Here's my prototype, if you are interested in my goal

Right now, everything works as expected, but only with these lines of code.

profile = GetCloneSpline(profile_orig)
path = GetCloneSpline(path_orig)

I'm happy with the current result. So, I'd love to get some additional advice on correctness and optimization. I think your previous answer was comprehensive enough, so I'll try to integrate some of it.
But I'd also be very grateful if you could take a look at my plugin and perhaps give me some more specific optimization tips. If that's not too much trouble, of course!

@ferdinand @ThomasB
Anyway, thanks for your replies and advices!

Thanks for the answers! The method works great, but I ran into a problem when running the code further. My next part looks like this

        spline = path.GetRealSpline()
        profile_spline = profile.GetRealSpline()
        if spline is None or profile_spline is None:
            return None

        points_profile = profile_spline.GetAllPoints()
        count_profile = len(points_profile)
        is_profile_closed = profile_spline.IsClosed()
        if count_profile < 2:
            return None

        sh = SplineHelp()
        if not sh.InitSplineWith(
            spline,
            c4d.SPLINEHELPFLAGS_GLOBALSPACE
            | c4d.SPLINEHELPFLAGS_USERDEFORMERS
            | c4d.SPLINEHELPFLAGS_CONTINUECURVE
        ):
            return None

With this approach, my path is no longer processed as GetRealSpline, while the profile is processed as expected.

I adjusted the code slightly, integrating the def GetCloneSpline function from this code.

Now I get this

        profile_orig = op.GetDown()
        if profile_orig is None:
            return None

        path_orig = profile_orig.GetNext()
        if path_orig is None:
            return None

        dirty = op.CheckCache(hh) or op.IsDirty(c4d.DIRTYFLAGS_ALL)

        profileData = op.GetAndCheckHierarchyClone(
            hh,
            profile_orig,
            c4d.HIERARCHYCLONEFLAGS_ASSPLINE,
            True)

        if not any([dirty, profileData["dirty"]]):
            return profileData["clone"]


        profile = GetCloneSpline(profile_orig)
        path = GetCloneSpline(path_orig)

Maybe I have missed something important (let me know), but overall everything works like i want. But I have a few questions

1. Now I'm using CSTO as a quick fix for the GetRealSpline issue, but it seems incorrect. I'd like to know which way was better:
   use CSTO outside of GVO (using a temporary document, as in the example) for improvement, or if I should try to find an alternative solution?

2. I didn't fully understand this message: is it better to use caches instead of cloning, or should I use both in combination?

Hi, forum!
I'm working on a tool the principle of operation of which is similar like a "Sweep". It wraps one "profile" spline around a "path" spline. I want any geometric change to these splines to trigger an update. I think I've figured it out using this code.

def GetVirtualObjects(self, op, hh):
   
    doc = op.GetDocument()
    path = op.GetDown()
    if path is None:
        return None

    profile = path.GetNext()
    if profile is None:
        return None

    dirty = op.CheckCache(hh)\
            or op.IsDirty(c4d.DIRTY_DATA)\
            or path.IsDirty(c4d.DIRTY_DATA)\
            or path.IsDirty(c4d.DIRTY_MATRIX)\
            or profile.IsDirty(c4d.DIRTY_DATA)\
            or profile.IsDirty(c4d.DIRTY_MATRIX)
    if not dirty: return op.GetCache(hh)


    path = c4d.utils.SendModelingCommand(
        c4d.MCOMMAND_CURRENTSTATETOOBJECT,
        [path],
        c4d.MODELINGCOMMANDMODE_ALL,
        c4d.BaseContainer(),
        doc
    )[0]

    profile = c4d.utils.SendModelingCommand(
        c4d.MCOMMAND_CURRENTSTATETOOBJECT,
        [profile],
        c4d.MODELINGCOMMANDMODE_ALL,
        c4d.BaseContainer(),
        doc
    )[0]

However, I'd like to hide the child elements, but I can't figure out how I can do it more correctly

I have try use c4d.BaseObject.Touch() and my child is hide, but I can't edit my path/profile dynamically. If I edit the path/profile, I need to refresh the viewport or op settings to see the changes.

