Hey, yes it is. The trick is c4d.LV_CHECKBOX_HIDE, the relevant bits happen in GetDropDownMenu. Cheers, Ferdinand I removed the command, you can directly run this in the script manager: import c4d PLUGIN_ID = 12345678 PLUGIN_NAME = "ListView Dropdown Prototype" ID_TREE_VIEW = 1000 ID_FILE_NAME = 1001 ID_IMPORT_OPTION = 1002 ID_IMPORT_OPTION_DEFAULT = 1100 ID_IMPORT_OPTION_HIGH = 1101 ID_IMPORT_OPTION_MEDIUM = 1102 ID_IMPORT_OPTION_LOW = 1103 dummyfile_list = ["hud.stp", "material_reference.wrl", "front_axle.stp", "body.wrl", "wheel_variant.stp"] class DummyFile: def __init__(self, file_name, import_option="Default"): self.file_name = file_name self.import_option = import_option class DummyFileListView(c4d.gui.TreeViewFunctions): def __init__(self, dialog): self.dialog = dialog self.files = [DummyFile(file_name) for file_name in dummyfile_list] def GetFirst(self, root, userdata): return self.files[0] if self.files else None def GetNext(self, root, userdata, dummy_file): current_index = self.files.index(dummy_file) next_index = current_index + 1 return self.files[next_index] if next_index < len(self.files) else None def GetDown(self, root, userdata, dummy_file): return None def GetId(self, root, userdata, dummy_file): return id(dummy_file) def GetName(self, root, userdata, dummy_file): return dummy_file.file_name def IsSelected(self, root, userdata, dummy_file): return False def GetColumnWidth(self, root, userdata, dummy_file, column_id, area): if column_id == ID_FILE_NAME: return area.DrawGetTextWidth(dummy_file.file_name) + 24 if column_id == ID_IMPORT_OPTION: return 120 return 96 def GetDropDownMenu(self, root, userdata, dummy_file, column_id, menu_info): if column_id != ID_IMPORT_OPTION: menu_info["state"] = c4d.LV_CHECKBOX_HIDE return if not dummy_file.file_name.lower().endswith(".stp"): menu_info["state"] = c4d.LV_CHECKBOX_HIDE return options = { ID_IMPORT_OPTION_DEFAULT: "Default", ID_IMPORT_OPTION_HIGH: "High", ID_IMPORT_OPTION_MEDIUM: "Medium", ID_IMPORT_OPTION_LOW: "Low", } for option_id, label in options.items(): menu_info["menu"].SetString(option_id, label) menu_info["entry"] = next( option_id for option_id, label in options.items() if label == dummy_file.import_option ) menu_info["state"] = c4d.LV_CHECKBOX_ENABLED def SetDropDownMenu(self, root, userdata, dummy_file, column_id, entry): if column_id != ID_IMPORT_OPTION: return #this is logical but does not do the trick .... if not dummy_file.file_name.lower().endswith(".stp"): return options = { ID_IMPORT_OPTION_DEFAULT: "Default", ID_IMPORT_OPTION_HIGH: "High", ID_IMPORT_OPTION_MEDIUM: "Medium", ID_IMPORT_OPTION_LOW: "Low", } dummy_file.import_option = options.get(entry, dummy_file.import_option) self.dialog.tree_view.Refresh() class ListViewDropdownDialog(c4d.gui.GeDialog): def __init__(self): self.tree_view = None self.file_list_view = DummyFileListView(self) def CreateLayout(self): self.SetTitle(PLUGIN_NAME) tree_view_settings = c4d.BaseContainer() tree_view_settings.SetBool(c4d.TREEVIEW_BORDER, c4d.BORDER_THIN_IN) tree_view_settings.SetBool(c4d.TREEVIEW_HAS_HEADER, True) tree_view_settings.SetBool(c4d.TREEVIEW_HIDE_LINES, True) tree_view_settings.SetBool(c4d.TREEVIEW_RESIZE_HEADER, True) tree_view_settings.SetBool(c4d.TREEVIEW_FIXED_LAYOUT, True) tree_view_settings.SetBool(c4d.TREEVIEW_ALTERNATE_BG, True) if c4d.GetC4DVersion() >= 24000: tree_view_settings.SetInt32(c4d.TREEVIEW_VERTICAL_SPACE, 4) self.tree_view = self.AddCustomGui(ID_TREE_VIEW, c4d.CUSTOMGUI_TREEVIEW, "", c4d.BFH_SCALEFIT | c4d.BFV_SCALEFIT, 500, 220, tree_view_settings, ) if not self.tree_view: return False layout = c4d.BaseContainer() layout.SetLong(ID_FILE_NAME, c4d.LV_TREE) layout.SetLong(ID_IMPORT_OPTION, c4d.LV_DROPDOWN) self.tree_view.SetLayout(2, layout) self.tree_view.SetHeaderText(ID_FILE_NAME, "Dummy file") self.tree_view.SetHeaderText(ID_IMPORT_OPTION, "STP import option") self.tree_view.SetRoot(self.tree_view, self.file_list_view, None) return True def InitValues(self): self.tree_view.Refresh() return True if __name__ == "__main__": dialog = ListViewDropdownDialog() dialog.Open(c4d.DLG_TYPE_MODAL, 0, -1, -1, 500, 220)

