Thx both for your answers.
I am aware of the problems with parented moving objects to the world center.
I succeded in a working subworld after i placed an empty at the center of the subworld.
All subworld objects are parented to this empty.
The animation is the animation of this center, its moved and rotated.
The empty itself is initialy at the worldcenter.
In the subworld are objects that needs colliders. I have not any problem when i use triangle mesh colliders.
But as soon as i set a real collider, it disappears as it becomes an actor, so it does not behave the same as the object it is colliding.
Ofcoarse this collider is also parented to the subworld center empty
I will try to make a workaround by changing the colider to an object and texture this object with a pure an pure transparent png.
I will take in account what you said adam but this subworld is complete ready and absolutely the most attractive part and surprize of the age! Fully working for about a year now, only without some colliders.
I realy want to finish this age now i am able to export it again.
Still there are many things that have to be done before its ready to release.
One of those things are the popping effects calena talks about in visregions.
Its difficult to handle combined with transparent windows.
Then it also needs visual blockers.
Still a long way to go.