Redefinition problem of 3rd party lib when use Cupoch side by side with Open3D

Hi,

I think that in many aspects Cupoch and Open3D are really mutually complementary.  But when using both together side by side, there may issue variable redefinition error from the compiler, since both may use the same 3rd party lib in several parts? 

Perhaps, could add some flags in cmake files to  deal with it?

Thanks