Hello @Kantronin,

Thank you for reaching out to us. Your script does not work because it does not follow the conditions of MCOMMAND_JOIN.

Joins the objects that are parented to the passed null object. Passing multiple objects into SMC will not join them.

edit: Moved this into the correct forum and added a small example.

Cheers,
Ferdinand

Here is how I would write that in modern Cinema 4D. I have seen that your screenshot is from an older version such as S26, or even older, but I cannot write code examples for such old versions. There are multiple things that wont work in such old version such as type hinting and the mxutils lib, but you will be able to copy the general approach - move everything under a null while preserving the transforms.

Code """Demonstrates how to join all objects in a document. """ import c4d import mxutils doc: c4d.documents.BaseDocument # The currently active document. op: c4d.BaseObject | None # The primary selected object in `doc`. Can be `None`. def main() -> None: """Called by Cinema 4D when the script is being executed. """ # There is no super good way to do this in the manner you implied, joining everything in a # document. I clone here the whole document, which is not the cheapest operation (but also # not as expensive as it may sound like). When we do not have to join everything, it is better # just to clone the things you want to join. En even better way could be to not clone anything # and instead use undos to revert the transform and hierarchy changes we have to make. temp: c4d.documents.BaseDocument = doc.GetClone(c4d.COPYFLAGS_NONE) firstObject: c4d.BaseObject | None = temp.GetFirstObject() if firstObject is None: c4d.gui.MessageDialog("No object selected.") return # Get all objects in the document, and move them under a null object. We must record and # restore their global matrices, when we deconstruct the scene and move it all under one null # object. allObjects: list[c4d.BaseObject] = list(mxutils.IterateTree(firstObject, True)) null: c4d.BaseObject = mxutils.CheckType(c4d.BaseObject(c4d.Onull)) for obj in allObjects: mg: c4d.Matrix = obj.GetMg() # save the transform of the object obj.Remove() # Technically not necessary in the Python API, as it will do it for you when # you call things like InsertUnderLast. But C++ will not do that and a node # cannot be inserted more than once in a document, otherwise the fireworks # will start. obj.InsertUnderLast(null) obj.SetMg(mg) # restore the transform of the object under the null # Insert the null object into the temporary document and then join all objects under it. temp.InsertObject(null) result: list[c4d.BaseObject] = c4d.utils.SendModelingCommand( command=c4d.MCOMMAND_JOIN, list=[null], doc=temp, mode=c4d.MODELINGCOMMANDMODE_ALL, ) if not result: c4d.gui.MessageDialog("Failed to join objects.") return # Now insert the joined object into the original document. joinedObject: c4d.BaseObject = result[0] joinedObject.SetName("Joined Object") joinedObject.Remove() doc.InsertObject(joinedObject) c4d.EventAdd() if __name__ == '__main__': main()

Works! Thank you!

@ferdinand Thanks for detailed explanation.
Let me introduce the goals that the custom deformer plugin wants to achieve. (As can be seen from the cube, cube. 1, cube. 2... in the image, each object has a weight tag.) The custom deformer plugin needs to preprocess and store some data before the ModifyObjects () function works. (By clicking a button) Access the weight tag of each object to be deformed in Message (), preprocess and store some data, and then use the preprocessed data to execute the ModifyObjects () function to correctly process the deformation calculation.
9c418a15-9d3c-4466-83c2-0481e7b67c69-image.png

In C4D, it seems that the Surface deformer has achieved a similar function
5ef7303f-0ea2-4d3b-bed4-c342a755350c-image.png

(there are certain benefits to restricting the custom deformer plugin only to the parent level, as there is no need to spend effort on correctly linking the corresponding preprocessed data when the ModifyObjects () function works.But it did break the general logic operation of the deformer)

The only way you could do that is by checking each deformed object being passed into , to be the parent of the also passed in (i.e., the deformer also simply accessible via ). Only for an which is the parent of would you then carry out the modification.

Could you provide an snipped where you show how to cache it in a plugin?

Hi @Tpaxep,

Welcome to the Maxon developers forum and its community, it is great to have you with us!

Getting Started

Before creating your next postings, we would recommend making yourself accustomed with our forum and support procedures. You did not do anything wrong, we point all new users to these rules.

