I am using several environments from the Unreal Marketplace which have foliage in them. Unreal uses a single actor to represent all of the foliage painted in one go, and when the foliage covers a large area, combined with using Lumen in said area as your illumination method, when building the level it emits the following warning "InstancedFoliageActor_0 Large actor receives a pre-shadow and will cause an extreme performance hit unless bCastDynamicShadow is set to false. "
Said warning is not merely a warning, the performance impact is quite visible and goes away if one removes the foliage from the scene.
I tried finding how to change that flag but couldn’t. For a past project, removing the foliage was an option, and so we did. But for the current one it is a must, and I was wondering how to set “bCastDynamicShadow” to false. Is this an engine setting or…??? The warning does a terrible job at explaining where to configure this.