The steps above are reduced to their simplest expression.  I appears that several customers complained about lightmap baking resulting in glowing objects.  This typically happens on interior door frames and crown moldings around walls.

After digging some more, the problem is that in some cases, depending on how entities are modeled in max, Datasmith imports data in a way that tangents are scaled weirdly.

After lightmap baking, those objects seems to capture illumination from the sky - which is lot brighter than interior scenes, resulting in a "glowing" effect.


In SM Editor, you can `fix` it by recomputing the tangents .   Note that with FBX the problem doesn`t seem to occur


See this document.

more details:  [Link Removed]

Steps to Reproduce


Simple steps:

Export the attached scene

Look at the tangents in SM editor

SEE: they are in a "flat" incompatible form



[Image Removed] file:  [Link Removed]


Have Comments or More Details?

There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-70461 in the post.

Login to Vote

Fix Commit7649990
Main Commit9420574
Release Commit9552237
CreatedFeb 22, 2019
ResolvedJul 29, 2019
UpdatedOct 28, 2019