Hi @bentraje,

In order to support undo, you should encapsulate all your calls of BaseDocument.AddUndo with BaseDocument.StartUndo and BaseDocument.EndUndo
Moreover, take care depending on the operation you are doing, BaseDocument.AddUndo has to be called before or after your operation. Take a look at the documentation to know more.

Typically StartUndo, defines the state of the scene to be reverted when pressing undo. And EndUndo the state of the scene to be reverted when pressing re-do after an undo.
AddUndo then record all the changes that you want to store in this undoing.

Which will give us something like:

import c4d

# Main function
def main():
    # Create the BaseContainer to define the tool settings
    settings = c4d.BaseContainer()  
    
    # Explicitly say we will not use point, so the center will be used
    settings[c4d.MDATA_WELD_TOPOINT] = False
    
    doc.StartUndo()
	
    doc.AddUndo(c4d.UNDOTYPE_CHANGE, op)
    # Execute the SendModelingCommand
    res = c4d.utils.SendModelingCommand(command = c4d.ID_MODELING_WELD_TOOL,
                                    list = [op], 
                                    mode = c4d.MODELINGCOMMANDMODE_POLYGONSELECTION, 
                                    bc = settings, 
                                    doc = doc)
                                    
    doc.EndUndo()
	
    # Update the scene
    c4d.EventAdd()

# Execute main()
if __name__=='__main__':
    main()

To find more information about how ID_MODELING_WELD_TOOL works, you can have a look at this topic.

If you have any question, please let me know.
Cheers,
Maxime.

Hi @anoano.

I will need more information.
I'm not sure in which context you are, when you say virtual object I think you refer to be inside of a Generator and the GetVirtualObjects method isn't?

Moreover, when you say a link, you refer to a LinkBox parameter, so the linked object can be anywhere and not necessary a Child of the current Generator, isn't?

Last stuff, please make sure to mark your topic as a question. I've done it for this time (don't worry you are new, no issue at all), see Q&A New Functionality.

Cheers,
Maxime.

Unfortunately, Cinema 4D does not track this, and there is no way to know it currently since Cinema 4D is almost a portable application (you can copy/paste Cinema 4D folder to anywhere as long as dependencies have been installed once it will work).

In any case, it's a request we already made to our development team, I'll push the topic again and will see .
Cheers,
Maxime.

@merkvilson, sorry this code is planned to be part of our github, so like any of our examples, they are under the Apache License.

For more information see Apache License from our Github repository.
Cheers,
Maxime.

Hi @merkvilson thanks for reaching us,

Here is a script to retrieves the Cinema 4D preference folder of a specific installation stored in temp folder working from R17 to R20.

"""
Copyright: MAXON Computer GmbH
Author: Maxime Adam

Description:
    - Retrieves the path of the preference folder according to an installation path without the need to launch Cinema 4D.

Note:
    - From Cinema 4D c4d.storage.GeGetC4DPath(c4d.C4D_PATH_STARTUPWRITE) can be called to retrieves the current installation path.

Compatible:
    - Win / Mac
    - R17, R18, R19, R20
"""
import os
import platform


def CRC(rawString):
    # Performs CRC 32 BIT on the input byte
    crc = 0xffffffff

