Lightmap UVs are overlapping by 15.8% Error

kimchee519

Hi all, So I keep getting this error message in UE4 about my lightmap for a particular mesh that says "Lightmap UVs are overlapping by 15.8%" When my lightmap is not overlapping at all. I have 2 channels for the light map, 0 for the main and 1 for the light map, and there is not overlapping and plenty of space between the islands. Any idea whats going on here? I'm currently using version 4.4 of UE4. Thanks for any help on the topic!

MeshMagnet

Maybe show a pic?
Also, the newer versions will do the lightmapping UV layout for you.

kimchee519

Really? So there is not need anymore to lay out your own unique lightmap UV's for UE4? Strange, I always thought that you had to do your own. I've tried the UE4 lightmap layout for the 2nd channel but it does not always come out correctly..

divi

the newer versions will take your channel1 UV layout and pack that with lightmapping in mind. it doesn't necessarily produce great results on all assets, but can on most.
your problem is most likely due to the lightmap coordinate index being set to 0 instead of 1 in your mesh settings. might have to expand the details to get to that.

FW911TTW

For my OBJ imports, UE4 would automatically map my assets. This ended in some less then pleasant results when I baked lights. However, FBXs will carry over your lightmaps. Are you stacking UVs someplace?

Ssjtroll

Check on your uasset that it is reading uv channel 1 for lightmaps, sometimes it will switch to channel 0.

stefmen

Did you turned of "create lightmap uv's" on the import of your model? otherwice UE4 wil create it's own and they are really messy and have overlap