Forum Overview: Provides a broad overview of the fundamental structure and rules of this forum, such as the purpose of the different sub-forums or the fact that we will ban users who engage in hate speech or harassment. Support Procedures: Provides a more in detail overview of how we provide technical support for APIs here. This topic will tell you how to ask good questions and limits of our technical support. Forum Features: Provides an overview of the technical features of this forum, such as Markdown markup or file uploads.

It is strongly recommended to read the first two topics carefully, especially the section Support Procedures: How to Ask Questions.

About your First Question

The tool has indeed been updated, but the docs were not.

Here is how to call it. Note that you have to pass a polygon index, this is mandatory and it needs to be adjacent to one of the vertex to indicate a direction of the ring selection. Here is your script adapted, to be run on a sphere that was made editable.

import c4d from c4d import utils def select_ring_edge(obj, v1Id, v2Id, polyId): bc = c4d.BaseContainer() bc.SetData(c4d.MDATA_RING_SEL_STOP_AT_SELECTIONS, False) bc.SetData(c4d.MDATA_RING_SEL_STOP_AT_NON_QUADS, False) bc.SetData(c4d.MDATA_RING_SEL_STOP_AT_POLES, True) bc.SetData(c4d.MDATA_RING_BOTH_SIDES, False) bc.SetData(c4d.MDATA_RING_SWAP_SIDES, False) bc.SetData(c4d.MDATA_RING_FIRST_VERTEX, v1Id) bc.SetData(c4d.MDATA_RING_SECOND_VERTEX, v2Id) bc.SetData(c4d.MDATA_RING_POLYGON_INDEX, polyId) 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_NONE ) c4d.EventAdd() return result def main(): doc = c4d.documents.GetActiveDocument() obj = doc.GetActiveObject() if obj is None: c4d.gui.MessageDialog("select obj.") return firstVertex = 346 secondVertex = 347 polygonIndex = 312 result = select_ring_edge(obj, firstVertex, secondVertex, polygonIndex) if result: print("DONE") else: print("ERROR") if __name__ == '__main__': main()

Note that the same settings also apply for the ID_MODELING_LOOP_TOOL, just modify RING by LOOP in the constant so MDATA_RING_SEL_STOP_AT_SELECTIONS become MDATA_LOOP_SEL_STOP_AT_SELECTIONS.

Cheers,
Maxime.

Ok? will do

Hi @wen I've moved your topic to the bug section since it's indeed a bug, I will ping you on this topic once the fix is available, it should come in one of the next update.
The issue is that the internal cache is not properly updated and therefor this is failing.

With that's said there is a ugly workaround which consist of calling it twice so the cache is properly updated.
Find bellow a version that is going to work in all versions

import c4d import maxon import os def CreateRepFromUrl(url: maxon.Url) -> maxon.UpdatableAssetRepositoryRef: """Create a new repository from a given database URL. If there is no valid database at the given URL, it creates a database at the URL. It always create a new repository and the associated database asset, even if there are existing repositories for that database. """ # Make type checks if not isinstance(url, maxon.Url): raise TypeError("First argument is not a maxon.Url") # Create a unique identifier for the repository. rid = maxon.AssetInterface.MakeUuid(str(url), True) # Repositories can be composed out of other repositories which are called bases. In this # case no bases are used to construct the repository. But with bases a repository for all # user databases could be constructed for example. bases = maxon.BaseArray(maxon.AssetRepositoryRef) # Create a writable and persistent repository for the database URL. If #_dbUrl would point # to a location where no database has been yet stored, the necessary data would be created. if c4d.GetC4DVersion() < 2025200: try: repository = maxon.AssetInterface.CreateRepositoryFromUrl( rid, maxon.AssetRepositoryTypes.AssetDatabase(), bases, url, True, False, False, None) except Exception as e: repository = maxon.AssetInterface.CreateRepositoryFromUrl( rid, maxon.AssetRepositoryTypes.AssetDatabase(), bases, url, True, False, False, None) else: try: repository = maxon.AssetInterface.CreateRepositoryFromUrl( rid, maxon.AssetRepositoryTypes.AssetDatabase(), bases, url, True, False, False) except Exception as e: repository = maxon.AssetInterface.CreateRepositoryFromUrl( rid, maxon.AssetRepositoryTypes.AssetDatabase(), bases, url, True, False, False) if not repository: raise RuntimeError("Repository construction failed.") return repository if __name__ == '__main__': if not maxon.AssetDataBasesInterface.WaitForDatabaseLoading(): raise RuntimeError("Could not load asset databases.") dbPath = os.path.join(os.path.dirname(os.path.abspath(__file__)), "testdb") print(CreateRepFromUrl(maxon.Url(dbPath)))

Cheers,
Maxime.

