Developing .obj sequence exporter for selected objects

Polyflow

Hello i am new here.
I am developing obj files sequence exporter .
Now it properly export regular objects such as moving cube itc but skinned meshes stuck in one pose over all frames.
I found not so elegant solution - Bake it as Alembic before export skinned mesh . Any options to export skinning meshes wihtout prebaking? Or how bake objects by script?

import c4d
import os
import subprocess
from c4d import gui


#USAGE:
#1) SET TIMELINE START-END
#2) SELECT OBJECTS TO EXPORT
#3) EXECUTE SCRIPT
#4) SELECT FILENAME. FRAME NUMBER WILL BE AUTOMATICALLY ADDED TO .OBJ FILE NAMES


def main():
    c4d.StopAllThreads()
    doc = c4d.documents.GetActiveDocument()
    fps = doc.GetFps()
    fromTime = doc.GetMinTime().GetFrame(fps)
    toTime = doc.GetMaxTime().GetFrame(fps)
    animLength = toTime - fromTime + 1
    filePath = c4d.storage.SaveDialog()
    filePath, objName = os.path.split(filePath)
    objName = objName + "_"
    filePath = filePath + "\\"


    for f in range(0,animLength):

        c4d.EventAdd(c4d.EVENT_FORCEREDRAW)
        c4d.DrawViews(c4d.DRAWFLAGS_FORCEFULLREDRAW)
        c4d.StatusSetText("Exporting " + str(f) + " of " + str(animLength))
        c4d.StatusSetBar(100.0*f/animLength)

        objs = doc.GetActiveObjects(c4d.GETACTIVEOBJECTFLAGS_CHILDREN)

        # Get a fresh, temporary document with only the selected objects
        docTemp = c4d.documents.IsolateObjects(doc, objs)
        docTemp.SetTime(c4d.BaseTime(fromTime,fps) + c4d.BaseTime(f,fps))
        if docTemp == None:
            return

        # Set project scale
        unitScale = c4d.UnitScaleData()
        unitScale.SetUnitScale(1.0, c4d.DOCUMENT_UNIT_M)

        bc = c4d.BaseContainer()
        bc[c4d.DOCUMENT_DOCUNIT] = unitScale
        docTemp.SetDocumentData(c4d. DOCUMENTSETTINGS_DOCUMENT, bc)


        fileName = filePath+objName+str(f)+".obj"
        savingresult = c4d.documents.SaveDocument(docTemp,fileName,c4d.SAVEDOCUMENTFLAGS_0,c4d.FORMAT_OBJ2EXPORT)
        c4d.documents.KillDocument(docTemp)

    c4d.StatusClear()
    gui.MessageDialog( 'Exporting to'+filePath+' done' )


if __name__=='__main__':
    main()

a_block

Hello @Polyflow,

welcome to the Plugin Café

Setting time via SetTime() basically just sets the time value in the document. But C4D also needs to evaluate the scene at that moment in time. This is done by calling ExecutePasses().

DrawViews() can indeed do the same (and more) for you, but in your case it should not be needed, ExecutePasses() should be fine. See for example this thread for some discussion on this topic: python plugin for every frame

So, in your code, you probably also need to "execute" the temporary document.

There's some more information on this in our C++ SDK manuals. I know, we are talking Python here, but maybe it's interesting anyway: BaseDocument manual - Time

Cheers,
Andreas

mikeudin

May be Polygonize can help you.

Make a clone of the document and turn all objects into polygon based objects.

a_block

I'm afraid I need to apologize, my answer was actually by some discussion we had internally and I was too confused to read properly again. Sorry. Maybe @mikeudin's answer can already help. We'll look into this tomorrow again.

a_block

Hello @Polyflow,

we thought a bit more about your request. Unfortunately I had no time, yet, to do some tests here.
In general we think, my last answer should at least be part of a solution of the problem.

In regards to "polygonizing" or "baking", this should actually be just a matter of correctly retrieving the cache of an object in the executed document. Please take a look at GetDeformCache() and GetCache(). Again also the C++ docs have some more info on this: BaseDocument manual - Cache.

Cheers,
Andreas

Polyflow

@mikeudin
Polygonize not works for me.

By the way - I'm amazed at the responsiveness of your community.

Polyflow

Now i am trying to Bake an object before export using Current State To Object but this test piece of code not do anything

res = utils.SendModelingCommand(command = c4d.MCOMMAND_CURRENTSTATETOOBJECT,
                                list = [op],
                                mode = c4d.MODELINGCOMMANDMODE_ALL,
                                doc = doc)
    c4d.EventAdd()

mp5gosu

Hi @Polyflow,
did you try the example here? Also, please keep an extra eye on the note that's written below there.
You have to first clone your object via GetClone() and pass this as to your object list.
For example, I'm using this code in one of my plugins at work (there's a lot of error-handling stuff missing though):

# current state to object
def csto(op):
    if op is None:
        return False

    doc = op.GetDocument()

    if doc is None:
        return False

    pred = op.GetPred()
    parent = op.GetUp()

    settings = c4d.BaseContainer()
    settings.SetBool(c4d.MDATA_CURRENTSTATETOOBJECT_INHERITANCE, True)
    newOp = c4d.utils.SendModelingCommand(command=c4d.MCOMMAND_CURRENTSTATETOOBJECT,
                                          mode=c4d.MODELINGCOMMANDMODE_ALL,
                                          list=[op.GetClone()],
                                          doc=doc,
                                          bc=settings)

    if newOp:
        doc.AddUndo(c4d.UNDOTYPE_NEW, newOp[0])
        doc.InsertObject(newOp[0], parent, pred)
        c4d.EventAdd()
        return True

    return False

and

for polygonizing the document:

# Polygonize document, respecting instances in the right order, returns new document
def polygonize(doc):
    if doc is None:
        return None

    op = doc.GetFirstObject()
    oldObjects = []

    while op:
        if op.IsInstanceOf(c4d.Oinstance):
            # check and convert instances
            oldObjects.append(op)
            csto(op)

        op = GetNextObject(op)

    for op in oldObjects:
        doc.AddUndo(c4d.UNDOTYPE_DELETE, op)
        op.Remove()

    return doc.Polygonize()

You have to resolve the instances before using this code, though.
Hope, this helps you a bit.

Polyflow

@mp5gosu i am unsuccessfully trying code from documentation.

I’m the developer of Vertex Animation Tools for Unity, I can’t say that I'm new to tool development, but this API makes me feel stupid. I saw the Polygonyze function, but I don’t see its result. I'm really trying to understand the C4D API in reasonable term but I can't. Exporting the obj sequence from c4d is a trivial function that people have been looking for for years, and now I understand why.
Can Maxons engineers helps to write this script (finally)?

mikeudin

To see the results of Poligonize method you have to insert resulting document.

a_block

@Polyflow: MAXON's SDK Team can only help and assist you in achieving your goal. Writing complete scripts and plugins is not within our mandate.

With that said, what about my answer regarding caches? Can you give us some more details on the issues you have with this approach?

Cheers,
Andreas

bentraje

Probably not that helpful but there is an existing script for the C4D OBJ Sequence Exporter
https://richh.co/c4d-native-obj-sequence-export-no-plugins/