Hello @baca,

Thank you for reaching out to us. I will answer in bullet points.

You are overwriting the wrong method. When setting the ObjectData flag OBJECT_ISSPLINE, one should overwrite GetContour and not GetVirtualObjects. The former is the method to implement spline object generators, while the latter is the method for polygon object generators (and other things). Even when one flags a generator plugin as OBJECT_POINTOBJECT or OBJECT_POLYGONOBJECT, one must do all the document mode dependent drawing and logic oneself. These flags are merely indicators for Cinema 4D that a plugin implements such logic. There is no free lunch here 😞 Drawing a spline in such gradient fashion is possible, but there are no automatisms for it. One must draw multiple line segments to realize drawing a line segment with a gradient. As with most drawing operations, Python is not the ideal language for this, and one might run into slowdowns quickly. While we have internally quite a few cases which mimic point/polygon objects in this fashion, like for example the Bezier object, we have none for splines. I do not see anything right away which would prevent you from implementing such custom spline object, but you are still entering unexplored territory here. You might encounter hard to solve or even unsolvable problems. While it is technically possible to write this yourself, it should be pointed out that the internal implementations all rely on PointObject::DisplayPoints, a non-public method of the PointObject exposed in the public API, to draw the vertices of an object, including selection states and transform gizmos.

So, your code is 'correct' for the most part, at least for a polygon object. You return something in GVO to let Cinema 4D handle the polygon shading and then draw vertices and edges on top of that (which is what you are supposed to do). However, what at least I would not do, is storing the point data in self.LINE_DRAW. I would suggest accessing the cache of the node instead.

In the end it is also not quite clear what you want to do. I understand that you want to draw the vertices and 'gradient' for the line segments of a spline. What is not quite clear to me is if you actually need an object (the stated could also be a tool) and if the user should be able to select and manipulate vertices. I would be best if you could clarify this.

Especially regarding the point of wanting to draw a gradient of line segments, I would strongly suggest moving on to C++, as you will have much better chances to implement such a custom thing in that language.

Cheers,
Ferdinand

SOLVED Prevent Editable Command