@ferdinand Got it. Thanks you for the tips. Much appreciated

Hello @popandchop,

Welcome to the Maxon developers forum and its community, it is great to have you with us!

Getting Started

Before creating your next postings, we would recommend making yourself accustomed with our forum and support procedures. You did not do anything wrong, we point all new users to these rules.

Forum Overview: Provides a broad overview of the fundamental structure and rules of this forum, such as the purpose of the different sub-forums or the fact that we will ban users who engage in hate speech or harassment. Support Procedures: Provides a more in detail overview of how we provide technical support for APIs here. This topic will tell you how to ask good questions and limits of our technical support. Forum Features: Provides an overview of the technical features of this forum, such as Markdown markup or file uploads.

It is strongly recommended to read the first two topics carefully, especially the section Support Procedures: How to Ask Questions.

About your First Question

The question is impossible to answer in this form, we would need something concrete (a plugin and a scene which crashes for you) or a time stamp of a submitted crash report.

What you do there is this code snippet looks a bit unusual. I assume from the screen shot that you are inside a GeDialog, the code looks a bit like this could be GeDialog.Command or Message. Please read the Threading Manual, invoking an event, e.g., a command, is forbidden off-main thread. But in a dialog you are usually on the main thread (but you should still check with c4d,.threading.GeIsMainThread()). What is also rather odd, is what you call there:

if id == BTN_SceneRenderPictureViewer: self.Close() # This will shut down the dialog, think of it as a return statement. c4d.StopAllThreads() # This is generally the biggest nuke you can drop on Cinema 4D and should # be avoided. But in this context (a dialog that has been closed) this # seems extra dangerous. Why are you doing this? time.sleep(0.1) # This makes things even worse, as it increases the chance that the dialog # has been destroyed before the last line of this function has been # executed. If I had to guess, this is probably crashing here. c4d.CallCommand(12099)

I assume you hve a modal dialog and that you run into issues with opening the picture viewer due to that? Either make your dialog non-modal (in GeDialog.Open) and then first send the command and then close the dialog or keep using a modal dialog and detach the code from the instance of the dialog.

import c4d class MyModalDialog (c4d.gui.GeDialog): BTN_SceneRenderPictureViewer: int = 1000 # ... def Command(self, cid: int, msg: c4d.BaseContainer) -> bool: if cid == MyModalDialog.BTN_SceneRenderPictureViewer: MyModalDialog.CloseAndAction(self, 12099) return True @staticmethod def CloseAndAction(dlg: "MyModalDialog", cid: int) -> None: """Closes the passed dialog and executes a command. Args: dlg (MyModalDialog): The dialog instance to close. cid (int): The command ID to execute after closing the dialog. """ if not dlg or not c4d.threading.GeIsMainThread(): return dlg.Close() c4d.CallCommand(cid) if __name__ == '__main__': dlg = MyModalDialog() dlg.Open(c4d.DLG_TYPE_MODAL, defaultw=400, defaulth=300, title="My Modal Dialog")

Cheers,
Ferdinand

Hello @Amazing_iKe,

Welcome to the Maxon developers forum and its community, it is great to have you with us!

Getting Started

Before creating your next postings, we would recommend making yourself accustomed with our forum and support procedures. You did not do anything wrong, we point all new users to these rules.

Forum Overview: Provides a broad overview of the fundamental structure and rules of this forum, such as the purpose of the different sub-forums or the fact that we will ban users who engage in hate speech or harassment. Support Procedures: Provides a more in detail overview of how we provide technical support for APIs here. This topic will tell you how to ask good questions and limits of our technical support. Forum Features: Provides an overview of the technical features of this forum, such as Markdown markup or file uploads.

It is strongly recommended to read the first two topics carefully, especially the section Support Procedures: How to Ask Questions.

About your First Question

@Dunhou is right, this, querying for values is not possible with graph descriptions at the moment (querying for nodes is possible to some extent) . What you could do, is use a graph query to select some node over its properties, and then just write its ID. ApplyDescription returns the true nodes of a graph sorted over their IDs. Then you could grab that node you are interested in, get the port you want, and write the value based on the existing value. Or you could let graph descriptions be graph descriptions and just use the low level API directly. You can have a look at the Nodes API examples for some inspiration how this lower level API works.

