Lightmaps

kapgowild

Hi guys, I've started studying lighting in UE4 recently, and I have a doubt about lightmaps. When we import an object into unreal, by default the engine generates the lightmap uvs for us, so I was wondering, when would I want to manually create lightmaps in a 3d package? Can those auto generate lightmaps be a bad thing sometimes? thanks

poopipe

99 times out of 100 you want to let unreal do it. 

If it produces artefacts on something important enough to warrant the work then you'll want to do them manually

sprunghunt

poopipe said:

99 times out of 100 you want to let unreal do it. 

If it produces artefacts on something important enough to warrant the work then you'll want to do them manually

This is highly dependent on how you have unwrapped your base model. 

One situation that I would not use auto lightmap generation is when you have shells with overlapping uv's. Unreal's auto lightmap generation only does an auto-layout on the shells from the source channel. If you have shells which are overlapping it won't unfold them for you and you'll get bad lightmap UVs.