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UE4 Black leaves, uneven lighting when lightmap applied

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  • UE4 Black leaves, uneven lighting when lightmap applied

    I'm not sure what's going on here.

    Click image for larger version

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    I've tried the same tree in different test projects and it seems fine.
    There must be something else in this scene that might be causing the problem - maybe size of scene?
    I upped the lightmap resolution on the tree (River Birch Desktop) to 512 and see no difference.

    Leaf material has twosidedsign multiplied with supplied normal map wired to the normal map.

    Any ideas?

    Thank you.

  • #2
    Hrmm... Make sure you disable the automatic lightmap UV generation. Open the static mesh and in every LOD, uncheck that option if it is enabled and click apply. When that is on, it generates new UVs and doesn't use the ones made/tuned in the SpeedTree Modeler. The automatic ones will most likely be pretty bad in comparison to the ones you make in the Modeler. In UE4.6, that should be disabled by default for SpeedTrees.


    • #3
      That was it!


      • #4
        Hello, i have the exact same problem on the free Broadloaf Desktop Tree.
        Automatic Lightmap UV is off by default for each LOD (UE4 v4.7.2), UV Channel 1 are ok, sun is Stationnary for the dynamic shadows.
        Maybe some translucent material i should apply on the leaves?


        • #5
          If you changed the materials, make sure you have the two-sided sign node being used with the normal map, like how the importer creates it. This is to account for how UE4 lights two-sided materials.

          Also be sure your level has a lightmass importance volume to control the quality of lightmass building.

          You could switch to the new two sided foliage shader that uses subsurface scattering to light more like real foliage would. It is a little more expensive, but often results in better looking foliage.


          • #6
            The material are the default imported, i've checked and they effectively use the two-sided sign node.
            Thanks a lot to have mentionned the lightmass importance volume, or i'd never have thought to scale it up

            I've just resolved my pb, and in fact it was not the same than Knacker. I was messing to have the proper GI and Dynamic shadows

            Thanks for your fast help, i just subscribed just a few hours ago, and i already have the proper workflow for amazing results...