xrif rendering and union of these to the design

[joe]

Good morning to all
I wanted to know courtesy how to do to assign materials to an external reference and if it is necessary, for this reason, to merge objects to the drawing

 

[PlannerRoad]

....and if it is necessary, for this reason, to join objects to the drawing

if you go to the external references panel, select the reference and with the right button you have the option join. He joins you as a block.