I tried this code. Perhaps I didn't fully understand something and missed something.

path = op.GetDown()
if path is None:
    return None

profile = path.GetNext()
if profile is None:
    return None

path.Touch()
profile.Touch()

dirty = op.CheckCache(hh)\
    or op.IsDirty(c4d.DIRTY_DATA)\
    or path.IsDirty(c4d.DIRTY_DATA)\
    or path.IsDirty(c4d.DIRTY_MATRIX)\
    or profile.IsDirty(c4d.DIRTY_DATA)\
    or profile.IsDirty(c4d.DIRTY_MATRIX)
if not dirty: return op.GetCache(hh)

Besides this, I tried using op.GetAndCheckHierarchyClone like it was in this thread https://developers.maxon.net/forum/topic/10491/13941_hide-child-of-object-plugin/3

path = op.GetDown()
if path is None:
    return None

profile = path.GetNext()
if profile is None:
    return None

ProfileClone = op.GetAndCheckHierarchyClone(hh, profile, c4d.HIERARCHYCLONEFLAGS_ASSPLINE, False)

ProfileCloneDirty = ProfileClone["dirty"]
ProfileCloneClone = ProfileClone["clone"]

PathClone = op.GetAndCheckHierarchyClone(hh, path, c4d.HIERARCHYCLONEFLAGS_ASSPLINE, False)

PathCloneDirty = PathClone["dirty"]
PathCloneClone = PathClone["clone"]

if not ProfileCloneDirty:
    return ProfileCloneClone

if not PathCloneDirty:
    return PathCloneClone

path_upd = c4d.utils.SendModelingCommand(
    c4d.MCOMMAND_CURRENTSTATETOOBJECT,
    [PathCloneClone],
    c4d.MODELINGCOMMANDMODE_ALL,
    c4d.BaseContainer(),
    doc
)[0]

profile_upd = c4d.utils.SendModelingCommand(
    c4d.MCOMMAND_CURRENTSTATETOOBJECT,
    [ProfileCloneClone],
    c4d.MODELINGCOMMANDMODE_ALL,
    c4d.BaseContainer(),
    doc
)[0]

However, this reduces performance compared to the code above. I would be very grateful if you could help me figure out how I can do this more correctly and optimized.

P.s I think my question will seem primitive, but I'm just learning the API, so don't judge me too harshly

Hi folks, I am actively trying to learn Python for Cinema 4D, and lately I have been struggling with edge selection, specifically the Loop and Ring functions.
I got the code working as expected in r21, but in r25 and 2024 it no longer works, I have been trying to figure out what the problem is, but alas, I have not been able to. I would really appreciate it if you could show me what I am missing

import c4d
from c4d import utils

def select_ring_edge(obj, edge_id):
    bc = c4d.BaseContainer()
    bc.SetData(c4d.MDATA_RING_EDGE, edge_id)
    bc.SetData(c4d.MDATA_RING_SELECTION, c4d.SELECTION_NEW)

    result = c4d.utils.SendModelingCommand(
        command=c4d.ID_MODELING_RING_TOOL,
        list=[obj],
        mode=c4d.MODELINGCOMMANDMODE_EDGESELECTION,
        bc=bc,
        doc=c4d.documents.GetActiveDocument(),
        flags=c4d.MODELINGCOMMANDFLAGS_CREATEUNDO
    )
    c4d.EventAdd()
    return result

def main():
    doc = c4d.documents.GetActiveDocument()
    obj = doc.GetActiveObject()
    if obj is None:
        c4d.gui.MessageDialog("select obj.")
        return

    edge_index = 3

    result = select_ring_edge(obj, edge_index)
    if result:
        print("DONE")
    else:
        print("ERROR")

if __name__ == '__main__':
    main()