Hey @ECHekman,

Thank you for reaching out to us.

@ECHekman said in Getting debugbreak in atom.cpp:

Here is how i create the UI

// in MyData::GetDDescription() BaseContainer bc = GetCustomDataTypeDefault(DA_CONTAINER); bc.SetInt32(DESC_CUSTOMGUI, CUSTOMGUI_OCIOCYCLE); bc.SetString(DESC_NAME, String(pinInfo->mStaticLabel)); bc.SetBool(DESC_SCALEH, TRUE); description->SetParameter(IDCopy, bc, groupID);

That, the GetCustomDataTypeDefault(DA_CONTAINER) call, is illegal code. Check our documentation for the function. It could probably be put a bit more verbosely into the docstring, but:

cb400f4a-9cf9-43eb-83b2-0bd37b7127f8-image.png

DA_CONTAINER is not a resource data type. Which is a fancy way of saying that a C4DAtom parameter cannot be of data type DA_CONTAINER. On line 439 in atom.cpp is no crit stop (at least in the version of atom.cpp for 2025.2.x.yyyyyy I looked at), but on line 476 there is. This is inside C4DAtom::SetParameter, and it gets there the ID of the parameter container of the description element which shall be written, then switches through all the atomic DTYPE_ and when none matches, calls at the end FindResourceDataTypePlugin() on the ID of the parameter container, i.e., what you initialized as DA_CONTAINER. When it cannot find anything there, it raises the crit stop.

When you want to have there some OCIO data bundle, you probably should also implement a data type for it. Otherwise you should try DTYPE_SUBCONTAINER. But I am not sure how nicely DTYPE_SUBCONTAINER will play with custom GUIs. In general I would lean towards that writing a container as a singular parameter with a GUI like this is not intended, but you can try your luck. What will work in any case, is implementing your own data type.

And to be verbose, a resource data type is a data type that can be used in resources, i.e., res files.

Cheers,
Ferdinand

Thank you very much @ferdinand for your suggestions—I really appreciate your input and support. I will definitely experiment with your leads and see what works best for me. It’s always helpful to get an outside perspective, and your advice has given me some new things to think about. Thanks again!

Hey,

Please note that both options, a modifier that changes the number of points of its host, and a spline generator that has another spline as an input, are not great. We have internally two cases that do exactly these two things: The bevel deformer and the spline mask spline generator. But third parties do not easily replicate both because they require detailed knowledge of our API and in some cases access to non-public things.

For deformers, Ilia already gave a great explanation. In short, if you are not careful, you can crash Cinema 4D. For the other case, a spline generator which takes another spline as an input, you will run into the issue that splines are not intended to have as objects as inputs. This means you are not getting passed a HierarchyHelp in ObjectData::GetContour with which you could ensure that your child object dependencies are up to date (because by default they are being built after you). There are patterns to solve this, and you run here at worst into the problem of a laggy/malfunctioning plugin and no crashes. But I would still advise going down that rabbit hole when avoidable.

When you really must do this and now want to go down the spline generator road, I would recommend opening a new topic on that before you start.

Cheers,
Ferdinand

Tried to send the crash report on 6/6/25 at 22:08 but I got a message saying there was a problem sending it. The message also says to send it by email so I've sent it to sdk_support(at)maxon(dot)net.

Steve

Hey @bojidar,

I would suggest that you write a mail about this, so that I can forward it. All I can tell you is that for variadic ports all bets are off. I really ran into this issue when I had to handle variadic ports for graph descriptions.

When you instantiate a node with variadic ports, it usually has some default children. I have never tried what happens when you try to remove all ports (graph description can do this, but they then do not test if the system does not regenerate them). There is also no guarantee that the 1st variadic port has the ID _0. It is just a convention, which is for example directly borken by the Standard Renderer Material node, as it gives its first BSDF layer port the ID 1, and the 2nd manually created layer then the ID _0 (because of course it does):

76bb0bfe-ff1f-4530-a55c-059bc195e46b-image.png
1aa63fb8-e9dc-4e83-80b6-7ffa782752af-image.png

You really have to write a mail here, because this is so deep in the Nodes API internals, it requires a true specialist to answer it.

Cheers,
Ferdinand

Hey @ECHekman,

well, I was talking about User Data, as they can be a nice way to inspect what data types and their custom GUIs can do.

c72e5dab-e512-48cb-8333-95ccee722325-image.png

For what you want to do, this will however not help, as there are only the description settings listed, which necessarily do not have to be all settings there are. To start with an expanded GUI, you must set LAYOUTMODE_MAXIMIZED. I think the little toggle arrows are not supported in dialogs, but I might be wrong. When you want to know more about the little toggle arrow, I would suggest to write us a mail, so that I can forward it to a GUI specialist, as I do not know if and how you could make the arrow work.

This is one of the cases how we internally setup such GUI in a dialog, maybe this already helps (but there are many, and they are not all the same). The a bit odd looking SetInt32('abcd', value)` thing, where we express an Int32 ID as four chars is something we sometimes do internally. Some people find it apparently easier to read/handle than symbols. It often also means that there is no proper integer value and symbol for that ID.

void MyDialog::AddColorAlphaChooser(Int32 id, Int32 flags, Int32 layoutFlags) { BaseContainer colorUISettings = GetCustomDataTypeDefault(DTYPE_COLORA); colorUISettings.SetInt32(CUSTOMGUI_LAYOUTMODE, LAYOUTMODE_MAXIMIZED); colorUISettings.SetInt32('iccc', layoutFlags & (DR_COLORFIELD_ICC_BPTEX | DR_COLORFIELD_ICC_BASEDOC)); colorUISettings.SetInt32('cfld', layoutFlags); AddCustomGui(id, CUSTOMGUI_COLOR, String(), flags, 0, 0, colorUISettings); }

Cheers,
Ferdinand

Hey @felixc4d,

You inheriting from AioReaderRef does not make too much sense. The Maxon API uses interfaces and references. A reference just points to an interface object and increases its reference count, so that the object can be garbage collected once its ref-count reaches zero. References are almost never manually implemented but implemented automatically by the source processor. So, the thing you declare and inherit from is the interface. But that as its name implies, it is actually only the interface and usually is not the actual implementation.

