Black dots on baked lightmap (unity 5.4)

Hello !

I updated Unity to 5.4( 5.4.0f3) version and after that all the scenes force me to re-bake lights, because they were made in 5.3.5. And when i did that all my light maps bake with random black dots all over the place. I tried all the bake resolutions and different options - nothing changes. My model use no overlapping UV's, Generate Lightmap UV's flag is checked in import settings.




I found many forum threads with similar problems, but no useful tip were given in them.

Please, can someone help me with this issue.

PS. Problem appears only with area lights, with baked directional light source its OK.

 

Are the generate 2nd UVs selected on the mesh import settings?

 

thank everyone for replies. It seems that problem is in mesh indeed, because with other models bake works fine.

generate 2nd UVs always selected, but i think there is too much garbage in mesh vertices and triangles which ruin the bake. I will try to get a proper model and test light again.