The Bongo hierarchy code is based on the objects ID number that they’re given inside Rhino. When objects are copied between the files Rhino might change the object ID, because the number has to be unique (two objects can’t have the same number). This causes problems because Bongo then thinks, based on the ID numbers, that the different objects are linked that actually aren’t in the original file.

This problem will also show up if you copy/past a hierarchy animation inside the same file.

Is there a fix or a work around for this problem?

The current work around is the following:

  1. Copy the animation just once into the model.
  2. Inside the model, use the command BongoCopyChain to multiply the same animation.