I dont understand, how you extract these files, they were in rx3 format already or you using script?
I extract using File Master from .bigs. To extract textures you need this (it has the script to open .rx2 file textures): https://mega.nz/#!CkhVwCjL!Qlp3EPhVumWYgrpmmwLHGc9RTWbYfAspRM31A2wxrwI