as per this topic
As per docs - you should not add / remove / modify any elements when using
Object3D.traverse. If you need to do that - you can usechildren.forEachor save referenced to the elements you’d like to remove in an array outside of thetraverse callback.
that i read here Cannot read property 'traverse' of undefined when traverse object in scene and remove it - #2 by mjurczyk
i will try to build my fonction using ‘children.forEach’ but,
problem: where is this technique children.foreach, documented? 