Writing data to the .c4d file



  • Hello,
    I'm writing a script and I'd like to write/read data from the C4D scene file. Is this possible? If so, can you please show me to the API documentation or an example? I looked in the c4d.storage documentation, but only saw classes for external files.

    Thank you!



  • Hi,

    I am not quite sure what you mean by writing to the c4d file. However, c4d.documents contains several functions for reading and writing scene files. You are probably looking for c4d.documents.LoadDocument() and .SaveDocument().

    Cheers
    zipit



  • @zipit Hi, thanks for the reply. I mean saving to data to the scene file, not the scene file itself. For example, when I use the NitroPose plugin, it saves my data for the scene in which it's used and loads it when the file it opened.



  • Hi,

    to (de-)serialize data outside a scene document you can either use c4d's HyperFile (Link) or just use Python's own means to serialize/pickle data - like the modules json or xml. Using HyperFile has the advantage that it can serialize some cinema specific data types (everything you can put into a BaseContainer) out of the box. But it is binary, so it is not human-readable.

    It mostly depends on what it is, that you want to serialize.

    Cheers
    zipit



  • @zipit said in Writing data to the .c4d file:

    Hi,

    to (de-)serialize data outside a scene document you can either use c4d's HyperFile (Link) or just use Python's own means to serialize/pickle data - like the modules json or xml. Using HyperFile has the advantage that it can serialize some cinema specific data types (everything you can put into a BaseContainer) out of the box. But it is binary, so it is not human-readable.

    It mostly depends on what it is, that you want to serialize.

    Cheers
    zipit

    Thank you, @zipit. As I hinted at in the original post, I'd prefer not to save to an external file. When using the plugin I linked to in my last post, I don't have to load any external files. I click on the plugin tag and the poses I stored are available.

    I'm trying to find a way to get this functionality. It can just be some simple text data. Any idea how to do this?

    Thank you!



  • I suppose you mean saving data to the BaseContainer of the BaseDocument? You'll need a plugin id for that so it will not collide with the existing IDs, then you can put a sub-BaseContainer with your data into that container. Or you can define your own datatype.



  • @blastframe said in Writing data to the .c4d file:

    @zipit said in Writing data to the .c4d file:

    Hi,

    to (de-)serialize data outside a scene document you can either use c4d's HyperFile (Link) or just use Python's own means to serialize/pickle data - like the modules json or xml. Using HyperFile has the advantage that it can serialize some cinema specific data types (everything you can put into a BaseContainer) out of the box. But it is binary, so it is not human-readable.

    It mostly depends on what it is, that you want to serialize.

    Cheers
    zipit

    Thank you, @zipit. As I hinted at in the original post, I'd prefer not to save to an external file. When using the plugin I linked to in my last post, I don't have to load any external files. I click on the plugin tag and the poses I stored are available.

    I'm trying to find a way to get this functionality. It can just be some simple text data. Any idea how to do this?

    Thank you!

    Hi,

    I am more and more confused ;) So, what you actually want, is to save additional data within a c4d scene file? You can do that by registering a PluginID and then save your data under that ID in the documents BaseContainer via BaseDocument.SetDocumentData().

    Cheers
    zipit



  • Fantastic, thank you both for your help!



  • @Cairyn said in Writing data to the .c4d file:

    I suppose you mean saving data to the BaseContainer of the BaseDocument? You'll need a plugin id for that so it will not collide with the existing IDs, then you can put a sub-BaseContainer with your data into that container. Or you can define your own datatype.

    Here's what I've got so far for the sub-BaseContainer. It doesn't seem to be working. Any ideas about what I'm doing incorrectly?

    import c4d
    
    PLUGIN_ID = 1234567
    MyUniqueId = 1000001
    
    def main():
       doc = c4d.documents.GetActiveDocument()
       #get the document's BaseContainer
       bc = doc.GetDataInstance()
    
       #create a sub-BaseContainer
       subBc = c4d.BaseContainer()
       subBc[1000] = "hello"
       subBc[2000] = "world!"
       
       #add the sub-BaseContainer to the document Base Container
       bc.SetContainer(MyUniqueId, subBc)
    
       #set the Document Data using the plugin ID
       doc.SetDocumentData(PLUGIN_ID, bc)
       c4d.EventAdd()
    
       #get the sub containers data
       print bc[PLUGIN_ID][2000]
       
    if __name__=='__main__':
       main()
    


  • Hi,

    your second example is correct. Implementing your own data type that can be serialized with a BaseContainer, is a feature, that is only available in C++. But with stacking BaseContainers you can do alot.

