So there are a number of important Lightmass settings missing from the Foliage Tool’s Static mesh instance settings - most notably:
Use Vertex Normal for Hemisphere
Gather (This one is super important
as a lot of foliage uses bent vertex
normals to look volumetric)
Use Emissive for Static Lighting
Use Two Sided Lighting
Shadow Indirect Only
Diffuse Boost and Fully Occluded Samples Fraction on instances also
My question is why aren’t these options available for foliage instances in the Foliage Tool? Right now this is causing me a huge headache when trying to get painted foliage to look correct with static lighting and I cannot consider placing thousands of foliage meshes manually.
So after a little more digging someone suggested that you can create a new BP which inherits from FoliageInstancedStaticmesh by clicking the + next to the Component Class in the Foliage tool, and then you can edit the initial values of your class:
Unfortunately the Lightmass settings are greyed out! I have been racking my brains and trying to find help on how to fix this but have had no luck so far. I also found an interesting node in the event graph called Break LightmassPrimitiveSettings but cannot find a way to execute it. I feel like im getting closer but have found yet another roadblock.
Ok so I ended up figuring this out for myself after much pain and some help from friends - basically, the reason the Lightmass options are greyed out in the initial class values is because the mobility of the instance in the BP is set to movable by default, making the lightmass settings mute. To fix, simply scroll up the the Transform section and select “Static” from the three listed options: