(2019-06-06, 13:59)Matt Chambers Wrote: If it was in a private library, can that library be passed along and loaded automatically when viewing an LDraw model?
In addition to what Philo already said, you can also use an MPD tool to embed the local custom parts into an MPD, so that if you share that MPD, everyone can see the parts as intended. This has the advantage of making it work for everybody, not just people who have installed the custom library.