I have an update.
One of our devs did a deep dive, and here’s what he found: here’s what’s happening :
The areas where grass is missing are all located near Fortnite “buildings”, and those in-game automatically spawn a “grass exclusion box” to remove landscape grass wherever they overlap with the landscape.
Once in-game, you end up with those large landscape grass exclusion areas that make it look like grass is partly updated, but it’s actually the expected behavior. The workarounds are :
- If possible, rotate/scale the object such that its axis-aligned (blue) bounding box more closely matches the object.
- Use basic static meshes rather than FN “buildings”, since static meshes don’t come with that grass exclusion box behavior. If the user authors his own meshes (rather than reusing the buildings we provide), that might be an option, but it also means grass will not be excluded at all within those meshes anymore.
- Manually spawn grass instances in the areas where it’s missing (e.g., using the Foliage mode). These are unaffected by the landscape grass exclusion boxes, so this allows the user to compensate.
The dev will follow up with another team to see if anything can be done to expose the bounds visualization, but you will see the bug reporter respond that this is working as intended.