Duplicate 3D faces - HELP

[Anonymous]

Morning, 

I have a triangulation thats all on the same layer (all in black) i have slowly started to separate it and place different items onto its own drawing (houses, roads, etc) (in green)

I was wondering there was a way I could copy (on top of the exsisting triangluation) or even xref in and delete the duplicates 

so instead of slowly selecting each section i can do it in bulk.

so delete what is black under the green.

I've attached some pictures which should hopefully explain

[john.uhden]

Do you have any AutoLisp or VBA experience?  To my recollection the gang here is willing to help with but not necessarily create custom routines for askers.

[john.uhden]

Maybe I am missing something, but rather than copy them, change their layer, and then delete the original, why don't you just change the layer of the originals?

[Ranjit_Singh]

I would imaging if you just pasted the new tin into the original tin it might give you a composite tin with the black and green combined. Make sure to keep copies before you try.