    crc32tab_o32 = [
        0x00000000, 0xf26b8303, 0xe13b70f7, 0x1350f3f4, 0xc79a971f, 0x35f1141c, 0x26a1e7e8, 0xd4ca64eb,
        0x8ad958cf, 0x78b2dbcc, 0x6be22838, 0x9989ab3b, 0x4d43cfd0, 0xbf284cd3, 0xac78bf27, 0x5e133c24,
        0x105ec76f, 0xe235446c, 0xf165b798, 0x030e349b, 0xd7c45070, 0x25afd373, 0x36ff2087, 0xc494a384,
        0x9a879fa0, 0x68ec1ca3, 0x7bbcef57, 0x89d76c54, 0x5d1d08bf, 0xaf768bbc, 0xbc267848, 0x4e4dfb4b,
        0x20bd8ede, 0xd2d60ddd, 0xc186fe29, 0x33ed7d2a, 0xe72719c1, 0x154c9ac2, 0x061c6936, 0xf477ea35,
        0xaa64d611, 0x580f5512, 0x4b5fa6e6, 0xb93425e5, 0x6dfe410e, 0x9f95c20d, 0x8cc531f9, 0x7eaeb2fa,
        0x30e349b1, 0xc288cab2, 0xd1d83946, 0x23b3ba45, 0xf779deae, 0x05125dad, 0x1642ae59, 0xe4292d5a,
        0xba3a117e, 0x4851927d, 0x5b016189, 0xa96ae28a, 0x7da08661, 0x8fcb0562, 0x9c9bf696, 0x6ef07595,
        0x417b1dbc, 0xb3109ebf, 0xa0406d4b, 0x522bee48, 0x86e18aa3, 0x748a09a0, 0x67dafa54, 0x95b17957,
        0xcba24573, 0x39c9c670, 0x2a993584, 0xd8f2b687, 0x0c38d26c, 0xfe53516f, 0xed03a29b, 0x1f682198,
        0x5125dad3, 0xa34e59d0, 0xb01eaa24, 0x42752927, 0x96bf4dcc, 0x64d4cecf, 0x77843d3b, 0x85efbe38,
        0xdbfc821c, 0x2997011f, 0x3ac7f2eb, 0xc8ac71e8, 0x1c661503, 0xee0d9600, 0xfd5d65f4, 0x0f36e6f7,
        0x61c69362, 0x93ad1061, 0x80fde395, 0x72966096, 0xa65c047d, 0x5437877e, 0x4767748a, 0xb50cf789,
        0xeb1fcbad, 0x197448ae, 0x0a24bb5a, 0xf84f3859, 0x2c855cb2, 0xdeeedfb1, 0xcdbe2c45, 0x3fd5af46,
        0x7198540d, 0x83f3d70e, 0x90a324fa, 0x62c8a7f9, 0xb602c312, 0x44694011, 0x5739b3e5, 0xa55230e6,
        0xfb410cc2, 0x092a8fc1, 0x1a7a7c35, 0xe811ff36, 0x3cdb9bdd, 0xceb018de, 0xdde0eb2a, 0x2f8b6829,
        0x82f63b78, 0x709db87b, 0x63cd4b8f, 0x91a6c88c, 0x456cac67, 0xb7072f64, 0xa457dc90, 0x563c5f93,
        0x082f63b7, 0xfa44e0b4, 0xe9141340, 0x1b7f9043, 0xcfb5f4a8, 0x3dde77ab, 0x2e8e845f, 0xdce5075c,
        0x92a8fc17, 0x60c37f14, 0x73938ce0, 0x81f80fe3, 0x55326b08, 0xa759e80b, 0xb4091bff, 0x466298fc,
        0x1871a4d8, 0xea1a27db, 0xf94ad42f, 0x0b21572c, 0xdfeb33c7, 0x2d80b0c4, 0x3ed04330, 0xccbbc033,
        0xa24bb5a6, 0x502036a5, 0x4370c551, 0xb11b4652, 0x65d122b9, 0x97baa1ba, 0x84ea524e, 0x7681d14d,
        0x2892ed69, 0xdaf96e6a, 0xc9a99d9e, 0x3bc21e9d, 0xef087a76, 0x1d63f975, 0x0e330a81, 0xfc588982,
        0xb21572c9, 0x407ef1ca, 0x532e023e, 0xa145813d, 0x758fe5d6, 0x87e466d5, 0x94b49521, 0x66df1622,
        0x38cc2a06, 0xcaa7a905, 0xd9f75af1, 0x2b9cd9f2, 0xff56bd19, 0x0d3d3e1a, 0x1e6dcdee, 0xec064eed,
        0xc38d26c4, 0x31e6a5c7, 0x22b65633, 0xd0ddd530, 0x0417b1db, 0xf67c32d8, 0xe52cc12c, 0x1747422f,
        0x49547e0b, 0xbb3ffd08, 0xa86f0efc, 0x5a048dff, 0x8ecee914, 0x7ca56a17, 0x6ff599e3, 0x9d9e1ae0,
        0xd3d3e1ab, 0x21b862a8, 0x32e8915c, 0xc083125f, 0x144976b4, 0xe622f5b7, 0xf5720643, 0x07198540,
        0x590ab964, 0xab613a67, 0xb831c993, 0x4a5a4a90, 0x9e902e7b, 0x6cfbad78, 0x7fab5e8c, 0x8dc0dd8f,
        0xe330a81a, 0x115b2b19, 0x020bd8ed, 0xf0605bee, 0x24aa3f05, 0xd6c1bc06, 0xc5914ff2, 0x37faccf1,
        0x69e9f0d5, 0x9b8273d6, 0x88d28022, 0x7ab90321, 0xae7367ca, 0x5c18e4c9, 0x4f48173d, 0xbd23943e,
        0xf36e6f75, 0x0105ec76, 0x12551f82, 0xe03e9c81, 0x34f4f86a, 0xc69f7b69, 0xd5cf889d, 0x27a40b9e,
        0x79b737ba, 0x8bdcb4b9, 0x988c474d, 0x6ae7c44e, 0xbe2da0a5, 0x4c4623a6, 0x5f16d052, 0xad7d5351]

    for s in rawString:
        k = ord(s)
        crc = crc32tab_o32[(crc & 0xff) ^ (k & 0xff)] ^ (crc >> 8)
        k >>= 8
        crc = crc32tab_o32[(crc & 0xff) ^ (k & 0xff)] ^ (crc >> 8)
        k >>= 8
        crc = crc32tab_o32[(crc & 0xff) ^ (k & 0xff)] ^ (crc >> 8)
        k >>= 8
        crc = crc32tab_o32[(crc & 0xff) ^ (k & 0xff)] ^ (crc >> 8)

    return format(crc ^ 0xffffffff, 'x').upper()


def GetTempFolder(instalDir):
    # Retrieves the temp folder
    tempFolder = None
    if platform.system() == "Windows":
        tempFolder = os.getenv('APPDATA')
    elif platform.system() == "Darwin":
        libPath = os.path.expanduser('~/Library')
        tempFolder = os.path.join(libPath, "Preferences")

    if not os.path.exists(tempFolder) or tempFolder is None:
        raise RuntimeError("Failed to retrieves appdata folder.")

    # Cleanups the input path
    instalDir = os.path.normpath(instalDir)
    instalDir = instalDir.replace('\\\\', '\\')
    parentDirLower = instalDir.lower()

    # Retrieves only the name of the last folder
    parentName = os.path.split(instalDir)[1]
    if not parentName:
        raise RuntimeError("Failed to retrieves parent Name folder")

    parentName = parentName.replace(':', '_')

    # Computes the crc of the dir in lowercase.
    crc = CRC(parentDirLower)

    # Builds the final path
    finalPath = os.path.join(tempFolder, "MAXON", parentName + "_" + crc)

    return finalPath


def main():
    # Path must be in unicode, it can be retrieved from c4d with c4d.storage.GeGetStartupPath()
    winInstallationPath = unicode("C:\Program Files\MAXON\Cinema 4D R20")
    macInstallationPath = unicode("/Users/m_adam/Application/MAXON/Cinema 4D R20")
    print "Path:", GetTempFolder(winInstallationPath)


if __name__ == '__main__':
    main()

As a side note in R20 plugins can be installed everywhere as long as the path is set in the preferences.
And finally, there is no reliable way to know where Cinema 4D is installed from outside of Cinema 4D.

If you have any question, please let me know.
Cheers,
Maxime.

Hi @pim, the usual way is to write data in the BaseContainer of the object so they will be automatically saved in the BaseObject, then in your init you can check if the data exists in this BaseContainer and if its the case restore them.
While its the preferred way, it's not always possible since BaseContainer only supports predefined Type.

Another solution is to override NodeData.Read / Write methods. NodeData.Read will be called at the opening of the file, NodeData.Write will be called when the file is saved. You can find a more complete manual in the C++ documentation NodeData::Read() / NodeData::Write() Manual.

Additionally, you may want to override NodeData.CopyTo, this method will be called each time the user copy a TagData, so you can reset your list for example. You can find more information in the C++ documentation NodeData::CopyTo() Manual.

If you have any questions, please let me know.
Cheers,
Maxime.

Hi @pim,

The main issue is the scope, defining distances as you did, defines distances in the scope of the object AFONTTAG (the class object, not the instance). So it's shared between each instance since distance becomes an attribute of the object, and due to the nature of list in python data are shared(see http://interactivepython.org/runestone/static/CS152f17/Lists/ListsareMutable.html).

To fix that defines your variable in the scope of your instance.

class AFONTTAG(plugins.TagData):
    def __init__(self):
        self.distances = []

Cheers,
Maxime.

Hi, I updated the previous script to fix the issue.

The main problem was in GetCloneSpline in order to make a clone of the object (a Current state to object) you need to insert it into a document, but I inserted it (the tracer) into a new document, so the tracer lost its link with its particle emitter and result in an empty tracer. Inserting the clone directly into the correct document fix the issue (see line 120 and 133 for the cleanup)

I also fixed another issue regarding position while making an object editable.
There is actually a bug in the Tracer object and the command make object editable, if it's set to global position mode.
The last point will be in the generator space so that means it will break the curve if the tracer and op are not in 0,0,0..
Unfortunately, nothing can be done here, but editing the tracer object first then the generator makes it works, or you can use Current State To Object command instead.

Cheers,
Maxime.

Hi, @Aaron I'm not able to reproduce here, could you share a code example, please.

Cheers,
Maxime.

Hi, @d_schmidt I' sorry for the time needed, unfortunately, I was pretty busy this week and didn't get the time to look at your post.
As you can see in the next gift I'm not able to reproduce your issue, could you please send a c4d file. And let me know which version exactly you are using.

Cheers,
Maxime.