File import and doc merge -> InsertAfter or c4d.PREF_INTERFACE_I_BOTTOM

mogh

Dear Team,
I am trying to import files and place them in the object tree in the right order,

i tried to set the preferences with c4d.PREF_INTERFACE_I_BOTTOM before import but it did not change my order.

        interface_preferences = c4d.GetWorldContainer()
        previous_insert_at = interface_preferences.GetInt32(c4d.PREF_INTERFACE_INSERTAT)
        interface_preferences.SetInt32(c4d.PREF_INTERFACE_INSERTAT, c4d.PREF_INTERFACE_I_BOTTOM, )

Is there a convenient way or do i need to move the "node" manually to the bottom on each import ...
or more universal for me is there a way to sort root nodes in the Object manager tree ? (only found an old coffee thread ... )
thanks in advance ...
mogh

Anlv

import c4d

doc: c4d.documents.BaseDocument  # The currently active document.
op: c4d.BaseObject | None  # The primary selected object in `doc`. Can be `None`.

def main() -> None:

    obj = c4d.BaseObject(c4d.Ocube)

    # Insert after the last root object.
    roots = doc.GetObjects()
    doc.InsertObject(obj, pred=roots[-1] if roots else None)

    c4d.EventAdd()
    
if __name__ == '__main__':
    main()

Hope this helps.
Here is another example that can directly execute the import

import c4d

def main():
    doc = c4d.documents.GetActiveDocument()
    path = c4d.storage.LoadDialog(
        c4d.FILESELECTTYPE_SCENES,
        "Import Scene"
    )
    if not path:
        return

    roots = doc.GetObjects()
    anchor = roots[-1] if roots else None
    old_guids = {obj.GetGUID() for obj in roots}

    flags = (
        c4d.SCENEFILTER_OBJECTS |
        c4d.SCENEFILTER_MATERIALS |
        c4d.SCENEFILTER_MERGESCENE |
        c4d.SCENEFILTER_DIALOGSALLOWED
    )

    c4d.StopAllThreads()
    doc.StartUndo()

    try:
        doc.AddUndo(c4d.UNDOTYPE_CHANGE, doc)

        if not c4d.documents.MergeDocument(doc, path, flags, None):
            c4d.gui.MessageDialog("Import failed.")
            return

        # Find the newly imported root objects.
        imported = [
            obj for obj in doc.GetObjects()
            if obj.GetGUID() not in old_guids
        ]

        # Move them below the previous last root object.
        if anchor:
            for obj in imported:
                matrix = obj.GetMg()
                doc.AddUndo(c4d.UNDOTYPE_CHANGE, obj)
                obj.Remove()
                obj.InsertAfter(anchor)
                obj.SetMg(matrix)
                anchor = obj
    finally:
        doc.EndUndo()
        c4d.EventAdd()

if __name__ == "__main__":
    main()

Cheers,
Anlv

ferdinand

Hey @mogh,

let me clarify things first a bit.

Reproduce:

You have a scene A in an alien scene format such as FBX or OBJ.
You have an existing native Cinema 4D scene B.
You are trying to merge A into B.

Result:
The objects of A appear before the objects of B in the scene hierarchy of the merged scene. Even when you change the insertion order in Preferences > Interface.

First of all, it is not very surprising that "insert at" does not work (and "paste at" does neither), because these are for individual objects within a scene, not for merging entire scenes. What you are effectively missing is a scene merge order option and this does not really have something to do with importers. This would be addressed best by a feature request in our Support Center.

With a pinch of Python, you can solve this yourself as demonstrated by @Anlv (thanks!). Using BaseList2D.GetGUID as @Anlv did is okay, but the more native solution would be hash(obj), i.e., C4DAtom.__hash__. Scene elements are for quite a while now natively hashable, so you can for example do this:

roots: set[int] = { hash(obj) for obj in doc.GetObjects() }
new_roots: set[int] = roots.intersection({ hash(obj) for obj in new_doc.GetObjects() })

And it will give you the set of all root level hashes (GeMarker IDs). I think also the transform copying @Anlv does at the end of the script should not be necessary, because these are root level objects, and therefore removing and re-adding them will not affect their transforms (as they have no parents to which their transform would be relative to). But I have not run @Anlv's full script myself, so it could be that I am overlooking something.

Cheers,
Ferdinand

Anlv

@ferdinand Thanks for pointing that out. Indeed, matrix = obj.GetMg() and obj.SetMg(matrix) are not necessary; this is leftover code from when it was previously used to insert into the child or sibling level of the selected object.

Cheers,
Anlv