I was thinking of creating a backpack morph prop but have not had a chance to do it yet...
For simple animations you can construct the prop from multiple parts and then use regular iClone move and rotate functions to open it.
For a more complex but integrated solution you can use a boned prop which has "bones" allowing the prop to be opened and closed by moving the appropriate bone.
For complex actions - including two stage actions - you can use a Morph prop. Morph props are props that are implemented as characters so that you can apply morphs to them using Expressions (via Face Puppet).
You can find multiple examples of Morph Props in my store (
Lord Ashes' Warehouse) such as
As you can see, a Morph prop can change shape drastically, well beyond that of what one can do with simple translation, rotation and scaling.
"We often compare ourselves to the U.S. and often they come out the best, but they only have the right to bear arms while we have the right to bare breasts"
Bowser and Blue, Busting The Breast