This happens because unlike Forest Pack, RailClone does not consolidate materials and reassign IDs automatically. At present you need to create a Multi-Sub object material that uses the same material IDs as set on the source geometry, so the same material applied to both RailClone object and the individual components yields the same results.
In our original design for RailClone we expected material creation to be a part of the preparation to create a style. For example Forest includes the ability to consolidate materials because it's much more dependent on using multiple plants from different sources. But in RailClone each segment is usually designed uniquely for a specific style, so part of the design includes preparing the materials.
However we've had a few requests for this feature so it's now on our to-do list. Initially we would implement the same method used in Forest (create a multi-sub material on the fly), but we must evaluate carefully what side effects may be.
In any case, we want to provide a solution for this issue in the next updates.
Until we release this feature you might find this quick tip useful. If you don't want to create a multi-sub object shader and re-assign IDs manually, an easy way to consolidate materials is as follows:
- Attach all the objects into a single mesh. Use the default options, so Max creates the multi-sub object.
- Detach each object back into separate objects.
- Re-adjust the pivots if necessary.
You may find there are some scripts that can make a multi-sub object for you. For example I use RappaTools which has a Multi-Material from Selection option. This creates a multi-sub object material and automatically re=assigns the IDs. I believe the free version may have the same functionality, but we haven't tried it
I hope that helps,