Accessing object properties



  • On 15/12/2017 at 13:17, xxxxxxxx wrote:

    Hi!

    I'm looking to write a simple script that goes through each frame and saves some data (position and rotation coordinates) from the selected object. However the documentation lists only methods, no properties and I can't figure out how to access the data.

    Dragging in the name of the coordinate field to the Python editor places something like this in the code: [c4d.ID_BASEOBJECT_POSITION,c4d.VECTOR_X], which is a list of 2 integers that don't seem to correlate to the value of the given coordinate.

    Help please, thank you,
    zoliking



  • On 17/12/2017 at 11:37, xxxxxxxx wrote:

    So after failing to find a tutorial I decided to find some example scripts and try to get somewhere from there. I managed to find the method doc.GetFirstObject(), which allowed access to the data I need. However I ran into a new problem: the instance it returns seems to contain the information about the object on the frame I start the script on, not the frame that the application is on during the call. Any ideas?

    def goToFrame(frameNumber) :
      fps = doc[c4d.DOCUMENT_FPS]
      time = c4d.BaseTime(frameNumber, fps)
      doc.SetTime(time)
      c4d.EventAdd()

    def main() :
      data = []
     
      for i in range(0,46) :
          goToFrame(i)
          selectedObject = doc.GetFirstObject()
          pos = selectedObject.GetAbsPos()
          rot = selectedObject.GetAbsRot()
         
          data.append(pos.x)
          data.append(pos.y)
          data.append(pos.z)
          data.append(rot.y)
          data.append(rot.x)
          data.append(rot.z)



  • On 18/12/2017 at 01:58, xxxxxxxx wrote:

    Hello,

    Objects in Cinema 4D store parameters. Such parameters are identified using a DescID object. A DescID object is made of various numbers and these numbers are typically defined using symbols. c4d.ID_BASEOBJECT_POSITION and c4d.VECTOR_X are such symbols. So you can use these symbols to access parameter values using GetParamter() :

      
    descid = c4d.DescID(c4d.DescLevel(c4d.ID_BASEOBJECT_POSITION, 0, 0), c4d.DescLevel(c4d.VECTOR_X, 0, 0))  
    xCoordiante = op.GetParameter(descid, c4d.DESCFLAGS_GET_0)  
    

    But there are shorter ways of writing the same thing using the subscript operator:

      
    xCoordiante = op[c4d.ID_BASEOBJECT_POSITION,c4d.VECTOR_X]  
    

    In the online documentation you find information on GetParameter() and DescID. You find various Python examples in the Python documentation download and on GitHub.

    Setting the time of a document will NOT animate the document. To animate the document you explicitly do that. This can be done using ExecutePasses().

    A similar topic was just discussed in this thread: "python plugin for every frame".

    You also find additional information in the C++ documentation on these topics: BaseDocument Manual.

    best wishes,
    Sebastian



  • On 18/12/2017 at 08:33, xxxxxxxx wrote:

    ExecutePasses() worked, thank you for that and all the other great information too! You are a life saver!


Log in to reply