Yes I understand, but the VBO creation is not a choice of mine, but rather the way vtkContext2D works.
vtkContext2D acts as a high level wrapper that allows display of 2d primitives, by encapsulating some basic stuff (VBO creation, data transfert, shader management, etc …) inside a single call.
As far as I can tell, the current implementation of vtkContext2D is not intended to display huge number of objects, but rather a small bunch of “HUD things” above a 3D scene.
Despite that, it seams vtkContext2D is able to manage some sort of caching mechanism inside the VBO.
Hence my question.