Hey @lasselauch, no, that is unfortunately not possible. Unlike for the other big custom data type of Redshift RSFILE, the curve data type RSPFXCURVE does not implement Get/SetParameter to access internals of the data type, as you can for the file type with REDSHIFT_FILE_PATH. It also stands a bit to question how such lower desc level access should work here? Maybe as a lower level which can read/write the curve as SplineData? But I am not sure if this type would be faithfully convertable to SplineData`. I cannot fix this as Redshift is not part of the Cinema code base where the Python API lives. I gave one of the RS developers a bump so that they maybe can implement Get/SetParameter for that custom data type. Cheers, Ferdinand

You likely have to call UpdateOcioColorSpaces, just follow the example. There is btw no guarantee at all that DOCUMENT_COLOR_MANAGEMENT entails a render space of ACEScg. That is just the default, the user could have changed that. I am also not sure what all that RDATA_IMAGECOLORPROFILE code is meant to do. It depends a bit on what your plugin does and what self.IsForceLinear is meant to express. Only so much: An OCIO document does not necessarily entail a bitmap with a non-linear color profile, and OCIO also does not mean that the bitmap has to be 32bit. You are however missing UNDOTYPE_PRIVATE_DOCUMENTDATA undo management for setting the color management.

@ferdinand Okay, I will handle the plugins and files at an appropriate time.Thanks reply

@ferdinand Thanks for your detailed explanation. Although the precision conversion leading to value changes is not an error, it is indeed not what we want in terms of the results. For example, when dealing with the weight of some points, using SetWeightMap() will update the weights of other points, resulting in numerical changes. Only using SetWeight() can at least ensure that the weights of unoperated points do not undergo numerical changes (but using SetWeight() must tolerate the print warnings outputted by the console)

Hi, @ferdinand and @Anlv this is most awesome! All way beyond my capablities so thanks a lot for the scripts!

@ferdinand Thanks for your detailed explanation and the implementation of the sorting function. It's very helpful！

Thanks Anlv It looks like its adding the emitter into a null is what's causing it. Fixed with deferred CallCommand(1062577) (no sub-id (1067510) silently no-ops). Emitter fields greys if the emitter/group are parented under the setup null or generator. Sibling placement below plugin object + rename works fine.

What I meant was to use the Cineware Unreal bindings, but I am not sure if they support it. Going the export route is a big backwards when Cinema has specific bindings. https://www.maxon.net/en/cineware I will give the Unreal dev a bump when I see him again.

Yes I wanted submenu with Icon, thanks for Up to Date clarification.

