Need help with RBD car animation and materials.

Hello. I have a car with baked materials in blender and have import that into houdini as USD in solaris and used LOPimport to bring it into SOPs and do car rig and animation on it using the RBD car rig. When I bring it back to solaris using SOPimport, all the materials are gone. I understand that RBD is packing things. Even when i unpack it before bring it into LOPs. The materials still aren't there. I don't know how to approach this and what to do. If there's a proper approach to this then would love some explanation. Any help will be extremely helpful and appreciated.