Unreal 4 Lightmapping Issue

JakeGuestArt

Hi All,

I hope this is the right place to ask this, cause I've been looking for a solution for days and can't find anything that relates to what's actually going on and I'm close to pulling my hair out over this.

Long story short, I'm creating a scene and getting lightmap UV errors. I was using generate lightmap UV's in Unreal and that didn't fix issues. I created my own lightmap UVs in Maya and that fixed the issue for a few of the objects, but some objects just will not change no matter what I try. I'm currently working to fix a tree that just will not change from the 97.4% overlap issue and the Error Colouring in UE4 isn't helping as the issues don't match the lightmap unwrap at all. I've reduced the lightmap down so the shells are absolutely tiny and have 8+ tile space between them, but I still get the error. I've Re unwrapped the tree and it hasn't fixed anything.

Am I overlooking something basic? Or is there just something wrong that I didn't know existed. 

Any and all help would be really appreciated!


Below - Setting in UE4 with lightmap set to UV channel 1 with a pack resolution of 256



Below - UE4 Overlap error (Tree is PineTreeVar1)


Below - Repack for 32 resolution but still receiving overlap error


Below - 64 Resolution pack with 97.4 error


Below - 256 res pack with same error

Obscura

What is the "lightmap coordinate index" set to, in the static mesh? 

JakeGuestArt

Obscura said:

What is the "lightmap coordinate index" set to, in the static mesh? 

Honestly, I had no idea that setting even existed. I thought the source lightmap index was the option used to set the UV channel for lightmaps, but I was obviously wrong. I know it may not seem like your suggestion could have solved much, but I've been searching for a solution to this on and off for almost a year, and avoided Unreal as often as I could.

Thanks so much for replying, and thanks so much for solving this for me (':

Obscura

Great. The source lightmap index is used to tell which uv channel to use when Unreal auto generates the lightmap uvs for you, from an existing channel. The destination index is used to tell it where to put that auto generated lightmap uv.