This is not common knowledge, otherwise I would have spotted that earlier. So, you are not really expected to know this as a third party dev. You can look at the geometry_caches_s26.py example and there at this line, under [2] I mention that the cache of that object is muted. But that is of course only very indirect information and not enough to deduce this. I think we also talked about it a couple of times on the forum. The flag BIT_CONTROLOBJECT is set on input objects of generators, e.g., the to be extruded spline of an Extrude object, the profile and rail spine of a Loft object, the to be cloned cube and sphere objects of a MoGraph cloner, etc. As shown in the caching example, Cinema will mute the caches of input objects. To be very formal, they are actually built but then again deleted. BIT_CONTROLOBJECT marks such input objects. Your light in that scene should not have that flag, as it is not the input for some generator. But it somehow got it anyway, there is probably somewhere a bug. For normal scene evaluation that bug is also not really a problem (because as you saw from your own test, the light still converted correctly when you inserted it on its own outside of caches). The problems start when that irregularly as BIT_CONTROLOBJECT marked object is part of a cache. 'Make Editable' then incorrectly collapses the cache. Not only does it not stop at nested generators which are incorrectly marked like this, it also seems to apply the cache muting logic for input objects (resulting in the empty null object instead of the content of the cache of the collapsed generator). I already told the relevant devs that I consider this borderline buggy but they do not seem very inclined to do anything about this. What is effectively missing somewhere in cache resolvement is the evaluation if the flag BIT_CONTROLOBJECT 'makes sense on an object'. That is of not so easy to do, as generator - input object relations can be quite complex in Cinema. Which is probably also why the modelling team does not want to touch this. Cheers, Ferdinand

This is how I’ve implemented it at the moment, although users can’t drag and drop selection tags in the same way as with C4D’s built-in generator. Hope there are plans to expose the proxy tags. Thanks for tour time!

@ferdinand Yes, thanks, that indirect answer is enough for me. I was mainly wondering whether a check performed on both the client and the server is robust enough, or if it could be bypassed using Python, for instance. I’m well aware that it can be cracked somehow. I’m also already using ExportLicenses() for my node-locking system in combination. Thanks a lot for your help.

