Instanced or hierarchical meshes don't affect navigation

I am generating trees and other objects as instanced and hierarchical meshes but when this is done at runtime it doesn’t have any effect on navigation.

There’s a bug report here: Unreal Engine Issues and Bug Tracker (UE-150147) which might have resolved this issue for 5.1, but it only talks about foliage and not general instanced meshes or hierarchical ones. Regardless, it’s probably not out for a little while…

I’m wondering if anyone has a workaround for this at the moment?

This is quite the issue for me as well.

My game takes place in a forest with procedural foliage trees and since upgrading to UE5 the monsters are having a terrible time getting to their destinations. I’m actually surprised this made it to 5.0.

I’m planning on releasing this game later this year. Hopefully this issue is merged into release soon.

So after a lot of fiddling yesterday, I found a temporary solution… If you move the parent actor that contains all of the instances, it seems to update the navmesh. You have to actually move it at least a cm though, can’t just set it to the same position.

I’m also building a procedural forest, so it’s probably not super efficient to move all these instances, but at least it works for the moment and hopefully 5.1 will bring a fix for this.