    Cheers
    zipit



  • @zipit

    Hi! I updated my code example with line-by-line comments.

    It doesn't seem to be working as I can't close the file, then read back the SubContainer's data with this:

       #get the sub containers data
       print bc[PLUGIN_ID][2000]
    


  • Hi,

    for cid, value in doc.GetDocumentData(MyUniqueId):
          print cid, value
    

    and

    doc.SetDocumentData(MyUniqueId, subBc)
    

    instead of

    bc.SetContainer(MyUniqueId, subBc)
    

    i.e.: Your misconception is that you can get/set all document data in one container. You can't (with this method). You only write/read one settings container at a time. In this case the container you did register.

    Cheers
    zipit



  • @zipit Thank you so much for your patience. I changed what you said and

    doc.GetDocumentData(MyUniqueId)
    

    does print a BaseContainer, but this doesn't print anything:

    for cid, value in doc.GetDocumentData(MyUniqueId):
          print cid, value
    

    Updated script:

    import c4d
    
    PLUGIN_ID = 1234567
    MyUniqueId = 1000001
    
    def main():
        doc = c4d.documents.GetActiveDocument()
        #get the document's BaseContainer
        bc = doc.GetDataInstance()
        
        #create a sub-BaseContainer
        subBc = c4d.BaseContainer()
        subBc[1000] = "hello"
        subBc[2000] = "world!"
        
        #add the sub-BaseContainer to the document Base Container
        doc.SetDocumentData(MyUniqueId, subBc)
        
        #set the Document Data using the plugin ID
        doc.SetDocumentData(PLUGIN_ID, bc)
        c4d.EventAdd()
        
        print doc.GetDocumentData(MyUniqueId)
        # <c4d.BaseContainer object at 0x0000018F956DC1B0>
    
        #get the sub container's data
        for cid, value in doc.GetDocumentData(MyUniqueId):
            print cid, value
           
    if __name__=='__main__':
       main()
    


  • I'm confused in this example how the SubBaseContainer is being added to the BaseContainer. It seems like they're both being added to the Document.

    I might be mistaken, but this was how I envisioned the data structure:

    Document ⮧
       BaseContainer Data (ID = PLUGIN_ID) ⮧
          SubBaseContainer Data (ID = MyUniqueId)
    


  • Hi,

    as I said, you can't set the whole container. Or in other words you don't need the variable bc in your example. Here is one one example that shows you how to store hierarchical data and then retrieve it. I wrote this on my iPad, so there might be bugs/typos, but the concept should be clear.

    # Your settings container
    bc = c4d.BaseContainer()
    # One level of your container, we treat this like a list/folder
    folder = c4d.BaseContainer()
    # One item in your folder
    recipe_1 = c4d.BaseContainer()
    # Another item in your folder
    recipe_2 = c4d.BaseContainer()
    
    bc[ID_TITLE] = 'My Cooking recipes'
    bc[ID_DATA] = folder
    folder[1000] = recipe_1
    folder[1001] = recipe_2
    
    recipe_1[ID_TITLE] = 'Choclate delight'
    recipe_1[ID_INSTRUCTIONS] = 'Lorem Ipsum ...'
    recipe_2[ID_TITLE] = 'Cheesekake'
    recipe_2[ID_INSTRUCTIONS] = 'Lorem Ipsum ...'
      
    doc.SetDocumentData(ID_MY_SECRET_COOKING_RECIPES, bc)
    
    def print_container(bc):
        '''
        '''
        for cid, value in bc:
            print cid, value
            if isinstance(value, c4d.BaseContainer):
                print_container(value)
    
    print_container(doc.GetDocumentData(ID_MY_SECRET_COOKING_RECIPES))
    


  • @blastframe said in Writing data to the .c4d file:

    I'm confused in this example how the SubBaseContainer is being added to the BaseContainer. It seems like they're both being added to the Document.