On of the things I am working on at the moment, is extending the query ability of graph descriptions. What I have implemented so far, is nested queries (you can select nodes over them being connected in a specific way), more query operators (<, >, !=, regex, etc.), and something I dubbed query compositions that allows you to query one node property for more than one value, so that can do stuff like checking if something is smaller than 1, AND bigger than 0, AND not exactly 0.5, or that something matches the regex "$foo." OR "$bar.". What has been also added so far, is a new function called EvaluateQuery which allows you to run queries without having to apply a description. But this function also operates on the level that it will return nodes, and not ports or even values.

I of course also have thought about this, querying for values directly, but I have not implemented it for now, as you can do it somewhat easily yourself with EvaluateQuery (and to some extent even with ApplyDescription) by just getting the port and then its value. But I understand the alure, maybe when I have time, I will fit in a EvaluateValueQuery. The update was planned for one of later 2025.X releases, but at the moment it looks more like that it will be 2026.0.0.

When you need help with the lower level Nodes API, just open a posting here on the forum with what you got.

Cheers,
Ferdinand

@ferdinand Got it, thanks for the heads-up!

FYI: This has been fixed and will be shipped in a future version of Cinema 4D.

Hey @itstanthony,

sorry for the delay. So, here is how you could do this. It is not the pretiest solution, but the only that works at the moment for graph descriptions. You could of course also use the full Nodes API to do this.

I hope this helps and cheers,
Ferdinand

import c4d import maxon import mxutils doc: c4d.documents.BaseDocument # The active Cinema 4D document. def CreateMaterials(count: int) -> None: """Creates #count materials with relevant "Store Color To AOV" setup. """ mxutils.CheckType(count, int) for i in range(count): graph: maxon.NodesGraphModelRef = maxon.GraphDescription.GetGraph( name=f"AovSetup.{i}", nodeSpaceId=maxon.NodeSpaceIdentifiers.RedshiftMaterial) maxon.GraphDescription.ApplyDescription(graph, [ { "$type": "Color", "Basic/Name": "Base Color", "Inputs/Color": maxon.Vector(1, 1, 1), "$id": "base_color" }, { "$type": "Color", "Basic/Name": "Metallic", "Inputs/Color": maxon.Vector(0.0, 0.0, 0.0), "$id": "metallic_color" }, { "$type": "Color", "Basic/Name": "Roughness", "Inputs/Color": maxon.Vector(0.5, 0.5, 0.5), "$id": "roughness_color" }, { "$type": "Color", "Basic/Name": "Normal", "Inputs/Color": maxon.Vector(0.5, 0.5, 1), "$id": "normal_color" }, { "$type": "Color", "Basic/Name": "AO", "Inputs/Color": maxon.Vector(1, 1, 1), "$id": "ao_color" }, { "$type": "Color", "Basic/Name": "Emissive", "Inputs/Color": maxon.Vector(0, 0, 0), "$id": "emissive_color" }, { "$type": "Output", "Surface": { "$type": "Store Color To AOV", "AOV Input 0": "#base_color", "AOV Name 0": "BaseColor", "AOV Input 1": "#metallic_color", "AOV Name 1": "Metallic", "AOV Input 2": "#roughness_color", "AOV Name 2": "Roughness", "AOV Input 3": "#normal_color", "AOV Name 3": "Normal", "AOV Input 4": "#ao_color", "AOV Name 4": "AO", "AOV Input 5": "#emissive_color", "AOV Name 5": "Emissive", "Beauty Input": { "$type": "Standard Material", "Base/Color": "#base_color", "Base/Metalness": "#metallic_color", "Reflection/Roughness": "#roughness_color", "Geometry/Bump Map": "#normal_color", "Geometry/Overall Tint": "#ao_color", "Emission/Color": "#emissive_color", } } } ] ) def ModifyMaterials() -> None: """Modifies all materials in the scene, with the goal of removing the "Store Color To AOV" node in material setups as created above. """ for graph in maxon.GraphDescription.GetMaterialGraphs(doc, maxon.NodeSpaceIdentifiers.RedshiftMaterial): try: # Remove a "Store Color To AOV" node from the graph that matches the given AOV names. nodes: dict[maxon.Id, maxon.GraphNode] = maxon.GraphDescription.ApplyDescription(graph, { "$query": { # Match the fist node of type "Store Color To AOV" ... "$qmode": maxon.GraphDescription.QUERY_FLAGS.MATCH_FIRST, "$type": "Store Color To AOV", # ... that has the following AOV names. Graph queries currently do not yet # support nested queries, i.e., query to which nodes a node is connected to. # This will come with the next major version of Cinema 4D/the SDK. "AOV Name 0": "BaseColor", "AOV Name 1": "Metallic", "AOV Name 2": "Roughness", "AOV Name 3": "Normal", "AOV Name 4": "AO", "AOV Name 5": "Emissive", }, "$commands": "$cmd_remove" } ) # At this point we have to cheat a little bit, as the query abilities of graph # descriptions are not yet up to the task of what we would have to do here, as we # would have to query for a node by its type and at the same time set its ID, which is # not possible yet (I will also add this in a future version, but I am not yet sure when). # So what we do, is exploit the fact that #GraphDescription.ApplyDescription() will turn # dictionary/map of id:node relations and we can predict how a Redshift Output and # Standard Material will start (with "output@" and "standardmaterial@"). outputNodeId: str | None = next( str(key) for key in nodes if str(key).startswith("output@")) standardMaterialNodeId: str | None = next( str(key) for key in nodes if str(key).startswith("standardmaterial@")) if not outputNodeId or not standardMaterialNodeId: raise ValueError("Could not find Output or Standard Material node in the graph.") # Now that we have this information, we could either use the traditional Nodes API to # wire these two nodes together, or we can use the GraphDescription API to do this. # Connect the existing Output node to the existing Standard Material node. maxon.GraphDescription.ApplyDescription(graph, { "$query": { "$qmode": maxon.GraphDescription.QUERY_FLAGS.MATCH_FIRST, "$id": outputNodeId, }, "Surface": f"#{standardMaterialNodeId}" } ) except Exception as e: print(e) continue # Some concluding thoughts: This task, although it might look trivial, has actually some # complexities. The main issue is that while we have the quasi-guarantee that there will # only be one Output (i.e., 'end node') in a Redshift material graph, we cannot # guarantee that there will only be one Standard Material node in the graph. # # To truly solve all this, we would need the 2026.0.0 graph query capabilities, so that we # can more precisely select which nodes we mean. # # What occurred to me while writing this, is that it would also be very nice to have a # command like "$cmd_remove_smart" which attempts to remove a node while maintaining the # connection flow, in your case wire the Standard Material node to the Output node. # # In general, this an unsolvable riddle, but many node relations in a material graph are # trivial, i.e., there is only one ingoing and one outgoing connection, so that it would # be easy to try to connect these two nodes together. In your case, deleting the # "Store Color To AOV" node, this would however never be possible as we have here seven # color inputs and one color output. From an abstract API perspective, it is impossible to # determine which one of the seven inputs should be connected to the output, as we do not # have the higher human insight to determine that the Standard Material node is the relevant # node to connect to the Output node. if __name__ == '__main__': CreateMaterials(5) # Create five materials with the "Store Color To AOV" setup. ModifyMaterials() # Remove the "Store Color To AOV" node from all materials. c4d.EventAdd() # Refresh Cinema 4D to show changes