Hello @leah.hayes, 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 It is a bit difficult to answer you first question, as it is multiple questions of which some are open ended, please have a look at Support Procedures: How to Ask Questions for future postings. Where is the Python code of the built-in character templates ... They are stored in {c4d installation folder}/library.zip/characters. Is there a supported way to extract or view a built-in template (for example through c4d.modules.character.builder.Template) so I can study how the auto-adjustment is implemented? I am not quite sure that I follow. All these rigs are just our standard CA component system decorated with some Xpresso and Python. Since there can be literally hundreds of nodes in a rig, I attached below a little helper script to scan for specific Python content or just the scripts in general that are embedded somewhere in the rig. Is there a public API entry point to trigger or implement this kind of auto-adjustment for other templates? That auto adjustment seems to be some kind of Python script which the authors of this rig provided. These CA rigs have been created by (technical) artists and not the members of the Maxon development team. See the print out below for details on the artist code for "auto-adjustment". Cheers, Ferdinand Result ==================================================================================================== Node: Character Component (Character Component) | Attribute: (2158, 130, 1022113) Value: import c4d from c4d import gui import c4d.modules.character as ca import c4d.utils as utils #Welcome to the world of Python def Bl2DIterator(bl2D): while bl2D: yield bl2D for bl2DChild in Bl2DIterator(bl2D.GetDown()): yield bl2DChild bl2D = bl2D.GetNext() def SearchInHierarchy(obj, name): allChildrenWithName = [bl2D for bl2D in Bl2DIterator(obj.GetDown()) if bl2D.GetName() == name] return allChildrenWithName[0] def ShowLayer(layersList, showName): for layer in layersList: layerName = layer[c4d.ID_BASELIST_NAME] if showName in layerName: layer[c4d.ID_LAYER_VIEW] = True layer[c4d.ID_LAYER_MANAGER] = True def HideLayer(layersList, hideName): for layer in layersList: layerName = layer[c4d.ID_BASELIST_NAME] if hideName in layerName: layer[c4d.ID_LAYER_VIEW] = False layer[c4d.ID_LAYER_MANAGER] = False def CharacterAnimateMode(characterObject): characterObject[c4d.ID_CA_CHARACTER_COMPONENT_HIGHLIGHT_OVER] = 4 characterObject[c4d.ID_CA_CHARACTER_COMPONENT_MOUSEOVER] = 0 characterObject[c4d.ID_CA_CHARACTER_COMPONENT_VISIBLE] = 2 characterObject[c4d.ID_CA_CHARACTER_OM_DISPLAY] = 5 characterObject[c4d.ID_CA_CHARACTER_LOCK_AM] = False def CharacterEditMode(characterObject): characterObject[c4d.ID_CA_CHARACTER_COMPONENT_HIGHLIGHT_OVER] = 3 characterObject[c4d.ID_CA_CHARACTER_COMPONENT_MOUSEOVER] = 4 characterObject[c4d.ID_CA_CHARACTER_COMPONENT_VISIBLE] = 3 characterObject[c4d.ID_CA_CHARACTER_OM_DISPLAY] = 1 characterObject[c4d.ID_CA_CHARACTER_LOCK_AM] = True def CharacterBindMode(characterObject): characterObject[c4d.ID_CA_CHARACTER_COMPONENT_HIGHLIGHT_OVER] = 4 characterObject[c4d.ID_CA_CHARACTER_COMPONENT_MOUSEOVER] = 4 characterObject[c4d.ID_CA_CHARACTER_COMPONENT_VISIBLE] = 1 characterObject[c4d.ID_CA_CHARACTER_OM_DISPLAY] = 5 characterObject[c4d.ID_CA_CHARACTER_LOCK_AM] = True def CatchEmAll(obj, stop, listy): if obj is None: return #Actions go here if obj.GetType()==1019362: listy.append(obj) if not stop: if obj.GetDown(): CatchEmAll(obj.GetDown(), stop, listy) if obj.GetNext(): CatchEmAll(obj.GetNext(), stop, listy) return listy def SetGlobalRotation(obj, rot): """ Please remember, Cinema 4D handles rotation in radians. Example for H=10, P=20, B=30: import c4d from c4d import utils #... hpb = c4d.Vector(utils.Rad(10), utils.Rad(20), utils.Rad(30)) SetGlobalRotation(obj, hpb) #object's rotation is 10, 20, 30 """ m = obj.GetMg() pos = m.off scale = c4d.Vector( m.v1.GetLength(), m.v2.GetLength(), m.v3.GetLength()) m = utils.HPBToMatrix(rot) m.off = pos m.v1 = m.v1.GetNormalized() * scale.x m.v2 = m.v2.GetNormalized() * scale.y m.v3 = m.v3.GetNormalized() * scale.z obj.SetMg(m) def SetGlobalScale(obj, scale): m = obj.GetMg() m.v1 = m.v1.GetNormalized() * scale.x m.v2 = m.v2.GetNormalized() * scale.y m.v3 = m.v3.GetNormalized() * scale.z obj.SetMg(m) def ModeChanged(): characterObject = charop.GetObject() #Turning Off the Annotation # Main function leftAnnotationTag = SearchInHierarchy(characterObject, "LeftLeg_bind").GetLastTag() print(leftAnnotationTag) if leftAnnotationTag.GetType() == c4d.Tannotation: leftAnnotationTag[c4d.ANNOTATIONTAG_VIEWPORT_SHOW] = False #Hiding the Rig's Layers root = doc.GetLayerObjectRoot() #Gets the layer manager layersList = root.GetChildren() #Get Layer list for layer in layersList: layerName = layer[c4d.ID_BASELIST_NAME] if "Mixamo_Rig" in layerName: layer[c4d.ID_LAYER_VIEW] = False layer[c4d.ID_LAYER_MANAGER] = False mixamoLayers = layer.GetChildren() for layer in mixamoLayers: layerName = layer[c4d.ID_BASELIST_NAME] if "Retarget_Hierarchy" in layerName or \ "ANIMDATA_Nulls" in layerName or \ "Control Hierarchy" in layerName: layer[c4d.ID_LAYER_VIEW] = False layer[c4d.ID_LAYER_MANAGER] = False masterControl = SearchInHierarchy(characterObject, "Master_con+") hips = SearchInHierarchy(characterObject, "Hips") if nmode==c4d.ID_CA_CHARACTER_MODE_BUILD or \ nmode==c4d.ID_CA_CHARACTER_MODE_ADJUST: CharacterEditMode(characterObject) if nmode==c4d.ID_CA_CHARACTER_MODE_BIND: CharacterBindMode(characterObject) if nmode==c4d.ID_CA_CHARACTER_MODE_ADJUST and omode==c4d.ID_CA_CHARACTER_MODE_BUILD: #Changed search method to only search in Character Object #hips=doc.SearchObject("Hips") #masterControl=doc.SearchObject("Master_con+") #added Namespace Code nameSpace=masterControl[c4d.ID_USERDATA,16] results=CatchEmAll(hips, hips.GetNext(), []) for result in results: mixamo=doc.SearchObject(nameSpace+result.GetName()) if mixamo: matR = result.GetMg() matM = mixamo.GetMg() matR.off = matM.off matR.v1 = matM.v1.GetNormalized() matR.v2 = matM.v2.GetNormalized() matR.v3 = matM.v3.GetNormalized() result.SetMg(matR) if result.GetName()=='Neck1': #neck=doc.SearchObject(nameSpace+'Neck') #head=doc.SearchObject(nameSpace+'Head') neck = SearchInHierarchy(characterObject, nameSpace+'Neck') head = SearchInHierarchy(characterObject, nameSpace+'Head') if head and neck: result.SetMg((neck.GetMg()+head.GetMg())/2) print("Auto-Adjustment Complete") #Turning On the Annotation if leftAnnotationTag.GetType() == c4d.Tannotation: leftAnnotationTag[c4d.ANNOTATIONTAG_VIEWPORT_SHOW] = True if omode==c4d.ID_CA_CHARACTER_MODE_ADJUST and nmode!=c4d.ID_CA_CHARACTER_MODE_BUILD: L_Leg=doc.SearchObject("Left_IK_parent_rot_algn") #L_Leg = charop.FindObject("Left_IK_parent_rot_algn") if L_Leg: conTag=L_Leg.GetFirstTag() conTag[c4d.EXPRESSION_ENABLE]=False R_Leg=doc.SearchObject("Right_IK_parent_rot_algn") #R_Leg = charop.FindObject("Right_IK_parent_rot_algn") if R_Leg: conTag=R_Leg.GetFirstTag() conTag[c4d.EXPRESSION_ENABLE]=False if nmode==c4d.ID_CA_CHARACTER_MODE_ANIMATE: CharacterAnimateMode(characterObject) doc.SetActiveObject(masterControl, c4d.SELECTION_NEW) c4d.EventAdd() Code """Scans the document for all nodes that have multi-line string parameters that contain the word "adjustment" (case-insensitive) and prints the node name, type, parameter ID, and value to the console. """ import c4d import mxutils doc: c4d.documents.BaseDocument def main() -> None: """ """ node: c4d.BaseList2D pid: c4d.DescID # Iterate over all objects and tags in the document that live outside of caches and within the # object branch of the document. for node in mxutils.RecurseGraph(doc.GetFirstObject(), yieldBranches=True, yieldHierarchy=True, branchFilter=[c4d.Obase, c4d.Tbase]): # Iterate over the description, i.e., parameters of the node. for data, pid, _ in node.GetDescription(c4d.DESCFLAGS_DESC_NONE): # The first level of this parameter is not of type string or does not use the # multi-line string GUI, so we skip it. if pid[0].dtype != c4d.DTYPE_STRING or data[c4d.DESC_CUSTOMGUI] != c4d.CUSTOMGUI_STRINGMULTI: continue # Try to read the value, the exception block is needed as not all parameter types are # accessible in Python (and this could be some kind of exotic multi level string data type). try: value: str | None = str(node[pid]).strip() if not isinstance(value, str) or not value: continue except Exception: continue # Check if the value contains the word "adjustment" (case-insensitive), if not, skip it. if "adjustment" not in value.lower(): continue # Print the match. print ("\n\n" + ("=" * 100)) print (f"Node: {node.GetName()} ({node.GetTypeName()}) | Attribute: {pid}\n\nValue:\n\n{value}") # For good measure, select the node and break the loop. (doc.SetActiveObject(node, c4d.SELECTION_NEW) if isinstance(node, c4d.BaseObject) else doc.SetActiveTag(node, c4d.SELECTION_NEW)) break c4d.EventAdd() if __name__ == '__main__': main()

