Append scene update shadows

Hey guys,
for a current project I splitted the scene into multiple parts. Starting with a “init” scene which only contains cameras and lights. On runtime I append the different geometries without any lights or cameras. Problem I’ve got is that the shadows doesnt seem to work. Current workaround I’ve found is creating a plane in that “init” scene, which covers the whole area where I need shadows to be.

Just wanted to ask if there is any other “proper” way to get around this? Maybe something like a “updateShadowMap” function?