Adding ports to nodes.

ll2pakll

I apologize for re-creating the post, I forgot to include my system details:
Windows 10
Cinema 4d 2023.2.1

Hi, I'm trying to figure out node creation via script manager and have run into a place I can't get past on my own. I want to create an output port with global data for a node, but I don't understand how to do it. In one of the parameters "GvNode.AddPort(self, io, id, flag=GV_PORT_FLAG_IS_VISIBLE, message=False)" I need to enter id, but I don't understand where I can see the id I need. Please tell me how to add ports to nodes correctly, and if possible, tell me how to connect them. Thank you very much. Here is my code:

import c4d

cube1 = c4d.BaseObject(c4d.Ocube)
cube1.SetName('Куб 1')
cube2 = c4d.BaseObject(c4d.Ocube)
cube2.SetName('Куб 2')

doc.InsertObject(cube1)
doc.InsertObject(cube2)

xpresso = c4d.modules.graphview.XPressoTag()

cube1.InsertTag(xpresso)

NodeMaster = xpresso.GetNodeMaster()

node_1 = NodeMaster.CreateNode(NodeMaster.GetRoot(), c4d.ID_OPERATOR_OBJECT)
node_2 = NodeMaster.CreateNode(NodeMaster.GetRoot(), c4d.ID_OPERATOR_OBJECT, x=100)


node_1.AddPort(c4d.GV_PORT_OUTPUT, 1, c4d.GV_PORT_FLAG_IS_VISIBLE)

node_2.OperatorSetData(c4d.GV_ATOM, cube2, c4d.GV_OP_DROP_IN_BODY)

c4d.EventAdd()

ferdinand

Hello @ll2pakll ,

Welcome to the Plugin Café forum and the Cinema 4D development community, it is great to have you with us!

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About your First Question

Please avoid deleting posts in the future. You got things almost right, but seem to struggle a bit with the concept of DescID. Find my answer below.

I would also recommend having a look at these resources:

Cheers,
Ferdinand

Result:

Code:

"""Demonstrates how to create a port on a graph node and how to connect two nodes.

See [1] for an overview of the graphview module and [2] for details on DescID.

References:
    [1] https://github.com/PluginCafe/cinema4d_py_sdk_extended/tree/master/scripts/05_modules/xpresso
    [2] https://developers.maxon.net/forum/topic/13517/how-to-add-a-userdata-child-to-a-group-via-script
"""

import c4d

from c4d.modules import graphview as gv

doc: c4d.documents.BaseDocument

def main():
    """
    """
    # Create and name the two objects.
    cubeA: c4d.BaseObject = c4d.BaseObject(c4d.Ocube)
    cubeB: c4d.BaseObject = c4d.BaseObject(c4d.Ocube)
    
    doc.InsertObject(cubeA)
    doc.InsertObject(cubeB)
    cubeA.SetName("A")
    cubeB.SetName("B")

    # Create the tag, get the node master and the root of the Xpresso graph.
    tag: c4d.BaseTag = cubeA.MakeTag(c4d.Texpresso)
    master: gv.GvNodeMaster = tag.GetNodeMaster()
    root: gv.GvNode = master.GetRoot()

    # You said that you want to "create an output port with global data for a node". That is very
    # ambivalent or not possible. You cannot create a port for arbitrary data on a GvNode. You can
    # only create ports for the parameters a node holds. In the case of an object node also the
    # parameters of the scene element it wraps. The parameters are referenced via DescIDs and in
    # case of creating ports we must be quite precise. See [2] for details on the subject.
    
    # The parameter ID for the editor visibility of an object. We will use it both for the in and
    # output port, because they both target the same parameter.
    did: c4d.DescID = c4d.DescID(
        c4d.DescLevel(c4d.ID_BASEOBJECT_VISIBILITY_EDITOR, # ID of the element.
                      c4d.DTYPE_LONG,                      # Its data type, an integer.
                      0))                                  # The creator, the correct value would be
                                                           # Ocube or cubeA.GetType(), but 0, i.e.,
                                                           # undefined also works here.

    # Create the two nodes and set the referenced objects. When setting the references we do not
    # have to be as precise as when defining ports with our IDs.
    nodeA: gv.GvNode = master.CreateNode(root, c4d.ID_OPERATOR_OBJECT)
    nodeB: gv.GvNode = master.CreateNode(root, c4d.ID_OPERATOR_OBJECT, x=200)
    nodeA[c4d.GV_OBJECT_OBJECT_ID] = cubeA
    nodeB[c4d.GV_OBJECT_OBJECT_ID] = cubeB

    # Add an input and output port.
    outPort: gv.GvPort = nodeA.AddPort(c4d.GV_PORT_OUTPUT, did, c4d.GV_PORT_FLAG_IS_VISIBLE)
    inPort: gv.GvPort = nodeB.AddPort(c4d.GV_PORT_INPUT, did, c4d.GV_PORT_FLAG_IS_VISIBLE)
    
    # And connect them.
    outPort.Connect(inPort)

    c4d.EventAdd()

if __name__ == "__main__":
    main()

ll2pakll

@ferdinand said in Adding ports to nodes.:

DescID

Thank you so much. I am pleasantly surprised at the level of your responsiveness. When I wrote "Global Data" I accidentally used the wrong word, I meant "Global Coordinates". I have read your links and code very carefully. Actually the concept of DescID is not so much complicated as confusing, the easiest thing would be to have something like an interactive online converter that could show the attributes of the desired objects and their corresponding id. I will try to understand the concept of DescID, deeper. And thank you again for your very detailed answer. Have a nice day.