UE4 LightMaps how important?

David1983

Hey Guys…
I have a general question about light maps in UE4.. I would simply know how important they are? Is there a need to make them really proper? I mean when the space between the UV Islands is to low etc… they cause lighting problems but is there a need to stich some of the UV islands together for better results etc ? I mean it is a totally nerving work which wasn't necessary in the cry engine….

Just forgot one thing, is a light map resolution of 512 or 1024 ok for a big building in UE4 ?

snoop

All you have to do to generate lightmap UVs in a program like 3ds max is to use flatten mapping in the uv editor. In the options before generating the flatten mapping, just up the uv spacing. Then you don't have to worry about bleeding issues. If you aren't using 3ds max, I'm sure other programs have an equivalent to flatten mapping.

David1983

Ok, i'm just asking cause i saw a tutorial where the guy stitched some of the UVs together for better results..

I created them the way you wrote, simply in the second UV Channel by flatten mapping etc…

What about the light map resolution in UE4 i set it for big buildings to 512 or 1024 its that ok or to much? reducing the light map resolution results some lighting issues...

ZacD

Where ever there is a seam on the lightmap UVs, it's possible there will be a seam in the lighting. Typically stretching is a lot smaller issue than having more seams, that's why people stitch together as much as possible.

1024 is fine for an entire building, the Unreal Engine will automatically switch between higher and lower resolution versions of the same lightmap to save memory.

David1983

perfect thanx!