Thanks Ferdinand. Putting those lines in the projectdefinitions.txt of the solution was the... solution

DTYPE_VECTOR4 and DTYPE_COLORA are not maxon::data types internally in c4d.
When I get or set them as maxon::data like your example code the GeData changes to a DTYPE_DATA instead
Additionally the existing 4d colorpicker GUI for DTYPE_COLORA will override the maxon::data type and reset it to whatever DTYPE_COLORA is internally.

Ok thanks for the help Ferdinand. I will take the road of least resistance and just build on top of float64 vectors

I made this separate thread specifically because of the clear singular question rule i have been told to follow. And this is a different question from the question on custom data types.

This is a different question from:
https://developers.maxon.net/forum/topic/15823/data-datatypes-python-and-gui/6?_=1732092863717

If you are referring to the same post i wrote on the backstage forum the suggestion i got there does not work:

const ColorA* color = data.GetCustomDataType<ColorA>();

^^ this does not work

I am asking how to use existing types here. And not new/custom ones
Specifically the DTYPE_COLORA and DTYPE_VECTOR4 and not the regular types DTYPE_COLOR and DTYPE_VECTOR

How do I get and set Vector4 and ColorA to the basecontainer/gedata?
I have tried pretty much every possible function and method but I dont seem to be able to use Vec4/Color4.

I have managed to get it via unsafe c-style casting:

	GeData ge(DTYPE_COLORA, DEFAULTVALUETYPE::DEFAULTVALUE); // Create
	
	// Get
	const CustomDataType* customPtr = ge.GetCustomDataTypeI(DTYPE_COLORA);
	maxon::ColorA color = *(maxon::ColorA*)customPtr;

	// Set
	color = maxon::ColorA(0.5, 0.1, 0.6, 0.7);
	CustomDataType* customPtrDst = (CustomDataType*)&color;
	ge.SetCustomDataTypeI(DTYPE_COLORA, *customPtrDst);

	// Get again to check if it worked
	const CustomDataType* customPtr2 = ge.GetCustomDataTypeI(DTYPE_COLORA);
	maxon::ColorA color2 = *(maxon::ColorA*)customPtr2;

But this is basically undefined behavior

Just to clear something up that you wrote: maxon::IntVector32 is not a new template specialization.
And are you sure maxon::IntVector32 is not wrapped in python. It is in the python sdk?
https://developers.maxon.net/docs/py/2025_0_0/modules/maxon_generated/datatypes/vec_col_mat/maxon.IntVector32.html?highlight=intvector32#module-maxon.IntVector32
Or am I missing something here?

I have the UI working for the pre-existing maxon::IntVector32 data type. The only problem with this method is that when i animate it, it does not interpolate between multiple keyframes - it just jumps from one to the other.

The problem im trying to solve is that Octane supports these other types (int3 float4 long2 etc). But from what I now learned, and reading your answers, I will either need to chose between:

• Use Custom Data Type - dropping python support
• Use maxon::IntVector32 - dropping keyframe interpolation support
• Cast everything from Vector4d to int vectors and in64 vectors - possible data loss and clunkyness by having to set int values with floats in python

Btw, I recently got backstage access, would it be better to ask these questions there?

I have two problems with using maxon::data route

For instance I have tried to do int32_3 by using maxon::IntVector32. Which is maxon::Vec3<maxon::Int32, 1>;

1. However this type does not seem to support interpolating between keyframes
2. I cant seem to dynamically create GUI for it
   For example: This is how i generate UI for the bool checkbox:

const DescID cid = CreateDescID(DescLevel(guiID, DTYPE_BOOL, 0));
BaseContainer bc = GetCustomDataTypeDefault(DTYPE_BOOL);
bc.SetInt32(DESC_CUSTOMGUI, CUSTOMGUI_BOOL);
 bc.SetString(DESC_NAME, name);
bc.SetBool(DESC_SCALEH, scaleH);
bc.SetBool(DESC_FITH, fitH);
bc.SetInt32(DESC_ANIMATE, anim);
description->SetParameter(cid, bc, CreateDescID(DescLevel(groupID)));

How would i do the same for maxon data types?

For the project I am working I would like to add new data types to the BaseContainer/GeData for a ShaderData and I'm wondering what the best method for storing, displaying, animating and python interop.

The types I want to add are the following vectors:

Int32_2,    Int32_3,    Int32_4
Float_2     Float_4     
Int64_2

I have tried 3 methods so far:

Method 1: CustomDataType from the sdk example:
I implemented this for Int32_3. This one is the most promising so far as it gives me the greatest level of control over the data and GUI.
Drawbacks:

• I am not sure how to set/get this data from python or other plugins?
• Would much prefer to have proper integrated types like maxon::IntVector32

Method 2: maxon::data types (IntVector32)
I tried IntVector32 and Vector4d for Int32_t and Float_4. The data can be set with the SetMaxonData function or SetData on GeData. This method seems to the most integrated, and these types also exist in python?
Drawbacks:

• There seems to be no GUI for these types?
• They are not interpolated between keyframes
• I dont know how to properly add new GUI for these types as they do not have DTYPE_ value?

Method 3: DTYPE_VECTOR4 / DTYPE_COLORA / DTYPE_VECTOR2
These have GUI.
Drawbacks:

• I cannot set or get the data from the BaseContainer. There is no GetVector4. And im not sure how to extract this data from the GeData.
• There are no int32 or int64 versions of these

Hopefully you can help me out on navigating this issue.
I would much prefer to use official data types, but im happy to implement my own custom data types. However I am not sure how these properly interop with python and other plugins.

Thanks Ferdinand. Putting those lines in the projectdefinitions.txt of the solution was the... solution

Im trying to get the natvis files to work, and I added the settings from the documentation.
However this does not seem to do anything. Is there something im missing?

AdditionalSolutionFiles=\
..\..\frameworks\core.framework\project\typeviewer\msvc\maxon.natvis;\
..\..\frameworks\cinema.framework\project\typeviewer\msvc\c4dapi.natvis

I have gotten it to work by manually adding the natvis to the visual studio document folder, but i would like to automate it.