@DronKozy Yeah, I got the general direction, that you are probably implementing a material mixer type of material/shader. When you implement a full render engine binding, you should go the event notification route, as I am sure you can then easily handle the (slight) complexity that comes with them. Regarding the architecture, in principle you can do with whatever you want. As Maxon employee I would of course recommend to use our Nodes API (what you call 'native'). The SDK contains both code examples and documentation about this. But this biggest flaw of the Nodes API is probably that it is not entirely non-trivial. But implementing a full node editor also requires a relatively high level of expertise about our APIs, although in different areas. Currently Redshift, Vray, Arnold, and CentiLeo use the Nodes API and all other render engines (Corona, Octane, Cycles, etc.) use either a completely custom system or the old Xpresso Nodes API. Cheers, Ferdinand PS: When you are developing a render engine binding, you might want to consider our Maxon Registered Developer Program.

I don't know what your script does and if it needs fixing for 2026.3. What I said is that we usually put a lot of effort into keeping our ABIs and APIs stable, as exemplified with the 2026.3.1 hotfix where we fixed an issue with the UV tag interface that made it incompatible with old code. 2026.3 contained the UV manager overhaul as its main feature. We tried not to break any glass there but I cannot rule it out. when you find a regression in our APIs, you can also always report it. when the break was unintentional we usually provide a fix (in critical cases even a hotfix) or at least a workaround. We also usually do not remove systems. For example, the old content system and its "Content Browser" is still in our APIs and Cinema, although it long has been replaced by the Asset Browser and API. Can I guarantee that the UVPeeler will not be removed soon? No, we sometimes have to remove things. But it is quite rare.

Hey @ECHekman, well, when a node displays an embedded description (what you exemplify at the case of a BaseLink), it uses a DescriptionCustomGui too. Other parameter types aside from a BaseLink which can do this are for example field lists. I am quite frankly a bit surprised that this even bubbles up in the form you report it, that you get a DescID which is selected inside a DescriptionCustomGui that is shown by the node in the DescriptionCustomGui you opened yourself. Attribute Manger selection states (and by extension DescriptionCustomGui) are not a public API feature, as we usually keep our GUIs sealed, i.e., inaccessible to third parties. DescriptionCustomGui is here a bit in a grey area, but I am afraid there is no way to do what you want to do. To do what you want to do, you would need access to internal systems. And other than in some other cases, where we do not always had the time to expose something (and are open to the idea of changing something), this is for GUIs not the case; they are intentionally sealed as we do not want third parties to change basic UX concepts. My general advice would also be to not to try to overcome this boundary (that a plugin reacts to which parameter in a node is being highlighted by the user), as you break UX conventions of Cinema 4D with that. Cheers, Ferdinand You can do this, but it is very hacky: Get the description of the node(s) you are currently displaying in the your DescriptionCustomGui. Check if desc is a member via CheckDescID (I think GetParameter would also work and return an empty container when the ID does not exist). When the ID does not exist, start browsing the container for parameters that are of a DTYPE that implies an underlying node, such as DTYPE_BASELINK. When you find such parameter, get the node node, and check there. Rinse and repeat recursively. Issues: You cannot distinguish the case where an object A has two BaseLink parameters which both hold an object of type T, but not the same instances. You will run into issues with DescID translations which some nodes might do. This is a really big point, which is probably already overlooked in your current code. Nested node relations can get REALLY complicated. BaseLink is trivial, but stuff like field lists, volume lists, or some special shader stuff can get really complicated. You would probably only have to worry about base links and field lists in your case, as other renderers are irrelevant for you, but field list alone are already complex enough that I would strongly advise against 'just implementing it'.

