Lightmapping artifacts

Questions & Answers
1

I’m trying to render a lightmap for an interior scene.
While most of my scene is lit ok, I’m having a major issue with the ceiling.
The architecture of the interior is basically a ceiling covered with a web like construction of planks, that should create shadows on the ceiling.
The scene is illuminated with area lights on the floor.
The problem is that for some reason, the ceiling gets mapped in a VERY low resolution, or so it seems, and the lightmap comes out as the attached image.

Does anybody know why?
[888-Schermata+05-2456059+alle+11.04.47.png|888]

2

It’s not a solution but I’ve found that the reason was light emitted by area lights and light emitting materials have caused bad light calculation.
Fixed it using only point lights for light-mapping calculations.