Thanks for your advice.
The build is complete.
It was because VS2017 when Unity was installed was old.
Now you can build other plugins.
Thank you very much.

1. I retargeted because the SDK version was 8.1.

2. All projects have been changed to the new Windows SDK.

3. I created a project with kernel_app_64bit.exe of project_tool.

I built it without changing the SDK version again, but I still get an error around core.framework.

Isn't it possible to get sdk.zip that can be built normally because it is useless here and there?

thank you for contacting.
Here are the steps I took:
My environment is Windows 10 & Japanese & CINEMA4D R21.026

1. Download Project Tool for Cinema 4D R21 and place it under C drive

c: \ project_tool21

2. After installing R21, extract sdk.zip under C drive

c: \ sdk21

3. Run the command to move to the Project Tool at the command prompt

kernel_app_64bit.exe g_updateproject = c: \ sdk21

4. Open plugins.sln and start VS2017

C: \ sdk21 \ plugins \ project

5. Retargeting the solution to change the Windows SDK version to 10.0.16299.0

6. Run solution build

If you build R21 SDK as it is in VS2017, an error will occur and you will not be able to build.

1> Looking for source files in C: \ sdk21 \ frameworks \ core.framework ...
1> register.cpp
1> c: \ sdk21 \ frameworks \ core.framework \ generated \ hxx \ interfacetemplate2.hxx (209): error C3861: 'PrivateGetInstantiationId': identifier not found
1> c: \ sdk21 \ frameworks \ core.framework \ generated \ hxx \ interfacetemplate2.hxx (209): error C3861: 'PrivateGetInstantiationSourceName': identifier not found
1> c: \ sdk21 \ frameworks \ core.framework \ generated \ hxx \ interfacetemplate2.hxx (213): error C3861: 'PrivateGetInstantiationId': identifier not found
1> c: \ sdk21 \ frameworks \ core.framework \ generated \ hxx \ interfacetemplate2.hxx (400): error C3861: 'PrivateGetInstantiationId': identifier not found
1> c: \ sdk21 \ frameworks \ core.framework \ generated \ hxx \ interfacetemplate2.hxx (400): error C3861: 'PrivateGetInstantiationSourceName': identifier not found
1> c: \ sdk21 \ frameworks \ core.framework \ generated \ hxx \ interfacetemplate2.hxx (404): error C3861: 'PrivateGetInstantiationId': identifier not found
1> Build of project "core.framework.vcxproj" finished-failed.

The Project Tool used was the Project Tool for Cinema 4D R21, and the sdk.zip that came with R21.026 was used.

How can this be solved?

Re: Copy link object

This is the code I wrote.

BaseObject *HyperINS::GetVirtualObjects(BaseObject *op, HierarchyHelp *hh)
{
        BaseContainer* bc = op->GetDataInstance();
	BaseObject* main = BaseObject::Alloc(Onull);
	if (!main) return nullptr;
	
	BaseObject    *link= (BaseObject*)bc->GetLink(ID_LINK, hh->GetDocument());
	if (!link) return main;
		
	AutoAlloc<AliasTrans> aliastrans;
        if (!aliastrans || !aliastrans->Init(hh->GetDocument())) return main;
        
        BaseObject* ref = static_cast<BaseObject*>(link->GetClone(COPYFLAGS::NONE, nullptr));

        aliastrans->Translate(true);

        ref->InsertUnder(main);
		
	return main;
}

It will not work at the manager's position.

Hi.

I copied the object of link field in the virtual object with GetClone ().

However, if the type of the linked object is a generator type such as instance, it can not be displayed properly below the linked object on the object manager.

I checked past posts and found that they have priority issues.
But I do not know how to solve it.

https://developers.maxon.net/forum/topic/6250/6615_clone-of-a-linked-object

Please let me know if anyone knows who you are.

Error did not come out safely.
I did not understand how to use projectdefinition.txt.
You can proceed with this.
Thank you very much.

I do it in the following procedure

1. Create project file with project_tool

2. Add network.framework to frameworks

3. Add path in include directory from project properties![alt text]
   \ sdk \ frameworks \ network.framework \ source
   \ sdk \ frameworks \ network.framework \ generated \ hxx

I could write #include "maxon / network_smtpmail.h" and load it successfully.
But then I get a message that SmtpErrorInterface and SmtpMailInterface can not be resolved.

There was an error when opening network_smtpmail1.hxx and network_smtpmail2.hxx.

How can I do this?

I added network_smtpmail.h, but when I build it
LINK 2001 error has occurred.
External symbol "" public: static class maxon :: InterfaceReference maxon :: SmtpErrorInterface :: _ interface "(? _Interface @ SmtpErrorInterface @ maxon @@ 2VInterfaceReference @ 2 @ A)" is unresolved

How can I solve this?