Dear c4d fellows,
I'm building polygonal objects using c++ in cinema4d (r20).

I have a small question.
I need to create phong tag to make my polygonal surface smooth.
Do I need to ascribe phong tag to each polygon constituing the surface or a single phong tag to the whole surface?

I scanned through different sources of c4d forums and met no formal math definition of a phong angle.
Does somebody have a good source with explanation of phong angle in cinema 4D?

Also, as far as I understand I can easily set up the normal direction to orient the polygons correctly.
Here is a very self explaining example from sdk:

https://developers.maxon.net/docs/Cinema4DCPPSDK/html/page_manual_normaltag.html

But I heard that phong tag might override normal tags.
It is quite scary.

Suppose I set up my normals for each polygon of my surface (with love and care). Then I introduce phong tag and ... all my normals will be destroyed?

Yaroslav.

@ferdinand
Oh, thanks!
Quite a nice idea!

Ferdinand,
just tried

LineObject* spline_linear = spline->GetLineObject(document, precision);

Works like a charm. The closer float "precision" to one the better the approximation, as far as I understand.

One thing, that confuses me is that new object appear in c4d menus with little white"question mark" sign (see picture).
I don't undersytand why.

Here is my piece of code:

LineObject* spline_linear = spline->GetLineObject(document, 0.9);
document->InsertObject(spline_linear, NULL, NULL, 0); // Add it to the OM
spline_linear->Message(MSG_UPDATE);

Oh, I see. Now I can extract all the points from this LineObject and construct a simple linear spline if I need one.
I guess cinema4d doesn't recognize the LineObject. Hence, question mark in menus.

@ferdinand

Dear Ferdinand, thank you for
the comprehensive answer!

(Dear mp5gosu, thank you for your comment too)

Dear Ferdinand, I develop plugin in c++ (using vs2019 and c4d r20) and this is precisely what I meant.
Instead of using beautiful and smooth bezier-curved type splines I want to substitute them with finely approximated linear splines (and I guess SplineObject::GetLineObject is precisely the function I need.) I wonder if there is some control on the number of linear segments approximating the spline. Hopefully, I can get it from the corresponding class declaration.

Yaroslav.

Dear c4d fellows,
I wonder, if there is a buit in method in SplinObject to turn Bezier spline into interpolating linear spline.
Of course, it is simple to code my own function doing exactly this, but may be it is already implemented by c4d creators.

Yaroslav.

@m_magalhaes

Thank you, Manuel!

Dear Frank,
Thanks for the comprehensive reply!
Everything works just as expected!
It is such a scientific joy to explore the cog wheels of the wander-box called cinema4D.

Yaroslav.

Understood!
Thank you, PluginStudent and fwilleke80 so much!
Both of your answers helped me!

I have now the follow-up question.
Forgive me the lack of my expertise.
Here is my code which retrieves the spline drawn by the user.

	BaseDocument* const document = GetActiveDocument();

	SplineObject* spline = nullptr;
	
	BaseObject* object = document->GetActiveObject();
	
	if (object->IsInstanceOf(Ospline))
	spline = ToSpline(object);

Now the question. Suppose the curve is the combination of bezier and linear elements (they are joint).
How do we retrieve

1. all the start and end points of the constituent elements?
2. the control points of Bezier curved elements?

I've looked through SplineObject and PointObject classes.

The only methods that I found are:

const Vector* vec = (*spline).GetPointR();

which is the coordinate of the first point only. But what about the next point?

From SplineObject I found the method GetSplinePoint(t, segment).
If I write

Vector vec1 =  (*spline).GetSplinePoint(1, 0);

I retrieve the coordinate of the last point of the whole curve (i.e. the end point of the last element).
Do you know how to retrieve the rest of the points?

Yaroslav.

Dear c4d fellows,
I've started to develop a plugin for c4d.
Suppose a user drew some spline and made it an active object. I want to read out spline data (bezier coordinates and the rest).

Somehow, in debugging mode I don't see any data.
I use:

BaseObject* spline = document->GetActiveObject();

But then I see in visual studio, that it created a pointer "spline" but that's it.
The only thing I see is that under my variable spline BaseList2D, GeListNode, C4DAtomGoal and C4DAtom are all empty.!

So how does one achieve this?

Yaroslav.

@PluginStudent

Thank you so much! It worked!
Yaroslav.