duplicate materials

[Ning_Zhou]

many duplicates, i mean same material names, anyone know the reason and how to prevent/fix/delete it easily? thanks

[Anonymous]

Can you elaborate on what your actual problem is?  Your screen capture shows that you're trying to purge elements.  Your post refers to material names.  What are you trying to prevent/fix/delete?

[Ning_Zhou]

thanks for your comment.

from my purge window, you can notice that many materials are the same, or at least material names are the same, so my question are:

1) what causes this issue? and how to prevent / fix it?

2) and eventually delete it in easy way since not easy in OOTB selection box to delete, i may have to use Dynamo