality.
  6. Saved all and named the map “test Map”
  7. Opened the project with 4.12 and selected the “Make copy” option.
  8. Opened Test Map

Can you reproduce your issue in a blank project on your side? If you could provide any additional information that you think can help it would be greatly appreciated!

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