hi @m_adam, thanks a lot for your answer!
I spent two days trying to implement the function in my code, but no success again 
I think the problem now is more related to python than the C4D SDK,i'm not that experienced on it...
The error i'm getting is:
AttributeError: 'testplugin' object has no attribute 'hdrs'
hdrs is the list of strings (file paths), but seems that this list cannot be read by the GetDDescription function....
I've tried putting it as a global variable, also putting under testplugin class, under Execute, etc..
Tried putting the GetDDescription and SetDParameter as a inner function of Execute (I think this is wrong.. didn't give me errors, but updating the cycle doesn't work too haha).
Here's the structure of my plugin, I removed some irrelevant parts so we can focus better where the error is...
Do you think the structure is correct or am I missing something ?
the .res file is the same as in my first post.
import c4d
import os
import sys
from c4d import gui, plugins, bitmaps
PLUGIN_ID = 1000001
TESTSCALE = 1001
STRINGTEST = 1003
class testplugin(plugins.TagData):
def Init(self, node):
tag = node
data = tag.GetDataInstance()
FDWhite = c4d.Vector(1,1,1)
data.SetBool(FDENABLEBG, True)
data.SetInt32(FDSATURATION, 100)
data.SetVector(FDTINT, FDWhite)
data.SetInt32(FDSAMPLES, 64)
def Execute(self, tag, doc, op, bt, priority, flags):
datafilename = tag.GetDataInstance() #FD Folder path
path = datafilename.GetFilename(STRINGTEST)
extensions = ["exr","hdr"]
hdrs = []
if path != "":
files = os.listdir(path)
for names in files:
ext = names.rsplit(".",1)
if ext[1] in extensions:
hdrs.append(path+'\\'+names)
return c4d.EXECUTIONRESULT_OK
def GetDDescription(self, node, description, flags): # Called by C4D when loading description
data2 = node.GetDataInstance()
if data2 is None:
return False
if not description.LoadDescription(node.GetType()): # Load the description
return False
singleID = description.GetSingleDescID()
paramID = c4d.DescID(c4d.TESTSCALE)
if singleID is None or paramID.IsPartOf(singleID)[0]:
bcParam = description.GetParameterI(c4d.TESTSCALE)
items = c4d.BaseContainer()
for i, hdrs in enumerate(self.hdrs):
items.SetString(i, hdrs)
bcParam[c4d.DESC_CYCLE] = items
return (True, flags | c4d.DESCFLAGS_DESC_LOADED)
def SetDParameter(self, node, id, t_data, flags): # Called when a parameter is Set
if not node:
return
if id[0].id == c4d.STRINGTEST:
self.hdrs.append(t_data)
return (True, flags | c4d.DESCFLAGS_PARAM_SET)
return False
if __name__ == "__main__":
bmp = bitmaps.BaseBitmap()
dir, file = os.path.split(__file__)
bitmapfile = os.path.join(dir, "res", "icon.tif")
result = bmp.InitWith(bitmapfile)
plugins.RegisterTagPlugin(id=PLUGIN_ID, str="FD HDR", info=c4d.TAG_EXPRESSION|c4d.TAG_VISIBLE, g=testplugin, description="testplugin", icon=bmp)
thanks again 
