SOLVED AddUndo() for MergeDocument() ?

@m_magalhaes
No, this solution does not work for me. I am trying to add UNDO when importing an OBJ file.

hi,

Getting the example from our github repository and adding the undo part for the document.
if it's not working, could you provide the scene ? Or maybe your code ?

"""
Copyright: MAXON Computer GmbH
Author: Joey Gaspe
Description:
    - Imports Obj with custom settings.
Class/method highlighted:
    - c4d.plugins.FindPlugin()
    - MSG_RETRIEVEPRIVATEDATA
    - c4d.documents.MergeDocument()
Compatible:
    - Win / Mac
    - R13, R14, R15, R16, R17, R18, R19, R20, R21
"""
import c4d


def main():
    # Retrieves a path to load the imported file
    selectedFile = c4d.storage.LoadDialog(title="Load File for OBJ Import", type=c4d.FILESELECTTYPE_ANYTHING, force_suffix="obj")
    if not selectedFile:
        return

    # Retrieves Obj import plugin, defined in R17 as FORMAT_OBJ2IMPORT and below R17 as FORMAT_OBJIMPORT
    objExportId = c4d.FORMAT_OBJIMPORT if c4d.GetC4DVersion() < 17000 else c4d.FORMAT_OBJ2IMPORT
    plug = c4d.plugins.FindPlugin(objExportId, c4d.PLUGINTYPE_SCENELOADER)
    if plug is None:
        raise RuntimeError("Failed to retrieve the obj importer.")

    data = dict()
    # Sends MSG_RETRIEVEPRIVATEDATA to OBJ import plugin
    if not plug.Message(c4d.MSG_RETRIEVEPRIVATEDATA, data):
        raise RuntimeError("Failed to retrieve private data.")

    # BaseList2D object stored in "imexporter" key hold the settings
    objImport = data.get("imexporter", None)
    if objImport is None:
        raise RuntimeError("Failed to retrieve BaseContainer private data.")

    # Defines the settings
    objImport[c4d.OBJIMPORTOPTIONS_PHONG_ANGLE_DEFAULT] = 22.5
    objImport[c4d.OBJIMPORTOPTIONS_TEXTURECOORDINATES] = True
    objImport[c4d.OBJIMPORTOPTIONS_SPLITBY] = c4d.OBJIMPORTOPTIONS_SPLITBY_OBJECT
    objImport[c4d.OBJIMPORTOPTIONS_MATERIAL] = c4d.OBJIMPORTOPTIONS_MATERIAL_MTLFILE
    objImport[c4d.OBJIMPORTOPTIONS_POINTTRANSFORM_FLIPZ] = True

    # Finally imports without dialogs
    # Start undo for the document
    doc.StartUndo()
    # Add the document to the stack
    doc.AddUndo(c4d.UNDOTYPE_CHANGE, doc)
    if not c4d.documents.MergeDocument(doc, selectedFile, c4d.SCENEFILTER_OBJECTS | c4d.SCENEFILTER_MATERIALS, None):
        raise RuntimeError("Failed to load the document.")
    # Finish the building of undo
    doc.EndUndo()
    # Pushes an update event to Cinema 4D
    c4d.EventAdd()


if __name__ == '__main__':
    main()

cheers,
Manuel

Hi,

@m_magalhaes solution should work just fine with obj files too. If you are getting no output you probably haven't escaped special characters in your file path properly. Alternatively you could also pass a raw string (then you don't have to escape special characters).

file_path = r"C:\myfile.c4d

The reason why your script is not working as expected is probably because you are only adding Undos for the selected objects. However only the last object that has been merged into the document will be selected after the merge operation.