The Maxon API mostly uses components to implement relevant functionalities. Components are elements that are loaded dynamically into interfaces at runtime and effectively realize composition over inheritance. So, you can have a FooRef a and a FooRef b for two FooInterface objects which act completely differently at runtime, because the interfaces have different components loaded which realize them.

I guess you want to override the NotifyForRead function of AioReaderInterface. For that you would have to write a component for AioReaderInterface and then load it at runtime into an object of one of its concrete forms such as NetworkUdpServerInterface. When I look at for example NetworkUdpServerImpl (the component for NetworkUdpServerInterface), you are sort of in luck, as that component has not been marked as final, so you at least technically have the ability to load another component in there without the interface refusing that.

But when you realize a component, you must realize all the MAXON_METHOD methods of the interface the component is for, so you cannot just overwrite that one method. There are way and techniques around this, but then we really reach internal/non-public territory.

I could here into more detail but that is all a bit pointless, because when you do this for NetworkUdpServerInterface and its client counter part, you will just end up again at ReadToBuffer shown above. Because what you have to customize in the end, is the call to the native OS library functions and these are burried deep within our non-public code, so you cannot change that from the outside.

I am afraid you must either use another protocol, you said that TCP worked fine for you, or really implement things yourself. I am also not really convinced that you cannot communicate in chunks of 1kb, as you can split up and reassemble things. Finally, the last option would be to just use a third party library which wraps at least Windows and macOS for you (not sure if you want to support Linux).

Cheers,
Ferdinand

I actually quite like the Apple keyboard, even if Apple’s idea of a UK keyboard is different to everyone else. For example, shift-2 should produce a “ character but on this Apple kit, it’s the @ symbol. The odd key bindings just make it worse, but it’s a nice keyboard.

But I detest the Apple Magic Mouse, I can’t get used to those ‘gestures’. Give me my Logitech trackball any time. A bit of extra software does make a Mac so much more useful though. Pathfinder is way better than the horrible Finder, and BetterZip is very user-friendly.

Thanks for the reply @i_mazlov. Yeah, I already tried the workaround, it worked.

@ferdinand
Thanks for the response, I figured that would be the case.

John Thomas

Hi @madfx,

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

I'm sorry for the delayed answer.

Unfortunately there's no existing public API that would allow you to do that.

Cheers,
Ilia

Thanks Ferdinand, that was kind of what I expected the awnser to be. I'll use a creative solution that doesnt trigger an unnessesary recreation of the Extrude cache

@ferdinand
Thanks for the detailed response, unfortunately what I'm trying to do doesn't seem viable.

John Thomas

Hey @T1001,

I am still not 100% sure how you all mean that. But in short what you are doing is not possible in the public API and also only to some degree in the internal API. First of all, Cinema 4D only supports HDR in the viewport and it must be enabled by the user:

image.png

I.e., viewport effectively means Drawport API. What the docs write there about the only the viewport is only semi true, because you can embed a drawport into a GeDialog (but that functionality is still not even semi-public I think, but we could change that in a future release).

I am not quite sure what you mean by 'integrating a custom OpenGL pipeline into a plugin'. When I take this at face value, I would say you cannot do this. The Drawport API is an abstraction around effectively Vulkan and Metal. We do not write OS specific graphics API code anymore. This goes as far as that we have (sort of) our own shading language (MSL). You cannot just draw with OpenGL into a GeDialog, because that dialog will not be drawn with OpenGL and we also do not offer a direct access point to drawing handlers.

I assume this all has something to do with implementing some kind of render buffer? I really would recommend then applying for the Maxon Registered Developer program to get access to the Drawport API. Just as a warning ahead, the Drawport API is not totally undocumented but not documented to the same degree as our fully public API. It is an API from graphics API experts for graphics API experts. You seem fairly knowledgeable there, so this might be just your thing, but you have been warned, there will be less hand-holding there.

Cheers,
Ferdinand

Hi @ferdinand,

Sorry about missing that post. This exactly solved my problem, thanks.

Dam

Love the mxutils and GeDialog Changes, I use these features almost every time, thank you for having a more refined official version.

Thank you to the SDK team for their work achievements

Cheers~
DunHou

Hey @skibinvitaliy,

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

No one is judging you here, problems are part of the game and what we are here for to help with 🙂 . But please familiarize yourself with our forum rules, such question should be accompanied by example code and the version you are migrating from, as we otherwise mostly have to guess what is going wrong.

I am assuming you are migrating from a pre-2025 SDK, that is at least what your errors imply. With 2025 we introduced our cinema namespace. Please follow our Migrating Plugins to the 2025.0 API guide. You are likely just missing a couple of using namespace cinema; at the top of your files.

Cheers,
Ferdinand

Hey,

it seems I was a bit too tightlipped here. So in more verbose: You cannot customize the chosen unit of a parameter. This is impossible as this is a globally set value (which is also just smoke and mirrors as explained in the link above). There is a UnitScale custom GUI but it does not what you want, it is the field used in the document settings and is not really meant to store a value and unit but just a unit.

image.png

When you really-really-really want this, you can implement you own custom GUI, either targeting your own custom data types or existing data types. There you could then do whatever you want. But that might not mesh so well with the rest of Cinema 4D, given that Cinema 4D does not operate like that.

Cheers,
Ferdinand