drag parameter to user data field like in console

  • On 28/03/2017 at 02:26, xxxxxxxx wrote:

    I'm trying to do something cheeky here, wondering if its possible.
    I want to make a python tag which performs an action on an object's parameters, but the user can define which parameter it is performed on by just dragging the parameter into a user data field;
    exactly like how we can drag a parameter or object into our python scripts or console.
    I thought I could do this with a string field but it doesn't let me, link field doesn't either.

    What makes the console input field so special, is there any way this could be done?

  • On 29/03/2017 at 05:23, xxxxxxxx wrote:


    The Console input is an edit text that processes the drag and drop events for parameters. Same for the Script Manager except it's a multi-line edit text.

    You can create a String user data that uses the Multi-Line String Interface in Python mode (Check PYTHON in Details tab). The Multi-Line String GUI accepts dragged parameters.

    Then in the Python tag you can evaluate a dynamically built expression string generated with the String user data that contains the parameter ID.
    Here's some code:

    import c4d
    def main() :
        obj = op.GetObject()
        data = obj[c4d.ID_USERDATA,1]
        # Evaluates the parameter ID string
        # Returns a list of integers for the description levels
        paramID = eval(data)
        print paramID
        # Builds the expression obj[ID]
        expr = "obj" + data
        paramValue = eval(expr)
        print paramValue

  • On 30/03/2017 at 11:39, xxxxxxxx wrote:

    Hey thank you that works great! 
    I can now get the value of the dragged in parameter.
    But, if you wanted to set the evaluated parameter, how would you proceed?

  • On 31/03/2017 at 07:25, xxxxxxxx wrote:

    Originally posted by xxxxxxxx

    But, if you wanted to  set  the evaluated parameter, how would you proceed?

    You can set the evaluated parameter with  obj ->SetParameter( id, data, flags ).
    SetParameter() needs a complete DescID (with the DescLevel dtype filled) to effectively set a parameter.
    To get a full DescID, the best solution is to use Description.CheckDescID() (function added in R18).

    Here's some code:

    import c4d
    def main() :
        obj = op.GetObject()
        data = obj[c4d.ID_USERDATA,1]
        param = eval(data)
        desc = obj.GetDescription(c4d.DESCFLAGS_DESC_0)
        if desc is None:
        partialID = c4d.DescID()
        for level in param:
        completeID = desc.CheckDescID(partialID, [obj])
        if completeID is None:
        obj.SetParameter(completeID, 100, c4d.DESCFLAGS_SET_0)

  • On 31/03/2017 at 11:19, xxxxxxxx wrote:

    This really exciting, it works perfectly.
    I don't quite grasp whats happening with all this ID stuff, I need to read up on it!
    Thanks again!

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