Cheers
zipit

@m_magalhaes

here is my code

import c4d
from c4d import utils, documents, plugins

import time
from threading import Thread


class WatchThread(Thread):
    def __init__(self, name, doc):
        Thread.__init__(self, name=name)
        self.doc = doc

    def run(self):
        while True:
            time.sleep(2.5)
            obj_importer(self.doc, r'f:\01.obj')
            print 'Loaded.',
            break


def obj_importer(doc, obj_path):
    if obj_path is None:
        return

    plug = plugins.FindPlugin(1030177, c4d.PLUGINTYPE_SCENELOADER)
    if plug is None:
        return

    op = {}
    if plug.Message(c4d.MSG_RETRIEVEPRIVATEDATA, op):

        if "imexporter" not in op:
            return

        obj_import = op["imexporter"]
        if obj_import is None:
            return

        # Parameters
        obj_import[c4d.OBJIMPORTOPTIONS_POINTTRANSFORM_SWAPXY] = False
        obj_import[c4d.OBJIMPORTOPTIONS_POINTTRANSFORM_SWAPXZ] = False
        obj_import[c4d.OBJIMPORTOPTIONS_POINTTRANSFORM_SWAPYZ] = True

        doc.StartUndo()
        doc.AddUndo(c4d.UNDOTYPE_CHANGE, doc)

        # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

        c4d.documents.MergeDocument(doc, obj_path,
                                    c4d.SCENEFILTER_OBJECTS |
                                    c4d.SCENEFILTER_MATERIALS |
                                    c4d.SCENEFILTER_MERGESCENE, None)

        # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

        doc.EndUndo()

        obj_import[c4d.OBJIMPORTOPTIONS_PRESETS] = 0

    c4d.StatusClear()
    c4d.EventAdd()


if __name__ == '__main__':
    doc = c4d.documents.GetActiveDocument()
    wt = WatchThread('ht', doc)
    wt.start()

Hi,

first of all: If you want to use threads, you should use c4d.threading.C4DThread and not Pythons builtin thread type or weird things might happen. Also note that threading comes with certain limitations:

For all threaded functions it is forbidden to:

  • Add an event.
    [...]
  • Change the structure of objects attached to the document.
    [...]
  • Create undos.

I am also not quite sure what the purpose of your thread is, since you are loading into the active document. If you want to "load in the background" you will have to use a temporary document. But for loading just one file I do not see any performance benefits, since you have to merge that temporary document into the active document at the end.

Cheers
zipit

hello,

well as @zipit said it's forbidden to change the structure of a document outside the main thread.
watch this page and the warning about threading

I did checked the StartUndo and it's using GeIsMainThreadAndNoDrawThread and just get out.
So it's pretty clear that you can't add undo on a thread.

why are you using thread here ?

Cheers,
Manuel

This post is deleted!

@m_magalhaes @zipit
I use thread to manipulate external pipes(subprocess etc).

@arsen said in AddUndo() for MergeDocument() ?:

@m_magalhaes @zipit
I use thread to manipulate external pipes(subprocess etc).

Hi,

although I am aware of the concept of pipes, this does not really clear anything up for me 🧐. What do you mean by external and manipulate? Just for clarification: Under pipes I understand a data IO interface to communicate between different processes, provided in Python for example by os.pipe().

And I don't really get why this forces you to use a thread to import an obj file 🤔.

Cheers
zipit

@zipit
Hi
I use thread to track the external file. When a file is changed, it is imported.
When using c4d.threading, subprocess.Popen() / time.sleep() freezes C4D ( until the process is complete )

Hi,

ah, ok, I do understand your problem better now ;). Well as explained in this thread your cannot load files other than from the main thread of c4d.

You could do however the following:

  1. Use processes, threads or whatever you would like to use to monitor the status of your file(s).
  2. Use some cross-process communication interface like os.pipe() to indicate when your data has changed.
  3. Implement 1. and 2. within a MessageData plugin.
  4. Use MessageData.GetTimer and MessageData.CoreMessage to periodically peek into your pipe and then react to its status from the main thread/ the c4d process.

Cheers
zipit

hello,

@zipit already make another nice answer.

I can just add that in c++ you have also a filemonitor manual where you can use the function WatchDirectory

Cheers,
Manuel

@zipit @m_magalhaes
Thanks for the answers! I figured out how to solve the problem.

hi,

nice, feel free to share your solution and mark this thread as solved.

Cheers,
Manuel