Placing a rect light in between two static meshes causes the surface to be extremely bright. This will happen even though the lights settings are default. It will not happen if it is lighting just a single surface.

Found in 4.20 Preview 1 CL# 4112139 and 4.21 CL# 4115885

Steps to Reproduce
  1. Open the editor
  2. Make a new blank level
  3. Place two planes in the level and set their X and Y scale to 4
  4. Place them so that their surfaces are facing each other but spread apart
  5. Place a rect light between them so it lights both surfaces
  6. Build lighting

Alternatively you can use the project attached using the steps below

  1. Open attached project
  2. Build Lighting

The surfaces being lit by the Rect Light will be incredibly bright even though the settings of the light are default


The surfaces will be evenly lit

Have Comments or More Details?

There's no existing public thread on this issue, so head over to AnswerHub just mention UE-60104 in the post.

Login to Vote

Affects Versions4.204.21
Target Fix4.21
Fix Commit4084945
Main Commit4470579
CreatedJun 7, 2018
ResolvedOct 8, 2018
UpdatedOct 15, 2018