Is it possible to duplicate a collection from a Python script? When I do it manually, the Console shows bpy.ops.outliner.collection_duplicate(), however if I call it from script, there is a problem with context:
RuntimeError: Operator bpy.ops.outliner.collection_duplicate.poll() failed, context is incorrect
Does that mean that collection_duplicate() can be called only from the Outliner editor? If so, how to 'fake' it from a script?
API method
If you know the collection you wish to dupe, and the collection you wish to parent to, consider something like below. Because a collection can have many parents, I'm not totally sure without using the outliner how to determine which instance of the collection is being duped, and hence where in the hierarchy to paste.
As a test, I've copied the context collection to to the scene collection, with and without linked data. Using a method that recursively creates a new collection and populates it with object copies from the source.
EDIT. Have added a look up table with original -> dupe to change a dupes parent to a dupe (if duped). Other things to consider here are driver variable targets, constraint objects, modifier objects.
import bpy
from collections import defaultdict
def copy_objects(from_col, to_col, linked, dupe_lut):
for o in from_col.objects:
dupe = o.copy()
if not linked and o.data:
dupe.data = dupe.data.copy()
to_col.objects.link(dupe)
dupe_lut[o] = dupe
def copy(parent, collection, linked=False):
dupe_lut = defaultdict(lambda : None)
def _copy(parent, collection, linked=False):
cc = bpy.data.collections.new(collection.name)
copy_objects(collection, cc, linked, dupe_lut)
for c in collection.children:
_copy(cc, c, linked)
parent.children.link(cc)
_copy(parent, collection, linked)
print(dupe_lut)
for o, dupe in tuple(dupe_lut.items()):
parent = dupe_lut[o.parent]
if parent:
dupe.parent = parent
test call
context = bpy.context
scene = context.scene
col = context.collection
print(col, scene.collection)
assert(col is not scene.collection)
parent_col = context.scene.collection
copy(scene.collection, col)
and linked copy
copy(scene.collection, col, linked=True)
Note
For a totally linked copy, ie the objects and collections within are linked copies then
cc = collection.copy()
will do the trick.
Related
This will duplicate the active collection in the outliner:
import bpy
for window in bpy.context.window_manager.windows:
screen = window.screen
for area in screen.areas:
if area.type == 'OUTLINER':
override = {'window': window, 'screen': screen, 'area': area}
bpy.ops.outliner.collection_duplicate(override)
break
From the documentation example here: Execution Context
After a lot of trial and error (mostly error) here is a routine I came up with to copy one collection to a new collection by name. You can copy the inner objects as linked objects with the third parameter.
def duplicateCollectionByName(origName,newName,linked=False):
original_collection = bpy.data.collections[origName]
new_collection = bpy.data.collections.new(newName)
bpy.context.scene.collection.children.link(new_collection)
new_index=len(bpy.context.scene.collection.children)
bpy.ops.object.select_all(action='DESELECT')
for obj in original_collection.objects:
obj.select_set(True)
bpy.ops.object.duplicate_move_linked(OBJECT_OT_duplicate={"linked":linked, "mode":'TRANSLATION'})
bpy.ops.object.move_to_collection(collection_index=new_index)
return new_index
It is cool that when you perform actions in the Blender scene you can see the code spit out. Too bad it is wrong 90% of the time. Well, not "wrong", but it often uses commands that simply don't work inside python. I have performed tasks then copied/pasted that command into the console and most times it just throws an error. That is frustrating.
Here is a version I came up with. It preserves the hierarchy but does NOT copy the object data. Copy the data along the object and rebind them if you want a deep copy.
#=====================================
def clone_collection(src : Collection) -> Collection:
sc = bpy.context.scene
# create a new collection to collect copied objects
clone_collec = bpy.data.collections.new('clone')
# add the created collection to the scene
sc.collection.children.link(clone_collec)
# duplicates 'src' collection root objects recursively
for obj in src.objects:
if (obj.parent == None):
clone_object_recursive(obj, None, clone_collec)
#-------
def clone_object_recursive(obj : Object, parent: Object, clone_collec : Collection):
copy = bpy.data.objects.new(obj.name, obj.data)
copy.parent = parent
copy.matrix_local = obj.matrix_local
clone_collec.objects.link(copy)
for child in obj.children:
clone_object_recursive(child, copy, clone_collec)
