XREF objects are a 3ds Max thing, not a blitz thing. Look in the Max help.
Basically, they allow you to Externally Reference (XREF) an object so you can change the object in another scene. It's usefull when multiple people are working on the same scene, or on really large scenes where you can swap out high res geometry for a lower res version.
Basically, they allow you to Externally Reference (XREF) an object so you can change the object in another scene. It's usefull when multiple people are working on the same scene, or on really large scenes where you can swap out high res geometry for a lower res version.