Ah ! They are called Proxy Tags and I can see the actual tag with the MSG_GETREALTAGDATA ! Thank you ️

I managed to solve this and make the Python Effector look like a plugin. I programmatically add the object, its icon and the script to it. But because it's impossible to add the User Data, I added them manually and then saved the project file containing the Effector object. Then added a simple condition if the scene file is present in the plugin folder merge the object to the current scene, else add the object without the User Data.

I think this solution is acceptable and elegant to present something as a complete plugin and not as a C4D scene file (usually a demonstration file) as I have encounter so far.

Is it possible to create a Python Effector plugin or there's only the Python Effector binder for that ?
I can't find a pure Python Plugin Effector object example.
I don't know how to make my object be accepted as an Effector on MoGraph generators Effector lists.

These attributes :

#     MDATA_LOOP_FIRST_VERTEX           = 1130, // LONG
#     MDATA_LOOP_SECOND_VERTEX          = 1131, // LONG
#     MDATA_LOOP_POLYGON_INDEX          = 1132, // LONG

and many more aren't documented here https://developers.maxon.net/docs/py/2026_1_0/cinema_resource/tool/toolloopselection.html

Is this an intended omission or a neglect ? should I be visiting the C++ SDK more often ?

And how do I see the data type and call ID for each of them in the documentation ? I don't see them here https://developers.maxon.net/docs/cpp/2026_1_0/toolloopselection_8h.html
(I would upload a screenshot but I get a server error about not being able to parse the file)

How can I read data from Selection Tags created by SceneNodes modifiers like the Store Selection ?

Seems like they don't work like the other selection tags.

Thank you, this make more sense.
I was passing vertices not polygon indexes and was calling MDATA_LOOP_SELECTION_TYPE instead of MDATA_LOOP_SELECTION.

Hi community,
I wonder if there's a direct call for accessing Loop and Ring Selection results (element data) by providing an edge.
I tried the indirect method of actually using the interactive user tool on a temporary project but I constantly run in walls either by crashing C4D or just not getting any results back.

Is there a direct method that utilizes the native C4D Ring/Loop Selection geometry traversing algorithms with a direct input of 2 points or an edge ID ?
If not, is there a direct method from the C++ API ?
If explaining the concept of how to use the interactive tool programmatically in an algorithm is too complicated and there's not a similar example for it, can I at least know if the native C4D algorithm is UV-traversing or Geometry-traversing in order to implement one myself ?

I want to create a parametric generator similar to the SceneNodes Loop/Ring Selection Modifier that is more intuitive in use because the current implementation uses as inputs two point IDs. This isn't practical at all as the two points provided most of the time will not be related (belong to the same edge) at all returning nothing back. My implementation will be using an Edge ID counter to cycle the geometry and have just an Index user attribute using a pre-constructed table of all unique possible selections so the user can cycle all unique Ring and Loop selections. (Useful for effects, multiple selections, Field-driven selections etc)