Hey @ferdinand , Sorry I forgot click Submit button well, that is the info I need, I use same tech to get icons for CMD, and now waiting for svg part in the future. Cheers~ DunHou

Okay, I think I was a bit overly cautious in my answer here. You gave my a very broad question, or to be precise, you gave me a video and a scene file, and did not really ask a precise question. I understand that asking good questions can be hard, especially with a language barrier. But when I have nothing to go by, I of course assume the worst case possible. The scene you have there is a trivial case, even the best case possible. You have there spline segments which lie in a perfect plane and which have no self intersections. You can treat them just like polygons (in the CG sense, not in the mathematical sense) and simply compute their normal over the first three vertices of each segment. Due to the fundamental property of a polygon - reversing the order of the vertices reverses the normal - you can then easily determine if two segments have opposite or equal winding. But all this starts to fall apart, as soon as you cannot make these assumptions. And I cannot help you to write the code for this, as this is then more than just a few lines. Hope this helps, and that I my answer was now less 'overly cautious'. Cheers, Ferdinand Result [image: 1780950951310-85f415e7-7f45-4c00-9651-b4091ee543e2-image.png] The code correctly identifies that in this six segment spline are four segments of one winding direction (clockwise in this case) and two of the other winding direction. winding_direction.c4d Code """Treats spline segments as polygons and compares their plane normals to find segments with reversed winding order. """ import c4d op: c4d.SplineObject # The currently active object in the scene. def main() -> None: """Called by Cinema 4D when the script is being executed. """ if not isinstance(op, c4d.SplineObject): return c4d.gui.MessageDialog("Please select a spline object.") # Get all points in the spline and organize them into their segments. points: list[c4d.Vector] = op.GetAllPoints() segments: list[list[c4d.Vector]] = [] j: int = 0 for i in [op.GetSegment(i)["cnt"] for i in range(op.GetSegmentCount())]: segments.append(points[j:j+i]) j += i if len(segments) < 2: return c4d.gui.MessageDialog("Please select a spline object with at least 2 segments.") # Now build normal data for the spline segments. This assumes: # # - A spline where all points lie in a single plane, a '2D' spline in 3D space. # - No self intersections in the spline. # - A piecewise linear spline, i.e., what Cinema 4D calls a 'Linear' spline. When we have a # 'Cubic' or 'Bezier' spline, we would have make it linear with 'Current State to Object' # first. # # We build the normal for each segment over its three first vertices. The reason why we are doing # this is because of the fundamental identity of a polygon (in a computer graphics sense), # reversing the order of the vertices of a polygon will reverse the normal. So if we have a # spline with two segments with reversed winding order, they will have antiparallel normals (normals # pointing in opposite directions). segmentNormals: list[c4d.Vector] = [] for segment in segments: if len(segment) < 3: print("Segment has less than 3 points, skipping normal calculation.") continue a, b, c = segment[0], segment[1], segment[2] edge1: c4d.Vector = b - a edge2: c4d.Vector = c - b normal: c4d.Vector = edge1.Cross(edge2).GetNormalized() segmentNormals.append(normal) # Now we just declare one segment as 'ground truth' and check if the other segments have normals # that are parallel or antiparallel to it. When we found a segment with an antiparallel normal, we # know we found a segment with reversed winding order. To check if two normals are parallel or # antiparallel, we just compute their dot product (i.e., spanned angle). When the dot product is # negative, the normals are antiparallel. print(f"Establishing the first segment normal {segmentNormals[0]} as ground truth.") baseNormal: c4d.Vector = segmentNormals[0] for i, normal in enumerate(segmentNormals[1:], start=1): isAntiparallel: bool = baseNormal.Dot(normal) < 0 print(f"Segment {i} normal: {normal} is {'antiparallel' if isAntiparallel else 'parallel'} " f"to the base normal {baseNormal}.") if __name__ == '__main__': main()

That is of course also a valid option, just pick the scripting language you are most comfortable with.