Hi All,
I am importing FBX model into UE4 (exported directly from sketchup).
After Building lights, i will get error with overlaping textures.
I have already seen solutions for this but I thing they were written for older version of UE4 as long in Mesh Viewer I have no option to turn on “Generate UVs”.(I am using 4.5.1 UE4)
My Lightmap index is set to 1.
Please see image below as an example of bad shadows populated after building light.
Thanks,
Michal
Have you tried setting the material to unlit? Overlapping textures sounds like a UV issue though.
Hi Michal,
With the release of 4.5 there were some changes to generating lightmaps. Now when you import a mesh it there is an option that labeled “Generate Lightmap UVs.” This is checked by the default.
So, in theory, you should already have lightmaps that are generated, but there is one caveat to generated LMs. They generate based off the texture UV (UV Channel 0 in UE4) and it will not break edges so this can lead to overlapping UVs even using the generated method.
First let’s check to make sure the UVs are there.
Open the mesh in the Mesh Editor and in the tool bar click the button labeled UV. Then in the drop-down bar to the right select UV channel 1 (This is the your LM). If there is not a UV channel 1 we can generate one.
In the details panel on the right under LOD0 you’ll see the drop down for Build Settings. Select a LM resolution and click apply. If you have a larger mesh then using a larger power of two value will work (128, 256, 512).
If you’re LM has already been generated the only other option to fix LM UV overlapping issues is to use an external program that can edit UVs or modeling software that has UV editing support.
A good tool that many developers use is Headus UV Layout. You can try it free from their website and see if this is something that would work.
Tim
