def GetPrimLoadability(prim):
"""Return a tuple of (isLoadable, isLoaded) for 'prim', according to
the following rules:
A prim is loadable if it is active, and either of the following are true:
* prim has a payload
* prim is a model group
The latter is useful because loading is recursive on a UsdStage, and it
is convenient to be able to (e.g.) load everything loadable in a set.
A prim 'isLoaded' only if there are no unloaded prims beneath it, i.e.
it is stating whether the prim is "fully loaded". This
is a debatable definition, but seems useful for usdview's purposes."""
if not (prim.IsActive() and (prim.IsGroup() or prim.HasPayload())):
return (False, True)
# XXX Note that we are potentially traversing the entire stage here.
# If this becomes a performance issue, we can cast this query into C++,
# cache results, etc.
for p in Usd.TreeIterator(prim, Usd.PrimIsActive):
if not p.IsLoaded():
return (True, False)
return (True, True)
