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!