    I might be mistaken, but this was how I envisioned the data structure:

    Document ⮧
       BaseContainer Data (ID = PLUGIN_ID) ⮧
          SubBaseContainer Data (ID = MyUniqueId)
    

    Hi,

    no, it is

    Document
    --- Stuff
    --- Other Stuff
    --- Your ID stuff
    --- Some clown is saving his cooking recipes here
    

    Cheers
    zipit



  • @zipit Thanks for the explanation of the data structure (and the code for clarity).

    I tried my best to get it working, but it's still not printing the data. I'm not sure if it was intentional, but I changed the line

    print_container(doc.SetDocumentData(ID_MY_SECRET_COOKING_RECIPES))
    

    as it was throwing an error for not passing a BaseContainer. Did you mean?

    print_container(doc.GetDocumentData(ID_MY_SECRET_COOKING_RECIPES))
    

    Regardless it's the same issue where it does see the BaseContainer in the print function, but cannot iterate through it.

    import c4d
    
    ID_MY_SECRET_COOKING_RECIPES = 2999999
    ID_TITLE = 1008
    ID_DATA = 1009
    ID_INSTRUCTIONS = 1010
    
    def print_container(bc):
        for cid, value in bc:
            print cid, value
            if isinstance(value, c4d.BaseContainer):
                print_container(value)
    
    def main():
        doc = c4d.documents.GetActiveDocument()
    
        # Your settings container
        bc = c4d.BaseContainer()
        # One level of your container, we treat this like a list/folder
        folder = c4d.BaseContainer()
        # One item in your folder
        recipe_1 = c4d.BaseContainer()
        # Another item in your folder
        recipe_2 = c4d.BaseContainer()
        
        bc[ID_TITLE] = 'My Cooking recipes'
        bc[ID_DATA] = folder
        folder[1000] = recipe_1
        folder[1001] = recipe_2
        
        recipe_1[ID_TITLE] = 'Choclate delight'
        recipe_1[ID_INSTRUCTIONS] = 'Lorem Ipsum ...'
        recipe_2[ID_TITLE] = 'Cheesekake'
        recipe_2[ID_INSTRUCTIONS] = 'Lorem Ipsum ...'
          
        doc.SetDocumentData(ID_MY_SECRET_COOKING_RECIPES, bc)
    
        print_container(doc.GetDocumentData(ID_MY_SECRET_COOKING_RECIPES))
    
    if __name__=='__main__':
       main()
    


  • Not sure if this matters, but my ultimate goal would be to save JSON data in the BaseContainer.



  • Hello,

    The function SetDocumentData can only be used to update the document settings.

    It does accept an Int as a "type" but if you put something else than DOCUMENTSETTINGS_GENERAL DOCUMENTSETTINGS_MODELING DOCUMENTSETTINGS_DOCUMENT DOCUMENTSETTINGS_ANIMATIONSYSTEM the function will simply do nothing. (and the last one is marked as private)

    BaseContainer is a tree system, you can see sub-BaseContainer just like a child object in the object manager.
    So you can have (infinite ?) BaseContainer inside BaseContainer.

    If you want to store json data, it's up to you. You can store all elements of your json data or simply store a string.

    import c4d
    
    PLUGIN_ID = 1234567
    MyUniqueId = 456789
    
    def main():
        #retrieves the document baseContainer
        docBC = doc.GetDataInstance()
    
        #create a sub-BaseContainer
        subBc = c4d.BaseContainer()
        subBc[1000] = "hello"
        subBc[2000] = "world!"
    
        # Add the container to the "main" Container
        docBC.SetContainer(MyUniqueId, subBc)
    
        # Updates the document container
        doc.SetData(docBC)
    
        # Print the values stored in our container.
        for cid, value in doc.GetDataInstance().GetContainer(MyUniqueId):
            print cid, value
        
        # Print Hello World
        print doc[MyUniqueId][1000], doc[MyUniqueId][2000]
    
    
    if __name__=='__main__':
       main()
    

    Cheers,
    Manuel



  • @m_magalhaes Hi Manuel and thank you for this contribution. This code's data, however, is not persisting when I do the following:

    • run the script to set the data
    • close and reopen the document.
    • comment out the lines setting the data (lines 11-19)
    • run the script to print the data

    Instead I get this error for doc[MyUniqueId]:

    TypeError: 'NoneType' object has no attribute '__getitem__'
    

    Also, is MyUniqueId supposed to be the PLUGIN_ID? Why is that not being used?

    Thanks!


Log in to reply