I have a tag plugin where I move tags from one object to another.
I tried several Undo types, but I cannot get it working.
What to do?

            childTags = child.GetTags()
            ....
            for childTag in childTags:
                #doc.AddUndo(c4d.UNDOTYPE_CHANGE, object)
                doc.AddUndo(c4d.UNDOTYPE_HIERARCHY_PSR, object)
                object.InsertTag(childTag)
                #doc.AddUndo(c4d.UNDOTYPE_NEW, object)

I did some ore testing and now I guess it is a programming error.
So, I guess my assumption was wrong.

I have a tag plugin that changes the position of the children of the object where the tag is attached to.
This works ok in the viewport, but when rendering it does not work.
I assume that the tag is not 'executed' during rendering?

What should I do to make it working?

@pim said in Current State to Object of a Subdivision Surface:

SendModelingCommand

Oops, I see Subdivision Renderer setting and not Subdivision Editor setting is taken into account.

I want to convert a SDS with a Cube as a child, to one polygon object.
Thus I select the SDS and do a "Current State to Object".

However, the resulting object does not seem to take the Subdivision Editor settings into account.

See below picture.
On top the SDS + Cube, below the result of the CSTO.

Using python gave me the same issue

    objList = c4d.utils.SendModelingCommand(
        command = c4d.MCOMMAND_CURRENTSTATETOOBJECT,
        list = [op],              # op.GetClone() did not help
        mode = c4d.MODELINGCOMMANDMODE_ALL,
        doc = doc,
        )       

    doc.InsertObject(objList[0])
    c4d.EventAdd()

And AliasTrans did not seem to help.

    trans = c4d.AliasTrans()
    if not trans or not trans.Init(doc):
        return False
    opClone = op.GetClone(c4d.COPYFLAGS_NONE, trans)
    trans.Translate(True)
                          
    objList = c4d.utils.SendModelingCommand(
        command = c4d.MCOMMAND_CURRENTSTATETOOBJECT,
        list = [opClone],
        mode = c4d.MODELINGCOMMANDMODE_ALL,
        doc = doc,
        )       

    doc.InsertObject(objList[0])
    c4d.EventAdd()

I am not sure how to / where to place Undo's when using a CSTO.
Should it be before (with an UNDOTYPE_CHANGE) or after (with an UNDOTYPE_NEW)?

        #doc.AddUndo(c4d.UNDOTYPE_CHANGE, poly)        
        objList = c4d.utils.SendModelingCommand(
            command = c4d.MCOMMAND_CURRENTSTATETOOBJECT,
            list = [poly],
            mode = c4d.MODELINGCOMMANDMODE_ALL,
            doc = doc,
            )       
        doc.AddUndo(c4d.UNDOTYPE_NEW, objList[0])

Thanks for the detailed answer.
And yes, I guess my approach is way to simple.
However, I use the normal of the polygon to place the plane and getting the minimal width and height, best fits a planar polygon.

"The point order is arbitrary. I'm not sure why you expect the points to start in a certain corner?"
For consistency I would expect the points to be in a predefined sequence.
Now it seems randomly (clockwise, anti clockwise, were is point a located?).

I want to fit images in selected polygons.
To do so, I get the polygon and then I like to get the smallest width and the smallest height of the polygon.
With this rectangle information, I create a plane and place one image on the plane.
The plane is then placed using the normal of the polygon.

Question: is there an easy way to get the smallest width and height of a polygon.

See for example this picture

Here how I calculate the width and height.

p = obj.GetPolygon(index)

a = allp[p.a]           
b = allp[p.b]
c = allp[p.c]
d = allp[p.d]

w1 = (a - d).GetLength()
w2 = (b - c).GetLength()
h1 = (a - b).GetLength()
h2 = (d - c).GetLength()

width = w1
if (w2 < w1): width = w2
height = h1
if (h2 < h1): height = h2

This code does not seem correct, because the Coordinate Manager show a different size.

Also, the sequence of the points (a,b,c,d) is not always the same.
Sometimes it starts in the lower left corner and sometime in the upper right corner.

How can I set / Get the Xref setting in the layerdata.

When doing layer_data = layer.GetLayerData(doc), I get:

{'solo': False, 'locked': False, 'render': False, 'color': Vector(0.189, 0.513, 0.789), 'manager': True, 'animation': False, 'generators': False, 'deformers': False, 'expressions': False, 'view': False}

Yes, I do the same.
I can check whether the obj is dirty and set the nbits again.

Thank you.