@ferdinand Thansk!

@ferdinand Thank you for explanation. The point of confusion should be marked as 2 in the image. in doc the counterclockwise rotation (ccw) refers to the counterclockwise rotation from the spatial perspective of the image. but for the same rotation, the z-axis should have rotated clockwise（cw）. However, in any case, the calculation is correct, only the description is different。
(Describing a rotation of an axis, it is assumed that a person looks in the negative direction from the positive direction of the axis, and based on this, counterclockwise and clockwise are defined)

@ferdinand
Thank you for the detailed explanation and the solution! This perfectly solved my problem, and I really appreciate you clarifying how to access the DESC_CYCLE values！！

We will very likely never abandon this technique. The issue is more that there are a lot of hacks in the Spline Mask code and almost none of them are shown in the public code example. And we cannot publish all of these hacks both for strategic (we do not want to show all of our internals) and practical reasons (we cannot explain all the nitty gritty details there).

It was not such a good decision to publish that code example; which as far as I understood came to pass as a user asked as to how the Spline Mask object has been realized. But we probably should just have said "no" then. Just as much as I probably should not have shown you that simulation hack. Hacks lead to more hacks and more problems.

Cheers,
Ferdinand

PS: And to be super verbose, you ONLY need this pattern when you "have to" implement a spline that has other (spline) objects as inputs. When you have implemented regular splines like this, you should probably revert that.

Good to hear!