Returns the object which is driving the action or shape animation. This could be any object derived from SIObject which is driving the action or shape animation. This property is not available for compound clips. You can test to see whether the clip is a compound clip by calling the base method SIObject.IsClassOf(siClipContainerID) on the Clip object.

Warning: In the case of Expressions or Constraints, this property will fail, reporting that it is not implemented (returns E_NOTIMPL) because the MappedItem object does not contain the full Expression or Constraint objects.

// get accessor SIObject rtn = MappedItem.Source2;

MappedItem::GetAnimationSource