@zipit I have Optimize call at the end of ModifyObject(). It makes a little difference if i call it or not. With Optimize plugin works stable for a random amount of time. Without Optimize it is instant crash. Here is Optimize code, although it is pretty similar to Disconnect.

Bool DeformerPlugin::Optimize(BaseObject* main, BaseThread* thread) {
        BaseSelect* select = ToPoly(main)->GetPolygonS();
	select->DeselectAll();
	AutoAlloc<BaseDocument> basedocBuffer;
	BaseObject* clonedOp = (BaseObject*)main->GetClone(COPYFLAGS::NONE, nullptr);
	basedocBuffer->InsertObject(clonedOp, nullptr, nullptr);
	basedocBuffer->ExecutePasses(thread, true, true, true, BUILDFLAGS::INTERNALRENDERER);
	ModelingCommandData mcd;
	BaseContainer bc1;
	bc1.SetData(MDATA_OPTIMIZE_TOLERANCE, 0.);
	bc1.SetData(MDATA_OPTIMIZE_POINTS, true);
	bc1.SetData(MDATA_OPTIMIZE_UNUSEDPOINTS, true);
	bc1.SetData(MDATA_OPTIMIZE_POLYGONS, true);
	mcd.doc = clonedOp->GetDocument();
	mcd.op = clonedOp;
	mcd.mode = MODELINGCOMMANDMODE::POLYGONSELECTION;
	mcd.flags = MODELINGCOMMANDFLAGS::NONE;
	mcd.bc = &bc1;
	if (!SendModelingCommand(MCOMMAND_OPTIMIZE, mcd)) {
		ApplicationOutput("Optimize error."); 
		return false;
	}
	clonedOp->CopyTo(main, COPYFLAGS::NONE, nullptr);
	return true;
}

Yeah, and without using document buffer it is instant crash in both cases.

I've tried to use COPYFLAGS::CACHE_BUILD for both Optimize and Disconnect but didn't make a difference.

I'm new in plugin development and don't really understand how cinema 4d pipeline works in details. Is ModifyObject() creates new object each iteration or just modifies it? Which functions does ObjectData call and in which order? So many questions, so few answers.

@zipit Thanks for your reply! I tried to do it without copying matrixes and tags, but as i was expecting that didn't make any difference.

I understand that isoparms probably have nothing to do with it, but still a crash appears after choosing isoparms for some reason.
I'm not sure it is related to CopyTo because the same problem occurs either with or without document buffer. But i can't deny that your guess can be right.

Hello! I have a problem with my deformer plugin.
Plugin not only deforms shape of an object, but also adds new polygons and points to it.
Problem appears when i try to use isoparms mode.
What i figured out:
Problem was in SendModelingCommand(). It was solved by making new document, executing passes and copy to original object.

Bool DeformerPlugin::Disconnect(BaseObject* main, BaseThread* thread) {
	BaseSelect* select = ToPoly(main)->GetPolygonS();
	select->DeselectAll();
	AutoAlloc<BaseDocument> basedocBuffer;
	BaseObject* clonedOp = (BaseObject*)main->GetClone(COPYFLAGS::NONE, nullptr);
	basedocBuffer->InsertObject(clonedOp, nullptr, nullptr);
	basedocBuffer->ExecutePasses(thread, true, true, true, BUILDFLAGS::INTERNALRENDERER);
	ModelingCommandData mcd;
	BaseContainer bc;
	bc.SetData(MDATA_DISCONNECT_PRESERVEGROUPS, false);
	mcd.doc = clonedOp->GetDocument();
	mcd.op = clonedOp;
	mcd.mode = MODELINGCOMMANDMODE::POLYGONSELECTION;
	mcd.flags = MODELINGCOMMANDFLAGS::NONE;
	mcd.bc = &bc;

	if (!SendModelingCommand(MCOMMAND_DISCONNECT, mcd)) {
		ApplicationOutput("Disconnect error.");
		return false;
	}
	clonedOp->CopyTo(main, COPYFLAGS::NONE, nullptr);
	clonedOp->CopyMatrixTo(main);
	clonedOp->CopyTagsTo(main, NOTOK, NOTOK, NOTOK, nullptr);
	return true;
}

I should mention that plugin works well with polygon mesh objects and problem appears only with generator objects in isoparm mode.
I guess problem is in Isoparm lines. I've tried to use BUILDFLAGS::ISOPARMS. I cannot use it with non-generator plugin. But i saw few plugins that change count of polygons and still work good. And due to my logic in code i cannot change plugin type to generator.

Although creating a temporary document has been a solution, it still doesn't work good. Cinema4d crash appears randomly while i'm testing it. Usually it happens when i reduce amount of detail, i guess it is something with caches.

What isoparms even are? Why should i use it and how to prevent cinema from crash?
And what about SetIsoparm()? Can i use it in deformer plugin somehow? And should i?

@m_magalhaes No other dependencies. Plugin type is deformer.
Yes, i should probably ask it on Redshift forum. Thanks for reply!

Hello!
My plugin is conflicting with Redshift 3.0.20. Cinema 4D loads infinitely until i disable Redshift, then it loads and plugin works.

Commandline.exe doesn't show any error, each plugin loaded.
Project was compiled with Visual Studio 2017 v141 std17 in Release, Windows 10. Plugin has it's own unique ID from plugincafe.
How can i find out where conflicting part is?

@m_adam maybe you know how to do it in R21? I still need to solve it. Register returns true in R21 but don't even writes output in console.

@m_magalhaes I tried to do same code in R20 and it worked as you said. So what is the difference and how to make it work in R21?

@m_magalhaes Thanks for your reply! I should do it both for R20 and R21/S22. Code above was tested in R21. Is there any major differences in use between R20 and R21?

Hello! I want to implement help in my plugin. I found this topic Static Text Font/Size in Description Resource and tried the same but didn't have any result.
Here is my code:

static Bool PluginsHelpDelegate(const maxon::String& opType, const maxon::String& baseType, const maxon::String& group, const maxon::String& property)
{
	ApplicationOutput("help entry");
	return GeOpenHTML("https://Mysite.my/myplugin#"_s + property);
}

Bool PluginStart()
{
	RegisterPluginHelpDelegate(ID_MAINPLUGIN, PluginsHelpDelegate);
	if (!RegisterMainPlugin())
		return false;
	
	return true;
}

I don't even have output help entry in console. I didn't find any info related to how properly use this and i will appreciate if someone would suggest me.