Railworks America

It's probably not easy but how do you add opening doors and windows to Railworks locos?

You basically can't. It's part of the Geo.

buzz456 wrote:You basically can't. It's part of the Geo.

How does DTG and developers like DTM and VRC do it when they make stuff? Do they add it when they create the GEO and such?

Yes, they make this when they make the original loco.
You can't add this later if you don't have the source file for the model, that is, if you are not the original author.

When the engine is built it has to already come that way with opening doors and windows, if not there's no way to make the windows and doors open since there is no possible way unless you are the 3d developer of that engine.